WorldWideScience

Sample records for carbon dioxide responsibility

  1. Soil carbon dioxide (CO 2 ) efflux of two shrubs in response to plant ...

    African Journals Online (AJOL)

    Although plant density should affect soil carbon dioxide (CO2) efflux and carbon cycling in semi-arid regions, the effects of plant density on soil CO2 efflux are not well known. This study was performed to investigate the responses of soil CO2 efflux of two dominant shrubs (Caragana korshinkii and Salix psammophila) to ...

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

    Science.gov (United States)

    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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Effects of magnesium sulfate on hemodynamic response to carbon dioxide pneumoperitoneum in patients undergoing laparoscopic cholecystectomy

    OpenAIRE

    Paul, Suhrita; Biswas, Pabitra; Bhattacharjee, Dhurjoti Prosad; Sengupta, Janmejoy

    2013-01-01

    Introduction: Carbon dioxide pneumoperitoneum (PP) for laparoscopic surgery increases arterial pressure, heart rate, and systemic vascular resistance. In this randomized, double blind, prospective clinical study; we investigated the efficacy of magnesium sulfate to prevent adverse hemodynamic response associated with PP in patients undergoing laparoscopic cholecystectomy. Materials and Methods: Sixty patients, of either sex (18-65 years of age), undergoing elective laparoscopic cholecystectom...

  4. Optimization through Response Surface Methodology of a Reactor Producing Methanol by the Hydrogenation of Carbon Dioxide

    OpenAIRE

    Grazia Leonzio

    2017-01-01

    Carbon dioxide conversion and utilization is gaining significant attention worldwide, not only because carbon dioxide has an impact on global climate change, but also because it provides a source for potential fuels and chemicals. Methanol is an important fuel that can be obtained by the hydrogenation of carbon dioxide. In this research, the modeling of a reactor to produce methanol using carbon dioxide and hydrogen is carried out by way of an ANOVA and a central composite design. Reaction te...

  5. Optimization through Response Surface Methodology of a Reactor Producing Methanol by the Hydrogenation of Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Grazia Leonzio

    2017-10-01

    Full Text Available Carbon dioxide conversion and utilization is gaining significant attention worldwide, not only because carbon dioxide has an impact on global climate change, but also because it provides a source for potential fuels and chemicals. Methanol is an important fuel that can be obtained by the hydrogenation of carbon dioxide. In this research, the modeling of a reactor to produce methanol using carbon dioxide and hydrogen is carried out by way of an ANOVA and a central composite design. Reaction temperature, reaction pressure, H2/CO2 ratio, and recycling are the chosen factors, while the methanol production and the reactor volume are the studied responses. Results show that the interaction AC is common between the two responses and allows improvement of the productivity in reducing the volume. A mathematical model for methanol production and reactor volume is obtained with significant factors. A central composite design is used to optimize the process. Results show that a higher productivity is obtained with temperature, CO2/H2 ratio, and recycle factors at higher, lower, and higher levels, respectively. The methanol production is equal to 33,540 kg/h, while the reactor volume is 6 m3. Future research should investigate the economic analysis of the process in order to improve productivity with lower costs.

  6. Carbon Dioxide Fountain

    Science.gov (United States)

    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.)…

  7. Carbon dioxide as chemical feedstock

    National Research Council Canada - National Science Library

    Aresta, M

    2010-01-01

    ... Dioxide as an Inert Solvent for Chemical Syntheses 15 Alessandro Galia and Giuseppe Filardo Introduction 15 Dense Carbon Dioxide as Solvent Medium for Chemical Processes 15 Enzymatic Catalysis in Dense Carbon Dioxide 18 Other Reactions in Dense Carbon Dioxide 19 Polymer Synthesis in Supercritical Carbon Dioxide 20 Chain Polymerizations: Synt...

  8. Physiological responses to exposure to carbon dioxide and human bioeffluents

    DEFF Research Database (Denmark)

    Zhang, Xiaojing; Wargocki, Pawel; Lian, Zhiwei

    2015-01-01

    Present paper describes physiological responses as a result of exposures to CO2 (between 500 ppm to 3,000 ppm) with and without bioeffluents. Twenty-five subjects participated. They were exposed in the climate chamber for 255 minutes in groups of five at a time. During exposure, they performed...

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

    Energy Technology Data Exchange (ETDEWEB)

    Kern, F.H.; Ungerleider, R.M.; Quill, T.J.; Baldwin, B.; White, W.D.; Reves, J.G.; Greeley, W.J. (Duke Univ. Medical Center, Durham, NC (USA))

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    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.

  11. Leaf Structural Acclimation Amplifies Simulated Climate Warming in Response to Elevated Carbon Dioxide.

    Science.gov (United States)

    Kovenock, M.; Swann, A. L. S.

    2016-12-01

    Many plants undergo structural acclimations, or changes in trait morphology, in response to elevated carbon dioxide in field and greenhouse manipulation experiments. These structural acclimations can alter plant functioning - changes in which, taken at the global scale, have been shown to dramatically impact climate. Vegetation modifies Earth's climate by controlling the fluxes of carbon, water, and energy. Of critical importance is a better understanding of how vegetation responses to climate change will feedback on climate. Yet, the climate impacts of plant structural acclimation remain to be tested and quantified. Here we show that one plant structural acclimation - a one third increase in leaf mass per area in response to elevated carbon dioxide in C3 plants globally - significantly impacts climate in earth system model experiments. Consideration of leaf structural acclimation decreases global net primary productivity (-6PgC/yr) compared to the control climate change simulation, representing a flux of carbon dioxide to the atmosphere of similar magnitude to current annual fossil fuel emissions (8PgC/yr). Additional terrestrial warming (+0.3°C globally), especially of the northern extratropics (+0.4°C), results from reduced evapotranspiration and enhanced absorption of solar radiation at the surface. Structural acclimation drives the productivity and evapotranspiration declines by decreasing the leaf area growth associated with carbon fertilization, as greater leaf mass per area increases the cost of building leaf area and productivity fails to fully compensate. Our results suggest that plant structural acclimations, such as leaf mass per area, should be considered in climate projections and provide additional motivation for ecological and physiological experiments that determine plant responses to environment.

  12. Physiological responses to exposure to carbon dioxide and human bioeffluents

    DEFF Research Database (Denmark)

    Zhang, Xiaojing; Wargocki, Pawel; Lian, Zhiwei

    2015-01-01

    Present paper describes physiological responses as a result of exposures to CO2 (between 500 ppm to 3,000 ppm) with and without bioeffluents. Twenty-five subjects participated. They were exposed in the climate chamber for 255 minutes in groups of five at a time. During exposure, they performed...... different cognitive tasks and assessed their comfort and acute health symptoms. Besides, the following were determined: heart rate, blood pressure, oxygen saturation of blood, respiration rate, minute ventilation rate, nasal peak flow, forced expiratory volume, and the end-tidal CO2 pressure (ETCO2). Saliva...... samples were collected to analyze stress biomarkers. During exposure to CO2 with and without bioeffluents at 3,000 ppm, ETCO2 and minute ventilation rate were higher, while nasal peak flow decreased. These exposures caused also the increased heart rate during typing sessions. During exposures to CO2...

  13. Response of Agronomic and Forest Species to Elevated Atmospheric Carbon Dioxide

    Science.gov (United States)

    Rogers, Hugo H.; Thomas, Judith F.; Bingham, Gail E.

    1983-04-01

    The effects of atmospheric carbon dioxide on corn, soybeans, loblolly pine, and sweetgum were studied in the field during a growing season. The plants were exposed to a range of concentrations of carbon dioxide day and night in open-topped, flow-through chambers. At a mean daytime carbon dioxide concentration of 910 parts per million, increases in total biomass ranged from 157 to 186 percent of the control values. Seed yield and wood volume increased and there were changes in plant anatomy and form. Net photosynthesis increased with increasing carbon dioxide concentration in soybeans and sweetgum, but was unaffected in corn. Water use efficiency also increased in corn, soybeans, and sweetgum.

  14. Carbon dioxide and climate

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Soil carbon dioxide (CO2) efflux of two shrubs in response to plant ...

    African Journals Online (AJOL)

    Jane

    2010-10-11

    , Institute of Soil and Water ... Although plant density should affect soil carbon dioxide (CO2) efflux and carbon cycling in semi-arid regions, the effects ...... root and microbial contributions to soil respiration in Leymus chinensis ...

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  17. Carbon dioxide sensor

    Science.gov (United States)

    Dutta, Prabir K [Worthington, OH; Lee, Inhee [Columbus, OH; Akbar, Sheikh A [Hilliard, OH

    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).

  18. Carbon dioxide recycling

    Science.gov (United States)

    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 ...

  19. Physiological responses of Pinus sylvestris to changing carbon dioxide and ozone concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Holopainen, T. [Kuopio Univ. (Finland). Dept. of Ecology and Environmental Science; Palomaeki, V. [Joensuu Univ. (Finland). Faculty of Forestry; Helmisaari, H.S. [Finnish Forest Research Inst., Helsinki (Finland)] [and others

    1996-12-31

    The objective of this research is to study the effects of elevated ozone, carbon dioxide and their combination on ultrastructural, physiological and biochemical responses of Scots pine needles and how these effects are reflected to photosynthesis, carbohydrate and nutrient allocation and finally to shoot and root growth of trees. In addition the interactions of the studied trees and mycorrhizal fungi as well as insect herbivores are studied. The exposures have been running only for two growing periods and it seems necessary to continue the experiment over the third growing season in 1996. Since the analyses are partially incomplete, only preliminary conclusions are possible at the moment. The slightly increased shoot growth and needle width and increased amount of starch in chloroplasts point to the slight stimulating effect of elevated CO{sub 2} among the chamber treatments. Altogether the growth of the seedlings was best in the chamberless treatment indicating a negative chamber effect. The elevated ozone significantly increased the chlorotic mottling and overall yellowing of second year needles as well as caused increased density of chloroplast stroma and declined photosynthesis, all these responses being often related to ozone exposures. The ozone related responses appeared at both CO{sub 2} levels indicating no clear protection due to elevated CO{sub 2}. The ozone or carbon dioxide treatments were not able to significantly change nutrient concentrations, insect herbivory or carbon allocation among the secondary compounds of needles. A tendency of increased carbon allocation to fine roots due to ozone but not so clearly to CO{sub 2} was observed

  20. Behavioural responses of Ixodes ricinus nymphs to carbon dioxide and rodent odour.

    Science.gov (United States)

    VAN Duijvendijk, G; Gort, G; Sprong, H; Takken, W

    2017-06-01

    Many haematophagous ectoparasites use carbon dioxide (CO2 ) and host odour to detect and locate their hosts. The tick Ixodes ricinus (Linnaeus) (Ixodida: Ixodidae) walks only small distances and quests in vegetation until it encounters a host. The differential effects of CO2 and host odour on the host-finding behaviour of I. ricinus have, however, never been clarified and hence represent the subject of this study. The effects of CO2 and odour from bank voles on the activation and attraction of I. ricinus nymphs were analysed in a Y-tube olfactometer. Carbon dioxide evoked a response in the absence and presence of host odour, but did not attract nymphs. Host odour, however, did not evoke a response but did attract nymphs in the absence and presence of CO2 . The current results show that CO2 is an activator, but not an attractant, and that host odour is an attractant, but not an activator, of I. ricinus nymphs, and provide ecological insights into the host-finding behaviour of I. ricinus. © 2016 The Royal Entomological Society.

  1. Carbon dioxide test as an additional clinical measure of treatment response in panic disorder

    Directory of Open Access Journals (Sweden)

    Valença Alexandre M.

    2002-01-01

    Full Text Available OBJECTIVE: We aim to determine if a treatment with a dose of clonazepam - 2 mg/day, for 6 weeks, blocks spontaneous panic attacks and the ones induced by the inhalation of 35% carbon dioxide (CO2 in panic disorder (PD patients. The CO2 challenge-test may be a useful addition tool for measuring the pharmacological response during the initial phase (6 weeks in the treatment of PD. METHOD: Eighteen PD patients drug free for a week participated in a carbon dioxide challenge test. Fourteen had a panic attack and were openly treated for a 6-week period with clonazepam. At the end of the 6-week period they were submitted again to the CO2 challenge test. RESULTS: After 6 weeks of treatment with clonazepam, 12 of 14 PD patients (85.7% did not have a panic attack after the CO2 challenge test. Just 2 of 14 patients (14.3% had a panic attack after the CO2 challenge test. Ten of 14 (71.4% PD patients had panic free status after clonazepam treatment. The 2 patients who had a panic attack in the sixth week, after the CO2 test, did not have panic free status after the treatment with clonazepam. CONCLUSION: The CO2-test may be a valid tool for testing and predicting the drug response.

  2. Balancing atmospheric carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Goreau, T.J. (Discovery Bay Marine Laboratory, Univ. of the West Indies (JM))

    1990-01-01

    Rising carbon dioxide and global temperatures are causing increasing worldwide concern, and pressure towards an international law of the atmosphere is rapidly escalating, yet widespread misconceptions about the greenhouse effect's inevitability, time scale, and causes have inhibited effective consensus and action. Observations from Antarctic ice cores, Amazonian rain forests, and Carribean coral reefs suggest that the biological effects of climate change may be more severe than climate models predict. Efforts to limit emissions from fossil-fuel combustion alone are incapable of stabilizing levels of carbon dioxide in the atmosphere. Stabilizing atmospheric carbon dioxide requires coupled measures to balance sources and sinks of the gas, and will only be viable with large-scale investments in increased sustainable productivity on degraded tropical soils, and in long-term research on renewable energy and biomass product development in the developing countries. A mechanism is outlined which directly links fossil-fuel combustion sources of carbon dioxide to removal via increasing biotic productivity and storage. A preliminary cost-benefit analysis suggests that such measures are very affordable, costing far less than inaction. (With 88 refs.).

  3. Carbon dioxide dangers demonstration model

    Science.gov (United States)

    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.

  4. The Role of Nitrogen Dynamics in the Responses of Terrestrial Carbon Dynamics to Changes in Atmospheric Carbon Dioxide, Climate, and Land Use

    Science.gov (United States)

    McGuire, A. D.; Melillo, J.; Kicklighter, D.; Joyce, L.

    2007-12-01

    While it has long been appreciated that alterations of the nitrogen cycle can substantially affect the carbon dynamics of terrestrial ecosystems, most large-scale models of terrestrial carbon dynamics have ignored carbon-nitrogen interactions in making projections of how carbon dynamics will respond to changes in atmospheric carbon dioxide, climate, and land use. Numerous experimental studies have documented that the uptake of carbon by terrestrial ecosystems is enhanced by nitrogen fertilization under baseline and elevated atmospheric carbon dioxide concentrations. Ecosystem warming studies often identify that the uptake of carbon is enhanced when mineralization of soil organic nitrogen increases in response to warming, but the response often depends on how warming affects soil moisture. Nitrogen amendments are a standard practice in heavily managed agro-forestry ecosystems because of the enhanced response of plant growth to nitrogen fertilization. We have used the Terrestrial Ecosystem Model (TEM) as a tool to explore the regional and global implications of how carbon-nitrogen interactions may influence the responses of terrestrial carbon dynamics to environmental change and land use. Comparisons of the model with and without nitrogen dynamics indicate that the response of carbon uptake to increases in atmospheric carbon dioxide are clearly constrained by nitrogen dynamics. In contrast, carbon uptake is enhanced in situations in which warming enhances the mineralization of soil organic nitrogen, and this response can lead to increases in vegetation carbon storage that are greater than losses of carbon from increases in decomposition of soil organic matter. Land use can result in substantial depletion of nitrogen from terrestrial ecosystems in the harvest of agricultural products. As substantial sink activity is associated with forest re-growth after agricultural land abandonment, we conducted simulations with TEM in the eastern United State to evaluate to role of

  5. Exposure to moderate concentrations of tropospheric ozone impairs tree stomatal response to carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Onandia, Gabriela [Department of Plant and Environmental Sciences, University of Gothenburg, P. O. Box 461, SE-405 30 Goeteborg (Sweden); Cavanilles Institute of Biodiversity and Evolutionary Biology, Department of Microbiology and Ecology, University of Valencia, E-46100 Burjassot, Valencia (Spain); Olsson, Anna-Karin; Barth, Sabine [Department of Plant and Environmental Sciences, University of Gothenburg, P. O. Box 461, SE-405 30 Goeteborg (Sweden); King, John S. [Department of Forestry and Environmental Resources, Campus Box 8002, North Carolina State University, Raleigh, NC 27695 (United States); Uddling, Johan, E-mail: johan.uddling@dpes.gu.se [Department of Plant and Environmental Sciences, University of Gothenburg, P. O. Box 461, SE-405 30 Goeteborg (Sweden)

    2011-10-15

    With rising concentrations of both atmospheric carbon dioxide (CO{sub 2}) and tropospheric ozone (O{sub 3}), it is important to better understand the interacting effects of these two trace gases on plant physiology affecting land-atmosphere gas exchange. We investigated the effect of growth under elevated CO{sub 2} and O{sub 3}, singly and in combination, on the primary short-term stomatal response to CO{sub 2} concentration in paper birch at the Aspen FACE experiment. Leaves from trees grown in elevated CO{sub 2} and/or O{sub 3} exhibited weaker short-term responses of stomatal conductance to both an increase and a decrease in CO{sub 2} concentration from current ambient level. The impairement of the stomatal CO{sub 2} response by O{sub 3} most likely developed progressively over the growing season as assessed by sap flux measurements. Our results suggest that expectations of plant water-savings and reduced stomatal air pollution uptake under rising atmospheric CO{sub 2} may not hold for northern hardwood forests under concurrently rising tropospheric O{sub 3}. - Exposure to moderate concentrations of tropospheric ozone impairs stomatal CO{sub 2} responsiveness of birch in the Aspen FACE experiment.

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

    Directory of Open Access Journals (Sweden)

    Sara E. Hartmann

    2015-09-01

    Full Text Available 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, p0.05 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.

  7. Responses of selected species of marine phytoplankton to increasing carbon dioxide and light

    OpenAIRE

    Barcelos e Ramos, Joana

    2009-01-01

    Atmospheric carbon dioxide (CO2) concentrations have been increasing since the industrial revolution and are expected to almost triple from pre-industrial values by the year 2100. CO2 enters the ocean by atmosphere-surface ocean gas exchange, decreasing carbonate ion (CO32-) concentrations and pH (ocean acidification). Additionally, the rise of CO2 concentrations and other green-house gases in the atmosphere, increase global average temperatures in the air and, consequently, in the surface oc...

  8. Transcriptome profiling of the microalga Chlorella pyrenoidosa in response to different carbon dioxide concentrations.

    Science.gov (United States)

    Sun, Xue; Shen, Jia; Bai, Fengwei; Xu, Nianjun

    2016-10-01

    To enrich our knowledge of carbon dioxide (CO2)-concentrating mechanism (CCM) in eukaryotic algae, we used high-throughput sequencing to investigate the transcriptome profiling of the microalga Chlorella pyrenoidosa (Chlorophyta) response to different CO2 levels. Altogether, 53.86 million (M) and 62.10M clean short reads of 100 nucleotides (nt) were generated from this microalga cultured at 4-fold air CO2 (control) and air CO2 concentrations by Illumina sequencing. A total of 32,662 unigenes were assembled from the two pooled samples. With an E-value cut-off of 1e-5, 9590, 6782, 5954, and 9092 unigenes were annotated in NR, Gene Ontology (GO), Eukaryotic Cluster of Orthologous Groups of proteins (KOG), and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, respectively. After screening, 51 differentially expressed unigenes were up-regulated and 8 were down-regulated in the air CO2 group, relative to the control. The transcript levels of eight differentially expressed unigenes were validated by real-time quantitative PCR, which manifested that thioredoxin-like protein, laminin subunit beta-1, and chlorophyll a/b binding protein might be associated with the utilization of inorganic carbon at low CO2 levels. Copyright © 2016 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    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...

  10. Behavioural responses of Ixodes ricinus nymphs to carbon dioxide and rodent odour

    NARCIS (Netherlands)

    Duijvendijk, van G.; Gort, G.; Sprong, H.; Takken, W.

    2017-01-01

    Many haematophagous ectoparasites use carbon dioxide (CO2) and host odour to detect and locate their hosts. The tick Ixodes ricinus (Linnaeus) (Ixodida: Ixodidae) walks only small distances and quests in vegetation until it encounters a host. The differential effects of CO2 and host odour on the

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  12. Carbon Dioxide Fixation by Microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Lynch, Victoria H.; Calvin, Melvin

    1951-07-24

    Resting cells of eleven microorganisms were exposed to radioactive carbon dioxide for 40 minutes. The radioactive compounds formed during this time were separated and identified by paper chromatography. Resting cells of Lactobacillus casei fixed no carbon dioxide and growing cells fixed carbon dioxide primarily in malic and aspartic acids. All of the radioactive compounds formed could have become radioactive by reversal of known decarboxylation reactions.

  13. Responses of Metabolites in Soybean Shoot Apices to Changing Atmospheric Carbon Dioxide Concentrations

    Directory of Open Access Journals (Sweden)

    Richard Sicher

    2012-01-01

    Full Text Available Soybean seedlings were grown in controlled environment chambers with CO2 partial pressures of 38 (ambient and 72 (elevated Pa. Five or six shoot apices were harvested from individual 21- to 24-day-old plants. Metabolites were analyzed by gas chromatography and, out of 21 compounds, only sucrose and fructose increased in response to CO2 enrichment. One unidentified metabolite, Unk-21.03 decreased up to 80% in soybean apices in response to elevated CO2. Levels of Unk-21.03 decreased progressively when atmospheric CO2 partial pressures were increased from 26 to 100 Pa. Reciprocal transfer experiments showed that Unk-21.03, and sucrose in soybean apices were altered slowly over several days to changes in atmospheric CO2 partial pressures. The mass spectrum of Unk-21.03 indicated that this compound likely contained both an amino and carboxyl group and was structurally related to serine and aspartate. Our findings suggested that CO2 enrichment altered a small number of specific metabolites in soybean apices. This could be an important step in understanding how plant growth and development are affected by carbon dioxide enrichment.

  14. Effects of magnesium sulfate on hemodynamic response to carbon dioxide pneumoperitoneum in patients undergoing laparoscopic cholecystectomy.

    Science.gov (United States)

    Paul, Suhrita; Biswas, Pabitra; Bhattacharjee, Dhurjoti Prosad; Sengupta, Janmejoy

    2013-01-01

    Carbon dioxide pneumoperitoneum (PP) for laparoscopic surgery increases arterial pressure, heart rate, and systemic vascular resistance. In this randomized, double blind, prospective clinical study; we investigated the efficacy of magnesium sulfate to prevent adverse hemodynamic response associated with PP in patients undergoing laparoscopic cholecystectomy. Sixty patients, of either sex (18-65 years of age), undergoing elective laparoscopic cholecystectomy were randomly allocated in one of the two groups containing 30 patients each. Group M received magnesium sulfate 30 mg/kg intravenously as a bolus before PP. Group C received same volume of 0.9% saline. Mean arterial pressure and heart rate were significantly less throughout the period of pneumoperitoneum in patients of group M. Intravenous labetalol was required in 40% (12 out of 30) of the patients in group C to control intraoperative hypertension and it was clinically significant in comparison to group M. Magnesium sulfate administered before PP attenuates adverse hemodynamic response and provides hemodynamic stability during PP created for laparoscopic surgery.

  15. Carbon dioxide sequestration by mineral carbonation

    NARCIS (Netherlands)

    Huijgen, W.J.J.

    2007-01-01

    The increasing atmospheric carbon dioxide (CO2) concentration, mainly caused by fossil fuel combustion, has lead to concerns about global warming. A possible technology that can contribute to the reduction of carbon dioxide emissions is CO2 sequestration by mineral carbonation. The basic concept

  16. Antibacterial Properties of Visible-Light-Responsive Carbon-Containing Titanium Dioxide Photocatalytic Nanoparticles against Anthrax

    Directory of Open Access Journals (Sweden)

    Der-Shan Sun

    2016-12-01

    Full Text Available The bactericidal activity of conventional titanium dioxide (TiO2 photocatalyst is effective only on irradiation by ultraviolet light, which restricts the applications of TiO2 for use in living environments. Recently, carbon-containing TiO2 nanoparticles [TiO2(C NP] were found to be a visible-light-responsive photocatalyst (VLRP, which displayed significantly enhanced antibacterial properties under visible light illumination. However, whether TiO2(C NPs exert antibacterial properties against Bacillus anthracis remains elusive. Here, we evaluated these VLRP NPs in the reduction of anthrax-induced pathogenesis. Bacteria-killing experiments indicated that a significantly higher proportion (40%–60% of all tested Bacillus species, including B. subtilis, B. cereus, B. thuringiensis, and B. anthracis, were considerably eliminated by TiO2(C NPs. Toxin inactivation analysis further suggested that the TiO2(C NPs efficiently detoxify approximately 90% of tested anthrax lethal toxin, a major virulence factor of anthrax. Notably, macrophage clearance experiments further suggested that, even under suboptimal conditions without considerable bacterial killing, the TiO2(C NP-mediated photocatalysis still exhibited antibacterial properties through the reduction of bacterial resistance against macrophage killing. Our results collectively suggested that TiO2(C NP is a conceptually feasible anti-anthrax material, and the relevant technologies described herein may be useful in the development of new strategies against anthrax.

  17. Long-term ocean oxygen depletion in response to carbon dioxide emissions from fossil fuels

    DEFF Research Database (Denmark)

    Shaffer, G.; Olsen, S.M.; Pedersen, Jens Olaf Pepke

    2009-01-01

    Ongoing global warming could persist far into the future, because natural processes require decades to hundreds of thousands of years to remove carbon dioxide from fossil-fuel burning from the atmosphere(1-3). Future warming may have large global impacts including ocean oxygen depletion and assoc......Ongoing global warming could persist far into the future, because natural processes require decades to hundreds of thousands of years to remove carbon dioxide from fossil-fuel burning from the atmosphere(1-3). Future warming may have large global impacts including ocean oxygen depletion...... solubility from surface-layer warming accounts for most of the enhanced oxygen depletion in the upper 500 m of the ocean. Possible weakening of ocean overturning and convection lead to further oxygen depletion, also in the deep ocean. We conclude that substantial reductions in fossil-fuel use over the next...

  18. Physiological responses of laying hens during whole-house killing with carbon dioxide.

    Science.gov (United States)

    McKeegan, D E F; Sparks, N H C; Sandilands, V; Demmers, T G M; Boulcott, P; Wathes, C M

    2011-12-01

    1. Poultry on farms are sometimes required to be killed in an emergency, such as during a disease epidemic, yet none of the available methods are ideal. Whole-house carbon dioxide (CO(2)) administration has practical advantages, but gives rise to welfare concerns. 2. The study measured the body temperature, respiration, cardiac and brain activity (EEG) responses of 10 adult hens placed in tiered cages in a deep pit house while the entire flock (28,000 end-of-lay hens) was killed with CO(2). Video and thermographic images were also recorded. Liquid CO(2) was injected into the building producing a gaseous concentration of 45% within 19 min. 3. Those hens nearest the gas delivery site showed delayed respiratory, cardiac and EEG responses compared with those at more distant locations. Although sub-zero temperatures were recorded in the immediate vicinity of some birds, body temperatures indicated that they did not die of hypothermia. 4. EEG characteristics strongly associated with unconsciousness were used to determine an unequivocal time to loss of consciousness; this ranged from 6·0 to 10·5 (average 7·8) min after onset of gas injection. Distinctive cardiac and respiratory responses were seen following gas exposure; in particular, birds responded to inhalation of CO(2) by deep breathing. 5. The primary welfare concern is the duration of unpleasant respiratory effects, such as deep breathing, while the birds were substantively conscious. However, the concentration of CO(2) to which the birds were exposed while conscious would not have stimulated nasal and oral nociceptors. Time to death varied between 12·0 and 22·1 min after gas delivery.

  19. Scots pine responses to elevated temperature and carbon dioxide concentration: growth and wood properties.

    Science.gov (United States)

    Kilpeläinen, Antti; Peltola, Heli; Ryyppö, Aija; Kellomäki, Seppo

    2005-01-01

    Growth and wood properties of 20-year-old Scots pine (Pinus sylvestris L.) trees were studied for 6 years in 16 closed chambers providing a factorial combination of two temperature regimes (ambient and elevated) and two carbon dioxide concentrations ([CO2]) (ambient and twice ambient). The elevation of temperature corresponded to the predicted effect at the site of a doubling in atmospheric [CO2]. Annual height and radial growth and wood properties were analyzed during 1997-2002. Physical wood properties analyzed included early- and latewood widths and their proportions, intra-ring wood densities, early- and latewood density and mean fiber length. Chemical wood properties analyzed included concentrations of acetone-soluble extractives, lignin, cellulose and hemicellulose. There were no significant treatment effects on height growth during the 6-year study. Elevated [CO2] increased ring width by 66 and 47% at ambient and elevated temperatures, respectively. At ambient [CO2], elevated temperature increased ring width by 19%. Increased ring width in response to elevated [CO2] resulted from increases in both early- and latewood width; however, there was no effect of the treatments on early- and latewood proportions. Mean wood density, earlywood density and fiber length increased in response to elevated temperature. The chemical composition of wood was affected by elevated [CO2], which reduced the cellulose concentration, and by elevated temperature, which reduced the concentration of acetone-soluble extractives. Thus, over the 6-year period, radial growth was significantly increased by elevated [CO2], and some wood properties were significantly affected by elevated temperature or elevated [CO2], or both, indicating that climate change may affect the material properties of wood.

  20. End-tidal carbon dioxide as a measure of stress response to clustered nursing interventions in neurologic patients.

    Science.gov (United States)

    Genzler, Laura; Johnson, Pamela Jo; Ghildayal, Neha; Pangarakis, Sarah; Sendelbach, Sue

    2013-05-01

    Guidelines recommend rest periods between nursing interventions for patients with a neurologic diagnosis but do not specify a safe number of interventions. To examine the physiological stress response to clustered nursing interventions in neurologic patients receiving mechanical ventilation. Prospective, comparative, descriptive design to examine effects of clustered interventions (≥6 interventions in a single nursing interaction) versus nonclustered interventions on patients' stress. Stress response was defined as a 10% change in end-tidal carbon dioxide from before the interaction to (1) 5 and 10 minutes after the start of the interaction, (2) at the end of the interaction, and (3) 15 minutes after the interaction. The mean percent change in end-tidal carbon dioxide at 5 minutes differed significantly between patients with clustered interventions and patients with nonclustered interventions (6.7% vs -0.2%; P = .001). Patients with clustered interventions were significantly more likely than patients with low clustering to exhibit a stress response at 5 minutes (24.3% vs 0%; P = .01). Neurologic patients receiving mechanical ventilation who experienced 6 or more clustered nursing interventions showed a higher mean change in end-tidal carbon dioxide than did patients who received fewer than 6 clustered interventions. These findings suggest that providing fewer interventions during 1 nursing interaction may minimize induced stress in neurologic patients receiving mechanical ventilation.

  1. Forecasting carbon dioxide emissions.

    Science.gov (United States)

    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. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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 0.10). Neither soil temperature, nor soil moisture appeared to be correlated with soil CO2 efflux (p > 0.10). By June 2012, after senescence and dry-out, all soil CO2 effluxes were lower than in April, and

  4. Physiological responses during exposure to carbon dioxide and bioeffluents at levels typically occurring indoors

    DEFF Research Database (Denmark)

    Zhang, X.; Wargocki, Pawel; Lian, Z.

    2017-01-01

    Twenty-five subjects were exposed to different levels of carbon dioxide (CO2) and bioeffluents. The ventilation rate was set high enough to create a reference condition of 500 ppm CO2 with subjects present; additional CO2 was then added to supply air to reach levels of 1000 or 3000 ppm...... and heart rate decreased less than the changes that occurred in the reference condition. Exposure to bioeffluents, when metabolically generated CO2 was at 3000 ppm, significantly increased diastolic blood pressure and salivary α-amylase level compared with pre-exposure levels, and reduced the performance...

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

    Energy Technology Data Exchange (ETDEWEB)

    Hossain, Md. Sohrab [Department of Environmental Technology, School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang (Malaysia); Nik Ab Rahman, Nik Norulaini [School of Distance Education, Universiti Sains Malaysia, 11800 Penang (Malaysia); Balakrishnan, Venugopal [Institute for Research in Molecular Medicine, Universiti Sains Malaysia, 11800 Penang (Malaysia); Alkarkhi, Abbas F.M. [Department of Environmental Technology, School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang (Malaysia); Ahmad Rajion, Zainul [School of Dental Science, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia); Ab Kadir, Mohd Omar, E-mail: akmomar@usm.my [Department of Environmental Technology, School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang (Malaysia)

    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. Carbon dioxide exchange in three tundra sites show a dissimilar response to environmental variables

    DEFF Research Database (Denmark)

    Mbufong, Herbert Njuabe; Lund, Magnus; Christensen, Torben Røjle

    2015-01-01

    Due to the heterogeneity of the Arctic tundra, general current understanding of net carbon (C) uptake in these ecosystems is poorly developed. This study investigates the dependency of carbon dioxide (CO2) fluxes on environmental, meteorological and vegetation properties in high, low and subarctic...... tundra sites for the purpose of exposing the environmental, meteorological and vegetation factors, especially season length, that drive CO2 fluxes in disparate tundra environments. Partitioning CO2 fluxes and redefining seasons in the same manner improved our interpretation of the factors affecting flux...... variability. An improved understanding of the control of ancillary variables on net ecosystem exchange (NEE), gross primary production (GPP) and ecosystem respiration (Re) will improve the accuracy with which CO2 exchange seasonality in Arctic tundra ecosystems is modelled. Fluxes were measured with the eddy...

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

    Science.gov (United States)

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

    2017-01-01

    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

    Energy Technology Data Exchange (ETDEWEB)

    Malmstroem, C.M.; Field, C.B. [Stanford Univ., CA (United States)]|[Carnegie Institution, Stanford, CA (United States)

    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. Reducing carbon dioxide to products

    Science.gov (United States)

    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.

  10. Recuperative supercritical carbon dioxide cycle

    Science.gov (United States)

    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.

  11. Method for carbon dioxide sequestration

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-12-05

    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) and water or bine 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.

  12. Human responses to carbon dioxide, a follow-up study at recommended exposure limits in non-industrial environments

    DEFF Research Database (Denmark)

    Zhang, Xiaojing; Wargocki, Pawel; Lian, Zhiwei

    2016-01-01

    To extend the results of a previous study on the effects of carbon dioxide (CO2) and bioeffluents on humans, the new study reported in this paper was carried out. The purpose of this study was to examine, whether exposure to CO2 at 5000 ppm would cause sensory discomfort, evoke acute health...... symptoms, reduce the performance of cognitive tasks, or result in changes in physiological responses. The outdoor air supply rate was set high enough in a low-emission stainless-steel climate chamber to create a reference condition with CO2 at 500 ppm when subjects were present, and chemically pure CO2...

  13. Method for carbon dioxide splitting

    Science.gov (United States)

    Miller, James E.; Diver, Jr., Richard B.; Siegel, Nathan P.

    2017-02-28

    A method for splitting carbon dioxide via a two-step metal oxide thermochemical cycle by heating a metal oxide compound selected from an iron oxide material of the general formula A.sub.xFe.sub.3-xO.sub.4, where 0.ltoreq.x.ltoreq.1 and A is a metal selected from Mg, Cu, Zn, Ni, Co, and Mn, or a ceria oxide compound of the general formula M.sub.aCe.sub.bO.sub.c, where 0gas mixture, adding carbon dioxide, and heating to a temperature less than approximately 1400 C, thereby producing carbon monoxide gas and the original metal oxide compound.

  14. Magnesite disposal of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Olfaction in the Queensland fruit fly, Bactrocera tryoni. II: Response spectra and temporal encoding characteristics of the carbon dioxide receptors.

    Science.gov (United States)

    Hull, C D; Cribb, B W

    2001-05-01

    Single-unit electrophysiology was used to record the nerve impulses from the carbon dioxide receptors of female Queensland fruit flies, Bactroera tryoni. The receptors responded to stimulation in a phasic-tonic manner and also had a period of inhibition of the nerve impulses after the end of stimulation. at high stimulus intensities. The cell responding to carbon dioxide was presented with a range of environmental odorants and found to respond to methyl butyrate and 2-butanone. The coding characteristics of the carbon dioxide cell and the ability to detect other odorants are discussed, with particular reference to the known behavior of the fly.

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

    Science.gov (United States)

    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. Direct quantitative comparison of molecular responses in photodamaged human skin to fractionated and fully ablative carbon dioxide laser resurfacing.

    Science.gov (United States)

    Orringer, Jeffrey S; Sachs, Dana L; Shao, Yuan; Hammerberg, Craig; Cui, Yilei; Voorhees, John J; Fisher, Gary J

    2012-10-01

    Fractionated ablative laser resurfacing has become a widely used treatment modality. Its clinical results are often found to approach those of traditional fully ablative laser resurfacing. To directly compare the molecular changes that result from fractionated and fully ablative carbon dioxide (CO(2)) laser resurfacing in photodamaged human skin. Photodamaged skin of 34 adult volunteers was focally treated at distinct sites with a fully ablative CO(2) laser and a fractionated CO(2) laser. Serial skin samples were obtained at baseline and several time points after treatment. Real-time reverse transcriptase polymerase chain reaction technology and immunohistochemistry were used to quantify molecular responses to each type of laser treatment. Fully ablative and fractionated CO(2) laser resurfacing induced significant dermal remodeling and collagen induction. After a single treatment, fractionated ablative laser resurfacing resulted in collagen induction that was approximately 40% to 50% as pronounced as that induced by fully ablative laser resurfacing. The fundamental cutaneous responses that result from fully ablative and fractionated carbon dioxide laser resurfacing are similar but differ in magnitude and duration, with the fully ablative procedure inducing relatively greater changes including more pronounced collagen induction. However, the molecular data reported here provide substantial support for fractionated ablative resurfacing as an effective treatment modality for improving skin texture. © 2012 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

  18. Temporal biomass dynamics of an Arctic plankton bloom in response to increasing levels of atmospheric carbon dioxide

    NARCIS (Netherlands)

    Schulz, K.G.; Bellerby, R.G.J.; Brussaard, C.P.D.; Büdenbender, J.; Czerny, J.; Engel, A.; Fischer, M.; Koch-Klavsen, S.; Krug, S.A.; Lischka, S.; Ludwig, A.; Meyerhöfer, M.; Nondal, G.; Silyakova, A.; Stuhr, A.; Riebesell, U.

    2013-01-01

    Ocean acidification and carbonation, driven by anthropogenic emissions of carbon dioxide (CO2), have been shown to affect a variety of marine organisms and are likely to change ecosystem functioning. High latitudes, especially the Arctic, will be the first to encounter profound changes in carbonate

  19. Carbon Dioxide Information Center thesaurus

    Energy Technology Data Exchange (ETDEWEB)

    Millemann, R.E.; Cushman, R.M.

    1986-04-01

    This thesaurus lists the keywords (including narrower, broader, and related terms, as well as forbidden terms) used by the Carbon Dioxide Information Center for the input and retrieval of records for its Bibliographic Information System (BIS), BIS is a specialized bibliographic data base on carbon dioxide and climate. It is being merged into the Department of Energy's Energy Data Base (EDB). The keywords used in the BIS Thesaurus are also used in the much larger EDB thesaurus so EDB may be searched for CO2 references using either thesaurus.

  20. Carbon Dioxide Absorption Heat Pump

    Science.gov (United States)

    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. Carbon Dioxide Embolism during Laparoscopic Surgery

    Science.gov (United States)

    Park, Eun Young; Kwon, Ja-Young

    2012-01-01

    Clinically significant carbon dioxide embolism is a rare but potentially fatal complication of anesthesia administered during laparoscopic surgery. Its most common cause is inadvertent injection of carbon dioxide into a large vein, artery or solid organ. This error usually occurs during or shortly after insufflation of carbon dioxide into the body cavity, but may result from direct intravascular insufflation of carbon dioxide during surgery. Clinical presentation of carbon dioxide embolism ranges from asymptomatic to neurologic injury, cardiovascular collapse or even death, which is dependent on the rate and volume of carbon dioxide entrapment and the patient's condition. We reviewed extensive literature regarding carbon dioxide embolism in detail and set out to describe the complication from background to treatment. We hope that the present work will improve our understanding of carbon dioxide embolism during laparoscopic surgery. PMID:22476987

  2. High capacity carbon dioxide sorbent

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Process for sequestering carbon dioxide and sulfur dioxide

    Science.gov (United States)

    Maroto-Valer, M Mercedes [State College, PA; Zhang, Yinzhi [State College, PA; Kuchta, Matthew E [State College, PA; Andresen, John M [State College, PA; Fauth, Dan J [Pittsburgh, PA

    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.

  4. Modelling Sublimation of Carbon Dioxide

    Science.gov (United States)

    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…

  5. Growth and yield responses of potato to mixtures of carbon dioxide and ozone.

    Science.gov (United States)

    Heagle, A S; Miller, J E; Pursley, W A

    2003-01-01

    Elevated carbon dioxide (CO2) concentrations in the atmosphere can stimulate plant growth and yield, whereas ground-level ozone (O3) concentrations cause the opposite effect in many areas of the world. Recent experiments show that elevated CO2 can protect some plants from O3 stress, but this has not been tested for most crop species. Our objective was to determine if elevated CO2 protects Irish potato (Solanum tuberosum L.) from foliar injury and suppression of growth and yield caused by O3. An O3-resistant cultivar (Superior) and an O3-sensitive cultivar (Dark Red Norland) were exposed from within 10 d after emergence to maturity to mixtures of three CO2 and three O3 treatments in open-top field chambers. The three CO2 treatments were ambient (370 microL L(-1)) and two treatments with CO2 added to ambient CO2 for 24 h d(-1) (540 and 715 microL L(-1)). The O3 treatments were charcoal-filtered air (15 nL L(-1)), nonfiltered air (45 nL L(-1)), and nonfiltered air with O3 added for 12 h d(-1) (80 nL L(-1)). Elevated O3 and CO2 caused extensive foliar injury of Dark Red Norland, but caused only slight injury of Superior. Elevated CO2 increased growth and tuber yield of both cultivars, whereas elevated O3 generally suppressed growth and yield, mainly of Dark Red Norland. Elevated CO2 appeared to protect Dark Red Norland from O3-induced suppression of shoot, root, and tuber weight as measured at midseason but did not protect either cultivar from O3 stress at the final harvest. The results further illustrate the difficulty in predicting effects of O3 + CO2 mixtures based on the effects of the individual gases.

  6. Carbon Dioxide (CO2) in Blood

    Science.gov (United States)

    ... https://medlineplus.gov/labtests/carbondioxideco2inblood.html Carbon Dioxide (CO2) in Blood To use the sharing features on ... please enable JavaScript. What is a Carbon Dioxide (CO2) Blood Test? Carbon dioxide (CO2) is an odorless, ...

  7. 21 CFR 582.1240 - Carbon dioxide.

    Science.gov (United States)

    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 generally...

  8. Method for carbon dioxide splitting

    Energy Technology Data Exchange (ETDEWEB)

    Miller, James E.; Diver, Jr., Richard B.; Siegel, Nathan P.

    2017-02-28

    A method for splitting carbon dioxide via a two-step metal oxide thermochemical cycle by heating a metal oxide compound selected from an iron oxide material of the general formula A.sub.xFe.sub.3-xO.sub.4, where 0.ltoreq.x.ltoreq.1 and A is a metal selected from Mg, Cu, Zn, Ni, Co, and Mn, or a ceria oxide compound of the general formula M.sub.aCe.sub.bO.sub.c, where 0carbon dioxide, and heating to a temperature less than approximately 1400 C, thereby producing carbon monoxide gas and the original metal oxide compound.

  9. CARBON DIOXIDE AS A FEEDSTOCK.

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Growth responses of Melastoma malabathricum to elevated carbon dioxide and water regime

    Science.gov (United States)

    Nasir, Wan Nur Ain Mat; Ahmad, Wan Juliana Wan; Musa, Nor Lailatul Wahidah

    2016-11-01

    Elevated atmospheric CO2 has significant effects on plant growth depending on the species and the interaction between treatments given. In other words, the impacts vary among species, depending on differences in photosynthetic pathways, intrinsic growth rates and other properties. In this research we studied the effects of increased carbon dioxide concentration and water regimes on a shrub species, Melastoma malabathricum in a shade house at ambient CO2 and open roof greenhouse at elevated CO2. The factor of water stress was also included, in which for each CO2 treatment, the amount of water was given once or twice daily. The treatment of elevated CO2 was at 800 ppm, when the plants were exposed daily from 0900h until 1100h. The plant growth was monitored through their biomass, height and leaf area that were recorded fortnightly for six months. The results showed that the height of M. malabathricum stem in elevated CO2 was significantly higher than those in ambient CO2. Similarly, leaf area in the elevated CO2 showed a big difference with a value of 46.24 cm2 for elevated CO2 with twice watering, but only 17.94 cm2 for ambient CO2 with twice watering. Even for once watering, we can see the values of leaf area were higher with 32.06 cm2 for elevated and 24.35 cm2 in ambient CO2. The above ground and below ground biomass differed significantly between ambient and elevated CO2. Above ground biomass in ambient CO2 was higher than that in elevated CO2 with a percentage of 25.7%. In contrast, the below ground biomass in elevated CO2 was higher than that in ambient CO2 with a percentage of 17.4%. The results suggested that the increment of CO2 concentrations and water regime in the natural environment may influence the growth and ultimately the abundance and distribution of this shrub species in urban forest.

  11. Perspectives in the use of carbon dioxide

    Directory of Open Access Journals (Sweden)

    Aresta Michele

    1999-01-01

    Full Text Available The mitigation of carbon dioxide is one of the scientific and technological challenges of the 2000s. Among the technologies that are under assessment, the recovery of carbon dioxide from power plants or industrial flue gases plays a strategic role. Recovered carbon dioxide can be either disposed in natural fields or used. The availability of large amounts of carbon dioxide may open new routes to its utilisation in biological, chemical and innovative technological processes. In this paper, the potential of carbon dioxide utilisation in the short-, medium-term is reviewed.

  12. GEOLOGICAL STORAGE OF CARBON DIOXIDE

    Directory of Open Access Journals (Sweden)

    Iva Kolenković

    2014-07-01

    Full Text Available Carbon dioxide geological storage represents a key segment of the carbon capture and storage system (CCS expected to significantly contribute to the reduction of its emissions, primarily in the developed countries and in those that are currently being industrialised. This approach to make use of the subsurface is entirely new meaning that several aspects are still in research phase. The paper gives a summary of the most important recent results with a short overview the possibilities in the Republic of Croatia. One option is to construct underground carbon dioxide storage facilities in deep coal seams or salt caverns. Another would be to use the CO2 in enhanced oil and gas recovery projects relying on the retention of the carbon dioxide in the deep reservoir because a portion of the injected gas is not going be produced together with hydrocarbons. Finally, the greatest potential estimated lies in depleted hydrocarbon reservoirs with significantly reduced reservoir pressure, as well as in the large regional units - layers of deep saline aquifers that extend through almost all sedimentary basins (the paper is published in Croatian.

  13. 21 CFR 184.1240 - Carbon dioxide.

    Science.gov (United States)

    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. Carbon...

  14. Carbon Dioxide Mediates the Response to Temperature and Water Activity Levels in Aspergillus flavus during Infection of Maize Kernels

    Directory of Open Access Journals (Sweden)

    Matthew K. Gilbert

    2017-12-01

    Full Text Available Aspergillus flavus is a saprophytic fungus that may colonize several important crops, including cotton, maize, peanuts and tree nuts. Concomitant with A. flavus colonization is its potential to secrete mycotoxins, of which the most prominent is aflatoxin. Temperature, water activity (aw and carbon dioxide (CO2 are three environmental factors shown to influence the fungus-plant interaction, which are predicted to undergo significant changes in the next century. In this study, we used RNA sequencing to better understand the transcriptomic response of the fungus to aw, temperature, and elevated CO2 levels. We demonstrate that aflatoxin (AFB1 production on maize grain was altered by water availability, temperature and CO2. RNA-Sequencing data indicated that several genes, and in particular those involved in the biosynthesis of secondary metabolites, exhibit different responses to water availability or temperature stress depending on the atmospheric CO2 content. Other gene categories affected by CO2 levels alone (350 ppm vs. 1000 ppm at 30 °C/0.99 aw, included amino acid metabolism and folate biosynthesis. Finally, we identified two gene networks significantly influenced by changes in CO2 levels that contain several genes related to cellular replication and transcription. These results demonstrate that changes in atmospheric CO2 under climate change scenarios greatly influences the response of A. flavus to water and temperature when colonizing maize grain.

  15. A modified impulse-response representation of the global near-surface air temperature and atmospheric concentration response to carbon dioxide emissions

    Directory of Open Access Journals (Sweden)

    R. J. Millar

    2017-06-01

    Full Text Available Projections of the response to anthropogenic emission scenarios, evaluation of some greenhouse gas metrics, and estimates of the social cost of carbon often require a simple model that links emissions of carbon dioxide (CO2 to atmospheric concentrations and global temperature changes. An essential requirement of such a model is to reproduce typical global surface temperature and atmospheric CO2 responses displayed by more complex Earth system models (ESMs under a range of emission scenarios, as well as an ability to sample the range of ESM response in a transparent, accessible and reproducible form. Here we adapt the simple model of the Intergovernmental Panel on Climate Change 5th Assessment Report (IPCC AR5 to explicitly represent the state dependence of the CO2 airborne fraction. Our adapted model (FAIR reproduces the range of behaviour shown in full and intermediate complexity ESMs under several idealised carbon pulse and exponential concentration increase experiments. We find that the inclusion of a linear increase in 100-year integrated airborne fraction with cumulative carbon uptake and global temperature change substantially improves the representation of the response of the climate system to CO2 on a range of timescales and under a range of experimental designs.

  16. A modified impulse-response representation of the global near-surface air temperature and atmospheric concentration response to carbon dioxide emissions

    Science.gov (United States)

    Millar, Richard J.; Nicholls, Zebedee R.; Friedlingstein, Pierre; Allen, Myles R.

    2017-06-01

    Projections of the response to anthropogenic emission scenarios, evaluation of some greenhouse gas metrics, and estimates of the social cost of carbon often require a simple model that links emissions of carbon dioxide (CO2) to atmospheric concentrations and global temperature changes. An essential requirement of such a model is to reproduce typical global surface temperature and atmospheric CO2 responses displayed by more complex Earth system models (ESMs) under a range of emission scenarios, as well as an ability to sample the range of ESM response in a transparent, accessible and reproducible form. Here we adapt the simple model of the Intergovernmental Panel on Climate Change 5th Assessment Report (IPCC AR5) to explicitly represent the state dependence of the CO2 airborne fraction. Our adapted model (FAIR) reproduces the range of behaviour shown in full and intermediate complexity ESMs under several idealised carbon pulse and exponential concentration increase experiments. We find that the inclusion of a linear increase in 100-year integrated airborne fraction with cumulative carbon uptake and global temperature change substantially improves the representation of the response of the climate system to CO2 on a range of timescales and under a range of experimental designs.

  17. Carbon dioxide and climate impulse response functions for the computation of greenhouse gas metrics: a multi-model analysis

    Directory of Open Access Journals (Sweden)

    F. Joos

    2013-03-01

    Full Text Available The responses of carbon dioxide (CO2 and other climate variables to an emission pulse of CO2 into the atmosphere are often used to compute the Global Warming Potential (GWP and Global Temperature change Potential (GTP, to characterize the response timescales of Earth System models, and to build reduced-form models. In this carbon cycle-climate model intercomparison project, which spans the full model hierarchy, we quantify responses to emission pulses of different magnitudes injected under different conditions. The CO2 response shows the known rapid decline in the first few decades followed by a millennium-scale tail. For a 100 Gt-C emission pulse added to a constant CO2 concentration of 389 ppm, 25 ± 9% is still found in the atmosphere after 1000 yr; the ocean has absorbed 59 ± 12% and the land the remainder (16 ± 14%. The response in global mean surface air temperature is an increase by 0.20 ± 0.12 °C within the first twenty years; thereafter and until year 1000, temperature decreases only slightly, whereas ocean heat content and sea level continue to rise. Our best estimate for the Absolute Global Warming Potential, given by the time-integrated response in CO2 at year 100 multiplied by its radiative efficiency, is 92.5 × 10−15 yr W m−2 per kg-CO2. This value very likely (5 to 95% confidence lies within the range of (68 to 117 × 10−15 yr W m−2 per kg-CO2. Estimates for time-integrated response in CO2 published in the IPCC First, Second, and Fourth Assessment and our multi-model best estimate all agree within 15% during the first 100 yr. The integrated CO2 response, normalized by the pulse size, is lower for pre-industrial conditions, compared to present day, and lower for smaller pulses than larger pulses. In contrast, the response in temperature, sea level and ocean heat content is less sensitive to these choices. Although, choices in pulse size, background concentration, and model lead to uncertainties, the most important and

  18. Sonochemical reduction of carbon dioxide.

    Science.gov (United States)

    Harada, H

    1998-06-01

    Sonolysis of carbon dioxide dissolved in water was performed from a standpoint of reducing this material in atmosphere. During one hour of sonication, the amount of CO2 decreased to about half at 5 degrees C under CO2-Ar atmosphere. The decreasing rate for CO2 followed the order Ar > He > H2 > N2 and it was down with increasing temperature in the range of 5-45 degrees C. The most favorable concentration for reducing CO2 was 0.03 (mole fraction of CO2 in gas phase). This concentration in gas phase means an equal mixture of CO2 and Ar in water, because CO2 is more soluble than Ar. Since carbon dioxide dissolved in water would be partly ionized, the roles of ions on the sonolysis were also examined. Gaseous reaction products were CO, H2 and a small amount of O2. Carbon monoxide and hydrogen might be obtained from CO2 and H2O by sonolysis, respectively. Both gases are fuel and react each other to C1 compounds such as methanol, and so on. Therefore, irradiation of ultrasonic waves should be an important technique for reducing CO2.

  19. Nitrogen to phosphorus ratios of tree species in response to elevated carbon dioxide and nitrogen addition in subtropical forests.

    Science.gov (United States)

    Liu, Juxiu; Huang, Wenjuan; Zhou, Guoyi; Zhang, Deqiang; Liu, Shizhong; Li, Yiyong

    2013-01-01

    Increased atmospheric carbon dioxide (CO2 ) concentrations and nitrogen (N) deposition induced by human activities have greatly influenced the stoichiometry of N and phosphorus (P). We used model forest ecosystems in open-top chambers to study the effects of elevated CO2 (ca. 700 μmol mol(-1) ) alone and together with N addition (100 kg N ha(-1)  yr(-1) ) on N to P (N : P) ratios in leaves, stems and roots of five tree species, including four non-N2 fixers and one N2 fixer, in subtropical China from 2006 to 2009. Elevated CO2 decreased or had no effects on N : P ratios in plant tissues of tree species. N addition, especially under elevated CO2 , lowered N : P ratios in the N2 fixer, and this effect was significant in the stems and the roots. However, only one species of the non-N2 fixers showed significantly lower N : P ratios under N addition in 2009, and the others were not affected by N addition. The reductions of N : P ratios in response to elevated CO2 and N addition were mainly associated with the increases in P concentrations. Our results imply that elevated CO2 and N addition could facilitate tree species to mitigate P limitation by more strongly influencing P dynamics than N in the subtropical forests. © 2012 Blackwell Publishing Ltd.

  20. Yield, chemical composition and nutritional quality responses of carrot, radish and turnip to elevated atmospheric carbon dioxide.

    Science.gov (United States)

    Azam, Andaleeb; Khan, Ikhtiar; Mahmood, Abid; Hameed, Abdul

    2013-10-01

    Future concentration of carbon dioxide in the atmosphere is very important due to its apparent economic and environmental impact in terms of climate change. However, a compressive assessment of its effect on the nutritional and chemical characteristics of food crops has yet to be established. In the present study the impact of elevated atmospheric CO2 on the yield, chemical composition and nutritional quality of three root vegetables, carrot (Daucus carota L. cv. T-1-111), radish (Raphanus sativus L. cv. Mino) and turnip (Brassica rapa L. cv. Grabe) has been investigated. The yield of carrot, radish and turnip increased by 69, 139 and 72%, respectively, when grown under elevated CO2 conditions. Among the proximate composition, protein, vitamin C and fat contents decreased significantly for all the vegetables while sugar and fibre contents were increased. Response of the vegetables to elevated CO2 , in terms of elemental composition, was different with a significant decrease in many important minerals. Elevated CO2 decreased the amount of majority of the fatty acids and amino acids in these vegetables. It was observed that elevated CO2 increased the yield of root vegetables but many important nutritional parameters including protein, vitamin C, minerals, essential fatty acids and amino acids were decreased. © 2013 Society of Chemical Industry.

  1. Optimization for Dwarf Banana with Microwave Low Temperature Carbon Dioxide Flash Puffing Process by Response Surface Methodology and Factor Analysis

    Directory of Open Access Journals (Sweden)

    Li Bao-Yu

    2016-01-01

    Full Text Available A three factors quadratic regression rotation combination design was adopted to optimize the technical conditions of microwave low temperature carbon dioxide flash puffing (MLTCDFP process for dwarf banana in the single factor’s foundation. This paper analyzed the effect of puffing temperature, puffing pressure, vacuum drying temperature and the interaction of the three factors on color, crispness, and the effect of hardness and water content. Based on the experimental data, the quadratic regression model of four indexes was deduced, then variables were analyzed with response surface methodology (RSM. The weights of four evaluation indexes was determined by factor analysis. The regression square was obtained by the comprehensive score as follow: Y=0.955+0.109X1+0.16X3−0.09X12+0.015X22 −0.15X32−0.018X1X2−0.056X1X3+0.016X2X3(R2=0.837.Through factor analysis, the range of the optimal technical conditions of MLTCDFP for dwarf banana obtained. The result indicated the four indexes were affected significantly by the puffing temperature and vacuum drying temperature, and the interactions of the three factors did not affect the product obviously. The optimal technical parameters were as follows: puffing temperature 91~95°C, puffing pressure 0.11~0.19MPa, vacuum temperature 81~85°C.

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

    Science.gov (United States)

    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.

  3. Carbon dioxide reducing processes; Koldioxidreducerande processer

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, Fredrik

    1999-12-01

    This thesis discusses different technologies to reduce or eliminate the carbon dioxide emissions, when a fossil fuel is used for energy production. Emission reduction can be accomplished by separating the carbon dioxide for storage or reuse. There are three different ways of doing the separation. The carbon dioxide can be separated before the combustion, the process can be designed so that the carbon dioxide can be separated without any energy consumption and costly systems or the carbon dioxide can be separated from the flue gas stream. Two different concepts of separating the carbon dioxide from a combined cycle are compared, from the performance and the economical point of view, with a standard natural gas fired combined cycle where no attempts are made to reduce the carbon dioxide emissions. One concept is to use absorption technologies to separate the carbon dioxide from the flue gas stream. The other concept is based on a semi-closed gas turbine cycle using carbon dioxide as working fluid and combustion with pure oxygen, generated in an air-separating unit. The calculations show that the efficiency (power) drop is smaller for the first concept than for the second, 8.7 % points compared to 13.7 % points, when power is produced. When both heat and power are produced, the relation concerning the efficiency (power) remains. Regarding the overall efficiency (heat and power) the opposite relation is present. A possible carbon dioxide tax must exceed 0.21 SEK/kg CO{sub 2} for it to be profitable to separate carbon dioxide with any of these technologies.

  4. Carbon dioxide disposal in solid form

    Energy Technology Data Exchange (ETDEWEB)

    Lackner, K.S.; Butt, D.P.; Sharp, D.H. [Los Alamos National Lab., NM (United States); Wendt, C.H. [Auxon Corp., (United States)

    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.

  5. Robust optical carbon dioxide isotope analyzer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Isotopic analysis of carbon dioxide is an important tool for characterization of the exchange and transformation of carbon between the biosphere and the atmosphere....

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

    Energy Technology Data Exchange (ETDEWEB)

    Sepanski, R.J. [Tennessee Univ., Knoxville, TN (United States). 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. [Agricultural Research Service, Phoenix, AZ (United States); Lakatos, E.A. [Arizona Univ., Tucson, AZ (United States). Dept. of Soil and Water Science

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Sepanski, R.J. (Tennessee Univ., Knoxville, TN (United States). 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. (Agricultural Research Service, Phoenix, AZ (United States)); 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.

  8. Carbon dioxide: making the right connection

    African Journals Online (AJOL)

    Carbon dioxide has been used in anaesthesia since the late 1920s, principally to stimulate breathing after a period of hyperventilation in the era before routine use of capnography. The authors' tertiary academic hospital still has the infrastructure for pipeline delivery of carbon dioxide. A case is reported of accidental ...

  9. Carbon dioxide production in animal houses

    DEFF Research Database (Denmark)

    Pedersen, Søren; Blanes-Vidal, Victoria; Joergensen, H.

    2008-01-01

    This article deals with carbon dioxide production from farm animals; more specifically, it addresses the possibilities of using the measured carbon dioxide concentration in animal houses as basis for estimation of ventilation flow (as the ventilation flow is a key parameter of aerial emissions from...... animal houses). The investigations include measurements in respiration chambers and in animal houses, mainly for growing pigs and broilers. Over the last decade a fixed carbon dioxide production of 185 litres per hour per heat production unit, hpu (i.e. 1000 W of the total animal heat production at 20o......C) has often been used. The article shows that the carbon dioxide production per hpu increases with increasing respiration quotient. As the respiration quotient increases with body mass for growing animals, the carbon dioxide production per heat production unit also increases with increased body mass...

  10. The response of phytoplankton carbon and nitrogen processes to elevated carbon dioxide in the Point Reyes, CA upwelling

    Science.gov (United States)

    Dugdale, R. C.; Wilkerson, F. P.; Fuller, J. R.; Parker, A. E.; Marchi, A.

    2009-12-01

    Increased pCO2/increased ocean acidity has been observed in upwelling waters along the US west coast. Initial pCO2 concentrations in excess of 1000 µatm are significantly reduced within a few days as a result of phytoplankton primary production and transport. Experimental mesocosm experiments conducted in a Norwegian fjord showed that with elevated pCO2, carbon drawdown increased but with no effect on nutrient drawdown. Ratios of C:N drawdown exceeded the Redfield ratio, 6.6, while the ratio of particulate C:N ratio stayed constant. This apparent overconsumption of carbon appeared to be mostly shunted into dissolved organic carbon (DOC). We address the question of C:N drawdown ratios and the possibility of carbon overconsumption in upwelled waters along the Marin coast, from the Golden Gate up to Point Reyes, CA. Experimental enclosures were filled with recently upwelled water with elevated pCO2 and then sampled daily over 5 days for concentrations of dissolved inorganic carbon, DOC, nutrients, POC and PON, and chlorophyll, as well as phytoplankton species composition, and phytoplankton uptake rates of nitrate, ammonium and carbon using isotopic tracers.

  11. Encapsulated liquid sorbents for carbon dioxide capture.

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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. Electrocatalysts for carbon dioxide conversion

    Science.gov (United States)

    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.

  14. On measuring the response of mesophyll conductance to carbon dioxide with the variable J method.

    Science.gov (United States)

    Gilbert, Matthew Edmund; Pou, Alícia; Zwieniecki, Maciej Andrzej; Holbrook, N Michele

    2012-01-01

    The response of mesophyll conductance to CO(2) (g(m)) to environmental variation is a challenging parameter to measure with current methods. The 'variable J' technique, used in the majority of studies of g(m), assumes a one-to-one relationship between photosystem II (PSII) fluorescence and photosynthesis under non-photorespiratory conditions. When calibrating this relationship for Populus trichocarpa, it was found that calibration relationships produced using variation in light and CO(2) were not equivalent, and in all cases the relationships were non-linear-something not accounted for in previous studies. Detailed analyses were performed of whether different calibration procedures affect the observed g(m) response to CO(2). Past linear and assumed calibration methods resulted in systematic biases in the fluorescence estimates of electron transport. A sensitivity analysis on modelled data (where g(m) was held constant) demonstrated that biases in the estimation of electron transport as small as 2% (∼0.5 μmol m(-2) s(-1)) resulted in apparent changes in the relationship of g(m) to CO(2) of similar shape and magnitude to those observed with past calibration techniques. This sensitivity to biases introduced during calibrations leads to results where g(m) artefactually decreases with CO(2), assuming that g(m) is constant; if g(m) responds to CO(2), then biases associated with past calibration methods would lead to overestimates of the slope of the relationship. Non-linear calibrations were evaluated; these removed the bias present in past calibrations, but the method remained sensitive to measurement errors. Thus measurement errors, calibration non-linearities leading to bias, and the sensitivity of variable J g(m) hinders its use under conditions of varying CO(2) or light.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2015-09-18

    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. 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. 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. Parasympathetic activity dominated in cardiac autonomic modulation, and heart rate and blood pressure increased significantly after high intensity exercise in C3.

  18. Fixation of carbon dioxide into dimethyl carbonate over ...

    Science.gov (United States)

    A titanium-based zeolitic thiophene-benzimidazolate framework has been designed for the direct synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide. The developed catalyst activates carbon dioxide and delivers over 16% yield of DMC without the use of any dehydrating agent or requirement for azeotropic distillation. Prepared for submission to Nature Scientific reports.

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

    Science.gov (United States)

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

    2014-10-16

    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.

  20. Changes in Nutritional Metabolites of Young Ginger (Zingiber officinale Roscoe in Response to Elevated Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Ali Ghasemzadeh

    2014-10-01

    Full Text Available 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.

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

    DEFF Research Database (Denmark)

    Colombo, Stefano; Brisander, Magnus; Haglöf, Jakob

    2015-01-01

    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...... 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...

  2. Carbon dioxide capture process with regenerable sorbents

    Science.gov (United States)

    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.

  3. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    Energy Technology Data Exchange (ETDEWEB)

    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

  4. High performance hydrophobic solvent, carbon dioxide capture

    Science.gov (United States)

    Nulwala, Hunaid; Luebke, David

    2017-05-09

    Methods and compositions useful, for example, for physical solvent carbon capture. A method comprising: contacting at least one first composition comprising carbon dioxide with at least one second composition to at least partially dissolve the carbon dioxide of the first composition in the second composition, wherein the second composition comprises at least one siloxane compound which is covalently modified with at least one non-siloxane group comprising at least one heteroatom. Polydimethylsiloxane (PDMS) materials and ethylene-glycol based materials have high carbon dioxide solubility but suffer from various problems. PDMS is hydrophobic but suffers from low selectivity. Ethylene-glycol based systems have good solubility and selectivity, but suffer from high affinity to water. Solvents were developed which keep the desired combinations of properties, and result in a simplified, overall process for carbon dioxide removal from a mixed gas stream.

  5. 21 CFR 868.1400 - Carbon dioxide gas analyzer.

    Science.gov (United States)

    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 dioxide...

  6. 46 CFR 169.732 - Carbon dioxide alarm.

    Science.gov (United States)

    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.” ...

  7. 46 CFR 78.47-9 - Carbon dioxide alarm.

    Science.gov (United States)

    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) ...

  8. 46 CFR 97.37-9 - Carbon dioxide alarm.

    Science.gov (United States)

    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 BEING...

  9. 46 CFR 76.15-20 - Carbon dioxide storage.

    Science.gov (United States)

    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 the...

  10. 46 CFR 108.627 - Carbon dioxide alarm.

    Science.gov (United States)

    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 to...

  11. 46 CFR 95.15-20 - Carbon dioxide storage.

    Science.gov (United States)

    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 space...

  12. 46 CFR 196.37-9 - Carbon dioxide alarm.

    Science.gov (United States)

    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 BEING...

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

    Science.gov (United States)

    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. Published by Oxford University Press on behalf of Entomological Society of America 2015. This work is written by US Government employees and is in the public domain in the US.

  14. Reactive Capture of Carbon Dioxide Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this Phase I SBIR, Reactive Innovations, LLC (RIL) proposes to develop a compact and lightweight electrochemical to capture carbon dioxide in the martian...

  15. Carbon Dioxide Collection and Pressurization Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Reactive Innovations, LLC, proposes a Phase I SBIR program to develop a compact and lightweight electrochemical reactor to separate and pressurize carbon dioxide...

  16. Behavioral responses of Arctica islandica (Bivalvia: Arcticidae) to simulated leakages of carbon dioxide from sub-sea geological storage

    Energy Technology Data Exchange (ETDEWEB)

    Bamber, Shaw D., E-mail: shaw.bamber@iris.no; Westerlund, Stig, E-mail: sw@iris.no

    2016-11-15

    Highlights: • Valve pumping activity in A. islandica significantly increased at pH 6.2 seawater. • Changes in valve movements were not related to attempted burrowing activities. • Valve activity returned to control levels after 5 days of continuous exposure. • A. islandica tolerate pH reductions likely to follow leakage of sub-sea stored CO{sub 2}. - Abstract: Sub-sea geological storage of carbon dioxide (CO{sub 2}) provides a viable option for the Carbon Capture and Storage (CCS) approach for reducing atmospheric emissions of this greenhouse gas. Although generally considered to offer a low risk of major leakage, it remains relevant to establish the possible consequences for marine organisms that live in or on sediments overlying these storage areas if such an event may occur. The present study has used a series of laboratory exposures and behavioral bioassays to establish the sensitivity of Arctica islandica to simulated leakages of CO{sub 2}. This long-lived bivalve mollusc is widely distributed throughout the North Sea, an area where geological storage is currently taking place and where there are plans to expand this operation significantly. A recently published model has predicted a maximum drop of 1.9 pH units in seawater at the point source of a substantial escape of CO{sub 2} from sub-sea geological storage in this region. Valve movements of A. islandica exposed to reduced pH seawater were recorded continuously using Hall effect proximity sensors. Valve movement regulation is important for optimising the flow of water over the gills, which supplies food and facilitates respiration. A stepwise reduction in seawater pH showed an initial increase in both the rate and extent of valve movements in the majority of individuals tested when pH fell to 6.2 units. Exposing A. islandica to pH 6.2 seawater continuously for seven days resulted in a clear increase in valve movements during the first 40 h of exposure, followed by a gradual reduction in activity

  17. Gas-exchange, water use efficiency and yield responses of elite potato (Solanum tuberosum L.) cultivars to changes in atmospheric carbon dioxide concentration, temperature and relative humidity

    DEFF Research Database (Denmark)

    Kaminski, Kacper Piotr; Sørensen, Kirsten Kørup; Nielsen, Kåre Lehmann

    2014-01-01

    In spite of the agricultural importance of potato (Solanum tuberosum L.), most plant physiology studies have not accounted for the effect of the interaction between elevated carbon dioxide concentration ([CO2]) and other consequences of climate change on WUE. In 2010, a first controlled environment...... and stomatal conductance (high temperature) or a combination of those two responses (moderate temperature). The results signify that beneficial effects of potato plant cultivation at elevated [CO2] comprise increased WUE at various temperature levels, but due to acclimation of photosynthesis the increase...

  18. Carbon dioxide detection in adult Odonata.

    Science.gov (United States)

    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. Copyright © 2016 Elsevier GmbH. All rights reserved.

  19. Temporal biomass dynamics of an Arctic plankton bloom in response to increasing levels of atmospheric carbon dioxide

    Directory of Open Access Journals (Sweden)

    K. G. Schulz

    2013-01-01

    Full Text Available Ocean acidification and carbonation, driven by anthropogenic emissions of carbon dioxide (CO2, have been shown to affect a variety of marine organisms and are likely to change ecosystem functioning. High latitudes, especially the Arctic, will be the first to encounter profound changes in carbonate chemistry speciation at a large scale, namely the under-saturation of surface waters with respect to aragonite, a calcium carbonate polymorph produced by several organisms in this region. During a CO2 perturbation study in Kongsfjorden on the west coast of Spitsbergen (Norway, in the framework of the EU-funded project EPOCA, the temporal dynamics of a plankton bloom was followed in nine mesocosms, manipulated for CO2 levels ranging initially from about 185 to 1420 μatm. Dissolved inorganic nutrients were added halfway through the experiment. Autotrophic biomass, as identified by chlorophyll a standing stocks (Chl a, peaked three times in all mesocosms. However, while absolute Chl a concentrations were similar in all mesocosms during the first phase of the experiment, higher autotrophic biomass was measured as high in comparison to low CO2 during the second phase, right after dissolved inorganic nutrient addition. This trend then reversed in the third phase. There were several statistically significant CO2 effects on a variety of parameters measured in certain phases, such as nutrient utilization, standing stocks of particulate organic matter, and phytoplankton species composition. Interestingly, CO2 effects developed slowly but steadily, becoming more and more statistically significant with time. The observed CO2-related shifts in nutrient flow into different phytoplankton groups (mainly dinoflagellates, prasinophytes and haptophytes could have consequences for future organic matter flow to higher trophic levels and export production, with consequences

  20. Turning carbon dioxide into fuel.

    Science.gov (United States)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, L E [ed.

    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)

  2. Apparatus for extracting and sequestering carbon dioxide

    Science.gov (United States)

    Rau, Gregory H [Castro Valley, CA; Caldeira, Kenneth G [Livermore, CA

    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.

  3. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    Energy Technology Data Exchange (ETDEWEB)

    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

  4. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    Energy Technology Data Exchange (ETDEWEB)

    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

  5. Colorimetric and refractometric measurements of carbon dioxide

    Science.gov (United States)

    Jesus Gouveia, C.; Markovics, A.; Baptista, J. M.; Kovács, B.; Jorge, P. A. S.

    2011-05-01

    In this work, a polymeric sensitive layer based on the acid-base equilibrium of phenol and of its derivative p-nitro-phenol is presented for carbon dioxide measurements. Thin films casted on glass slides were tested, using a LED source (λc at 410 nm) and an Ocean Optics USB4000 spectrometer, in the 0% to 15.25% CO2 concentrations range, showing a 40% maximum transmittance variation with a 51s response time and a 0.15% resolution. Preliminary results indicate that CO2also induces refractive index changes in the sensitive layer. Using a fiber based interferometric setup, a CO2 dependent refractive index change of ~0.045 RIU was observed, in the 0%-90% CO2 concentration range.

  6. Inter-comparison of two high-accuracy fast-response spectroscopic sensors of carbon dioxide: a case study

    Directory of Open Access Journals (Sweden)

    B. A. Flowers

    2012-05-01

    Full Text Available Tunable diode laser absorption (TDL and cavity ring-down spectroscopic (CRDS sensors for atmospheric carbon dioxide were co-deployed during summer and fall of 2010 in field and laboratory conditions at Los Alamos National Laboratory. Both sensors were characterized for accuracy and precision for ambient carbon dioxide measurements at ground level and compared using both laboratory and ambient field data. After post-processing that included water vapor correction and calibration to WMO reference standards, overall mean [12C16O2] = 392.05 ± 8.92 ppm and [12C16O2] = 392.22 ± 9.05 ppm were observed between 29 July and 16 August 2010. The mean difference between the CRDS and TDL data for 12CO2 was 0.04 ± 1.80 ppm (±1σ in 60 s for ambient field data, demonstrating the sensors meet the WMO/IAEA compatibility standard. The observations show over the 19-day period the [CO2]CRDS'/[CO2]TDL ratio exhibits a Gaussian distribution centered at x0 = 1.003 ± 3.38 × 10−5 (±1σ, indicating the ratio is dominated by random noise as opposed to a bias in the output of either sensor. The CRDS sensor is capable of measuring [12C16O2] to a precision of 23 ppb in 1 min and decreases to 6.5 ppb in 58 min. At one and 58-min, the TDL exhibits precisions of 29 ppb and 53 ppb. The CRDS is compact, fast, and stable; the TDL is larger and requires frequent calibrations to maintain its precision. The sensors also exhibit consistent hourly averaged diurnal values underscoring the interplay of biological, anthropogenic, and transport processes regulating CO2 at the site.

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

    Science.gov (United States)

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

    2014-01-07

    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.

  8. Systematic framework for carbon dioxide capture and utilization processes to reduce the global carbon dioxide emissions

    DEFF Research Database (Denmark)

    Frauzem, Rebecca; Plaza, Cristina Calvera; Gani, Rafiqul

    the two approaches that are currently being investigated, carbon capture and storage (CCS) and carbon capture and utilization (CCU) [1] to address this issue, the later approach is more promising as it reuses captured carbon dioxide, as a fuel, reactant, solvent, and others, to produce valuable products......In the year 2013, 9.5 billion metric tons of carbon dioxide gas was emitted into the air, and each year this amount is increasing [1]. Carbon dioxide emissions are of particular concern as they represent 80% of greenhouse gas emissions and therefore are a large contributor to global warming. Among....... There is not only a need for technologies for capture and utilization, via conversion, but also there are numerous questions that need to be resolved. For example, which higher value chemicals can be produced, what are their current demands and costs of production, and, how much of the captured carbon dioxide would...

  9. Electron irradiation of carbon dioxide-carbon disulphide ice analog ...

    Indian Academy of Sciences (India)

    Upon electron irradiation the chemical composition was found to have altered and the new products from irradiation were found to be carbonyl sulphide (OCS), sulphur dioxide (SO2), ozone (O3), carbon trioxide (CO3), sulphur trioxide (SO3), carbon subsulphide (C3S2) and carbon monoxide (CO). Results obtained confirm ...

  10. Carbon dioxide fluxes from a degraded woodland in West Africa and their responses to main environmental factors.

    Science.gov (United States)

    Ago, Expedit Evariste; Serça, Dominique; Agbossou, Euloge Kossi; Galle, Sylvie; Aubinet, Marc

    2015-12-01

    In West Africa, natural ecosystems such as woodlands are the main source for energy, building poles and livestock fodder. They probably behave like net carbon sinks, but there are only few studies focusing on their carbon exchange with the atmosphere. Here, we have analyzed CO2 fluxes measured for 17 months by an eddy-covariance system over a degraded woodland in northern Benin. Specially, temporal evolution of the fluxes and their relationships with the main environmental factors were investigated between the seasons. This study shows a clear response of CO2 absorption to photosynthetic photon flux density (Qp), but it varies according to the seasons. After a significant and long dry period, the ecosystem respiration (R) has increased immediately to the first significant rains. No clear dependency of ecosystem respiration on temperature has been observed. The degraded woodlands are probably the "carbon neutral" at the annual scale. The net ecosystem exchange (NEE) was negative during wet season and positive during dry season, and its annual accumulation was equal to +29 ± 16 g C m-2. The ecosystem appears to be more efficient in the morning and during the wet season than in the afternoon and during the dry season. This study shows diurnal and seasonal contrasted variations in the CO2 fluxes in relation to the alternation between dry and wet seasons. The Nangatchori site is close to the equilibrium state according to its carbon exchanges with the atmosphere. The length of the observation period was too short to justify the hypothesis about the "carbon neutrality" of the degraded woodlands at the annual scale in West Africa. Besides, the annual net ecosystem exchange depends on the intensity of disturbances due to the site management system. Further research works are needed to define a woodland management policy that might keep these ecosystems as carbon sinks.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wilkinson, M. [Univ. of Essex, Colchester (United Kingdom)]|[Writtle Coll. (United Kingdom)

    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.

  12. Carbon dioxide and water vapour characteristics on the west coast ...

    Indian Academy of Sciences (India)

    Carbon dioxide and water vapour in the atmo- sphere are considered as the green-house gases and responsible for the global warming, hence much attention has been given to its measurement and analysis (Jones et al. 1978; Jones and Smith 1977;. Leuning et al. 1982; Ohtaki and Matsui 1982;. Ohtaki 1985).

  13. Measurements of carbon dioxide and heat fluxes during monsoon ...

    Indian Academy of Sciences (India)

    An increase in carbon dioxide (CO2) concentrations in the atmosphere due to anthropogenic activities is responsible for global warming and hence in recent years, CO2 measurement network has expanded globally. In the monsoon season (July–September) of year 2011, we carried out measurements of CO2 and water ...

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

    Science.gov (United States)

    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.

  15. Tourism Transport, Technology, and Carbon Dioxide Emissions

    NARCIS (Netherlands)

    Peeters, P.M.

    2010-01-01

    Technological development from horse-drawn carriages to the new Airbus A380 has led to a remarkable increase in both the capacity and speed of tourist travel. This development has an endogenous systemic cause and will continue to increase carbon dioxide emissions/energy consumption if left

  16. Carbon dioxide (CO2) utilizing strain database

    African Journals Online (AJOL)

    Jane

    2011-10-17

    Oct 17, 2011 ... Culling of excess carbon dioxide from our environment is one of the major challenges to scientific communities. Many physical, chemical and biological methods have been practiced to overcome this problem. The biological means of CO2 fixation using various microorganisms is gaining importance.

  17. integrated vertical photobioreactor system for carbon dioxide

    African Journals Online (AJOL)

    Astri Nugroho

    2013-07-02

    Jul 2, 2013 ... Abstract. A vertical photobioreactor containing the microalgae Scenedesmus obliquus is a highly efficient system for converting carbon dioxide (CO2) into biomass. The use of photobioreactor for CO2 mitigation has been explored using microalgae as photosynthetic microorganism. The growth rate (μ, h-1) ...

  18. Carbon dioxide emissions from Indian monsoonal estuaries

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; Viswanadham, R.; Rao, G.D.; Prasad, V.R.; Kumar, B.S.K.; Naidu, S.A.; Kumar, N.A.; Rao, D.B.; Sridevi, T.; Krishna, M.S.; Reddy, N.P.C.; Sadhuram, Y.; Murty, T.V.R.

    estuarine system, the Pearl River Estuary, China. J. Geophys. Res., 114, G03013, doi: 10.1029/2008JG000905. Hunt, C.W., J.E. Salisbury, D. Vandemark, and W. McGillis (2010). Contrasting carbon dioxide inputs and exchange in three adjacent New England...

  19. Diffusion of carbon dioxide (1); eicosane (2)

    Science.gov (United States)

    Winkelmann, J.

    This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Börnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) carbon dioxide; (2) eicosane

  20. Heat transfer coefficient for boiling carbon dioxide

    DEFF Research Database (Denmark)

    Knudsen, Hans Jørgen Høgaard; Jensen, Per Henrik

    1998-01-01

    Heat transfer coefficient and pressure drop for boiling carbon dioxide (R744) flowing in a horizontal pipe has been measured. The calculated heat transfer coeeficient has been compared with the Chart correlation of Shah. The Chart Correlation predits too low heat transfer coefficient but the ratio...

  1. Integrated Vertical Photobioreactor System for Carbon Dioxide ...

    African Journals Online (AJOL)

    A vertical photobioreactor containing the microalgae Scenedesmus obliquus is a highly efficient system for converting carbon dioxide (CO2) into biomass. The use of photobioreactor for CO2 mitigation has been explored using microalgae as photosynthetic microorganism. The growth rate (m, h-1) were 0.03; 0.13; 0.20; 0.09 ...

  2. Carbon dioxide capture and air quality

    NARCIS (Netherlands)

    Horssen, A. van; Ramirez, C.A.; Harmelen, T. van; Koornneef, J.

    2011-01-01

    Carbon dioxide (CO2) is one of the most important greenhouse gases (GHG). The most dominant source of anthropogenic CO2 contributing to the rise in atmospheric concentration since the industrial revolution is the combustion of fossil fuels. These emissions are expected to result in global climate

  3. Carbon dioxide in European coastal waters

    NARCIS (Netherlands)

    Borges, A.V.; Schiettecatte, L.-S.; Abril, G.; Delille, B.; Gazeau, F.P.H.

    2006-01-01

    We compiled from literature annually integrated air–water fluxes of carbon dioxide (CO2) computed from field measurements, in 20 coastal European environments that were gathered into 3 main ecosystems: inner estuaries, upwelling continental shelves and non-upwelling continental shelves. The

  4. Catalyst cartridge for carbon dioxide reduction unit

    Science.gov (United States)

    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.

  5. Metabolic effects of Carbon Dioxide (CO 2 ) insufflation during ...

    African Journals Online (AJOL)

    Metabolic effects of Carbon Dioxide (CO 2 ) insufflation during laparoscopic surgery: changes in pH, arterial partial Pressure of Carbon Dioxide (PaCo 2 ) and End Tidal Carbon Dioxide (EtCO ... EtCO2 is still a good non-invasive monitor for estimation of PaCO2 during low tidal volume ventilation during pneumoperitoneum.

  6. Studies on carbon dioxide system in central Arabian sea

    Digital Repository Service at National Institute of Oceanography (India)

    AnilKumar, N.; Singbal, S.Y.S.

    Data on pH and total alkalinity have been utilised in the study of carbon dioxide and its species in Central Arabian Sea Total carbon dioxide and partial pressure of carbon dioxide remain fairly constant in the upper layers but increase...

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

    Science.gov (United States)

    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, refrigerated liquid must comply with the following special requirements: (1) All plates for tank, manway nozzle...

  8. 40 CFR 90.320 - Carbon dioxide analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... operation. Adjust the analyzer to optimize performance. (2) Zero the carbon dioxide analyzer with either... 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...

  9. 40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... optimize performance. (b) Zero the carbon dioxide analyzer with either zero-grade air or zero-grade... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Complete Heavy-Duty Vehicles; Test Procedures § 86.124-78 Carbon dioxide analyzer calibration. Prior to its...

  10. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... instrument start-up and operation. Adjust the analyzer to optimize performance. (2) Zero the carbon dioxide... 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...

  11. 40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... performance. (b) Zero the carbon dioxide analyzer with either zero-grade air or zero-grade nitrogen. (c... 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...

  12. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Science.gov (United States)

    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; except...

  13. 27 CFR 26.222 - Still wines containing carbon dioxide.

    Science.gov (United States)

    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 wine...

  14. 27 CFR 24.319 - Carbon dioxide record.

    Science.gov (United States)

    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 to...

  15. 46 CFR 169.565 - Fixed carbon dioxide system.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 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 of...

  16. Modeling of the fixed - bed adsorption of carbon dioxide and a carbon dioxide - nitrogen mixture on zeolite 13X

    OpenAIRE

    Dantas,T. L. P; Luna,F. M. T; Silva Jr.,I. J.; Torres,A. E. B.; Azevedo, D. C. S.; Rodrigues,A.E.; Moreira,R.F.P.M.

    2011-01-01

    In this study, the fixed - bed adsorption of carbon dioxide and a carbon dioxide - nitrogen mixture on zeolite 13X was investigated. The adsorption equilibrium and breakthrough curves were determined at different temperatures - 301 - 306 K, 323 K, 373 K and 423 K. A model based on the LDF approximation for the mass transfer, considering the energy and momentum balances, was used to describe the adsorption kinetics of carbon dioxide and a carbon dioxide - nitrogen mixture. The model acceptably...

  17. Electron irradiation of carbon dioxide-carbon disulphide ice analog ...

    Indian Academy of Sciences (India)

    Abstract. Carbon dioxide (CO2) and carbon disulphide (CS2) molecular ice mixture was prepared under low temperature (85 K) astrochemical conditions. The icy mixture irradiated with keV electrons simulates the irradiation environment experienced by icy satellites and Interstellar Icy Mantles (IIM). Upon electron irradi-.

  18. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Science.gov (United States)

    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. (b...

  19. Photosynthetic responses of forest understory tree species to long-term exposure to elevated carbon dioxide concentration at the Duke Forest FACE experiment

    Energy Technology Data Exchange (ETDEWEB)

    Springer, C.J. [West Virginia Univ., Morgantown, WV (United States); Thomas, R.B. [Kansas Univ., Lawrence, KS (United States). Dept. of Ecology and Evolutionary Biology

    2007-01-15

    Tree species growing within the forest understory contribute to the overall carbon balance of forest ecosystems in addition to representing many of the species that occur in the overstory of mature ecosystems. This article described a 7 year study investigating the responses of forest understory tree species to increasing concentrations of atmospheric carbon dioxide (CO{sub 2}). The study examined the photosynthetic responses of Acer rubrum L., Carya glabra Mill., Cercis Canadensis L., and Liquidambar styraciflua L. during their seventh year of exposure to elevated CO{sub 2} at the Duke Forest Free Air Carbon Enrichment (FACE) experiment to determine whether photosynthetic down-regulation had occurred, as well as to determine whether the enhancement of photosynthesis observed during the first year of exposure to elevated CO{sub 2} was sustained. The study was conducted to test a previous hypothesis that significant photosynthetic down-regulation would be observed after 7 years of exposure to elevated CO{sub 2}. Photosynthetic CO{sub 2} response and light response curves were measured, as well as chlorophyll fluorescence, chlorophyll concentration and foliar nitrogen (N). Results showed that exposure to elevated CO{sub 2} increased photosynthesis in all species measured after 7 years of treatment. The greatest photosynthetic increase was observed near saturating irradiances. In all species, elevated CO{sub 2} increased electron transport efficiency but did not significantly alter carboxylation efficiency. Quantum yield as estimated by light curves, chlorophyll concentration, and foliar N concentrations was unaffected by elevated CO{sub 2}. It was concluded that there was scant evidence of progressive N limitation of leaf-level processes in the understory species after 7 years of exposure to elevated CO{sub 2} in the experiment. 42 refs., 2 tabs., 4 figs.

  20. Augmentation of humoral and cellular immunity in response to Tetanus and Diphtheria toxoids by supercritical carbon dioxide extracts of Hippophae rhamnoides L. leaves.

    Science.gov (United States)

    Jayashankar, Bindhya; Singh, Divya; Tanwar, Himanshi; Mishra, K P; Murthy, Swetha; Chanda, Sudipta; Mishra, Jigni; Tulswani, R; Misra, K; Singh, S B; Ganju, Lilly

    2017-03-01

    Hippophae rhamnoides L. commonly known as Seabuckthorn (SBT), a wild shrub of family Elaegnacea, has extensively used for treating various ailments like skin diseases, jaundice, asthma, lung troubles. SBT leaves have been reported to possess several pharmacological properties including immunomodulatory, antioxidant, anti-inflammatory, antimicrobial and tissue regeneration etc. The present study was undertaken to evaluate the adjuvant property of supercritical carbon dioxide extracts (SCEs 300ET and 350ET) of SBT leaves in balb/c mice immunized with Tetanus and Diphtheria toxoids. The dynamic changes in the immune response were measured in terms of humoral and cell-mediated immune responses. We have seen the effect of SCEs on immunoglobulin subtypes and secondary immune response generation. In addition, the effect of SCEs on antigen specific cellular immunity was evaluated. Our results show that SCEs 300ET and 350ET significantly enhanced antibody titers in response to both TT and DT antigens. The secondary immune response generated was significantly increased in case of TT immunized animals. SCEs also enhanced cytokine levels (IFN-γ, IL-4, TNF-α and IL-1β) and increased lymphoproliferation. Besides, both SCEs did not show any toxic effects. Therefore, the study suggests that SCEs are safe and have potent immunostimulatory activity and hence, seems to be a promising balanced Th1 and Th2 directing immunological adjuvant for various veterinary as well as human vaccines. Copyright © 2017. Published by Elsevier B.V.

  1. Monitoring carbon dioxide in mechanically ventilated patients during hyperbaric treatment

    DEFF Research Database (Denmark)

    Bjerregård, Asger; Jansen, Erik

    2012-01-01

    Measurement of the arterial carbon dioxide (P(a)CO(2)) is an established part of the monitoring of mechanically ventilated patients. Other ways to get information about carbon dioxide in the patient are measurement of end-tidal carbon dioxide (P(ET)CO(2)) and transcutaneous carbon dioxide (PTCCO2......). Carbon dioxide in the blood and cerebral tissue has great influence on vasoactivity and thereby blood volume of the brain. We have found no studies on the correlation between P(ET)CO(2) or P(TC)CO(2), and P(a)CO(2) during hyperbaric oxygen therapy (HBOT)....

  2. Energy efficient solvent regeneration process for carbon dioxide capture

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Shaojun; Meyer, Howard S.; Li, Shiguang

    2018-02-27

    A process for removing carbon dioxide from a carbon dioxide-loaded solvent uses two stages of flash apparatus. Carbon dioxide is flashed from the solvent at a higher temperature and pressure in the first stage, and a lower temperature and pressure in the second stage, and is fed to a multi-stage compression train for high pressure liquefaction. Because some of the carbon dioxide fed to the compression train is already under pressure, less energy is required to further compress the carbon dioxide to a liquid state, compared to conventional processes.

  3. Materials for carbon dioxide separation

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qingqing

    2014-10-01

    The CO{sub 2} adsorption capacities at room temperature have been investigated by comparing carbon nanotubes, fullerene, graphenes, graphite and granular activated carbons. It turned out that the amount of the micropore surface area was dominating the CO{sub 2} adsorption ability. Another promising class of materials for CO{sub 2} capture and separation are CaO derived from the eggshells. Two aspects were studied in present work: a new hybrid materials synthesized by doping the CaTiO{sub 3} and the relationship between physisorption and chemisorption properties of CaO-based materials.

  4. Recycling technology of emitted carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Arakawa, Hironori [National Inst. of Materials and Chemical Research (NIMC), Ibaraki (Japan)

    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.

  5. Carbon Dioxide in Arable Soil Profiles

    DEFF Research Database (Denmark)

    Chirinda, Ngoni; Plauborg, Finn; Heckrath, Goswin Johann

    2014-01-01

    Carbon dioxide (CO2) concentrations in arable soil profiles are influenced by autotrophic and heterotrophic respiration as well as soil physical properties that regulate gas transport. Whereas different methods have been used to assess dynamics of soil CO2 concentrations, our understanding...... on the comparability of results obtained using different methods is limited. We therefore aimed to compare the dynamics in soil CO2 concentrations obtained from an automated system (GMP343 sensors) to those from a manually operated measurement system (i.e., soil gas sampled using stainless steel needles and rods......). In a winter wheat field in Denmark, soil CO2 concentrations were measured from 29 November 2011 to 14 June 2012 at upslope and footslope positions of a short catena (25 m). Carbon dioxide was measured at 20 and 40 cm soil depths (i.e., within and below the nominal plough layer) using the two measurement...

  6. Dye solubility in supercritical carbon dioxide fluid

    Directory of Open Access Journals (Sweden)

    Yan Jun

    2015-01-01

    Full Text Available Supercritical carbon dioxide fluid is an alternative solvent for the water of the traditional dyeing. The solubility of dyestuff affects greatly the dyeing process. A theoretical model for predicting the dye solubility is proposed and verified experimentally. The paper concludes that the pressure has a greater impact on the dyestuff solubility than temperature, and an optimal dyeing condition is suggested for the highest distribution coefficient of dyestuff.

  7. Climate retainment in carbon dioxide incubators

    Directory of Open Access Journals (Sweden)

    Schuh Matthias B.

    2016-09-01

    Full Text Available Ensuring optimal climate conditions during cultivation is essential for successful and reproducible cell culture based investigation. Being the gold standard, carbon dioxide incubators fulfill this demand in various geometries and sizes to suit diverse cultivation applications. A door opening results in a climate breakdown followed by a restoration period during which optimal conditions cannot be guaranteed. The following paper investigates the influence of incubator door design to optimize climate retainment during the above mentioned event.

  8. Carbon dioxide embolism during laparoscopic sleeve gastrectomy

    Directory of Open Access Journals (Sweden)

    Amir Abu Zikry

    2011-01-01

    Full Text Available 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 CO 2 at high flows through upper left quadrant of the abdomen, she had precipitous fall of end-tidal CO 2 and SaO 2 % 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.

  9. Carbon dioxide in Arctic and subarctic regions

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Carbon dioxide makes heat therapy work

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Electrocatalytic process for carbon dioxide conversion

    Energy Technology Data Exchange (ETDEWEB)

    Masel, Richard I.; Salehi-Khojin, Amin; Kutz, Robert

    2017-11-14

    An electrocatalytic process for carbon dioxide conversion includes combining a Catalytically Active Element and a Helper Polymer in the presence of carbon dioxide, allowing a reaction to proceed to produce a reaction product, and applying electrical energy to said reaction to achieve electrochemical conversion of said carbon dioxide reactant to said reaction product. The Catalytically Active Element can be a metal in the form of supported or unsupported particles or flakes with an average size between 0.6 nm and 100 nm. The reaction products comprise at least one of 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, (COO.sup.-).sub.2, and CF.sub.3COOH.

  12. Net ecosystem exchange of carbon dioxide and evapotranspiration response of a high elevation Rocky Mountain (Wyoming, USA) forest to a bark beetle epidemic

    Science.gov (United States)

    Frank, J. M.; Massman, W. J.; Ewers, B. E.

    2011-12-01

    Bark beetle epidemics have caused major disturbance in the forests of western North America where significant tree mortality alters the balance of ecosystem photosynthesis, carbon balance, and water exchange. In this study we investigate the change in the growing-season light-response of net ecosystem exchange of carbon dioxide (NEE) and evapotranspiration (ET) in a high elevation Rocky Mountain forest over the three years preceding and three years following a bark beetle outbreak. The GLEES AmeriFlux site (southeastern Wyoming, USA) is located in a high elevation subalpine forest dominated by Engelmann spruce (Picea engelmannii) and subalpine fir (Abies lasiocarpa) and recently experienced an epidemic of spruce beetle (Dendroctonus rufipennis). The peak beetle outbreak occurred in 2008, and has impacted 35% of the stems and 90% of the basal area of Engelmann spruce, which accounts for 30% of the trees and 70% of the basal area of the forest. Two semi-empirical light response curves for eddy-covariance carbon flux were compared, with a logistic sigmoid performing better because of residual bias than a rectangular hyperbola (Michaelis-Menten) at estimating the quantum yield of photosynthesis. In the first two years after the peak beetle outbreak the original quantum yield of 0.015 mol mol-1 was reduced by 25%. By the third year it was reduced by a half, which was composed of declines of 45% in the ecosystem's responses to diffuse radiation and 60% to direct radiation. The light-saturated rate of photosynthesis decreased by 10% in the first two years post outbreak, and fell by 40% in the third year. After the peak outbreak, the cumulative NEE over the growing season was reduced by over a half from a sink of 185 gC m-2 to 80 gC m-2, and by the third year it was reduced to near zero, or carbon neutral. The change in the ET response to light was similar in all years after the peak outbreak where the slope of the response curve was decreased by 25%. This led to a

  13. 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?

    Science.gov (United States)

    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].

  14. Capacitance-Assisted Sustainable Electrochemical Carbon Dioxide Mineralisation.

    Science.gov (United States)

    Lamb, Katie J; Dowsett, Mark R; Chatzipanagis, Konstantinos; Scullion, Zhan Wei; Kröger, Roland; Lee, James D; Aguiar, Pedro M; North, Michael; Parkin, Alison

    2018-01-10

    An electrochemical cell comprising a novel dual-component graphite and Earth-crust abundant metal anode, a hydrogen producing cathode and an aqueous sodium chloride electrolyte was constructed and used for carbon dioxide mineralisation. Under an atmosphere of 5 % carbon dioxide in nitrogen, the cell exhibited both capacitive and oxidative electrochemistry at the anode. The graphite acted as a supercapacitive reagent concentrator, pumping carbon dioxide into aqueous solution as hydrogen carbonate. Simultaneous oxidation of the anodic metal generated cations, which reacted with the hydrogen carbonate to give mineralised carbon dioxide. Whilst conventional electrochemical carbon dioxide reduction requires hydrogen, this cell generates hydrogen at the cathode. Carbon capture can be achieved in a highly sustainable manner using scrap metal within the anode, seawater as the electrolyte, an industrially relevant gas stream and a solar panel as an effective zero-carbon energy source. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  15. Enzymatic conversion of carbon dioxide.

    Science.gov (United States)

    Shi, Jiafu; Jiang, Yanjun; Jiang, Zhongyi; Wang, Xueyan; Wang, Xiaoli; Zhang, Shaohua; Han, Pingping; Yang, Chen

    2015-10-07

    With the continuous increase in fossil fuels consumption and the rapid growth of atmospheric CO2 concentration, the harmonious state between human and nature faces severe challenges. Exploring green and sustainable energy resources and devising efficient methods for CO2 capture, sequestration and utilization are urgently required. Converting CO2 into fuels/chemicals/materials as an indispensable element for CO2 capture, sequestration and utilization may offer a win-win strategy to both decrease the CO2 concentration and achieve the efficient exploitation of carbon resources. Among the current major methods (including chemical, photochemical, electrochemical and enzymatic methods), the enzymatic method, which is inspired by the CO2 metabolic process in cells, offers a green and potent alternative for efficient CO2 conversion due to its superior stereo-specificity and region/chemo-selectivity. Thus, in this tutorial review, we firstly provide a brief background about enzymatic conversion for CO2 capture, sequestration and utilization. Next, we depict six major routes of the CO2 metabolic process in cells, which are taken as the inspiration source for the construction of enzymatic systems in vitro. Next, we focus on the state-of-the-art routes for the catalytic conversion of CO2 by a single enzyme system and by a multienzyme system. Some emerging approaches and materials utilized for constructing single-enzyme/multienzyme systems to enhance the catalytic activity/stability will be highlighted. Finally, a summary about the current advances and the future perspectives of the enzymatic conversion of CO2 will be presented.

  16. Optimization of carbon dioxide fixation and starch accumulation by ...

    African Journals Online (AJOL)

    The effects of the initial biomass concentration (0.13, 0.8, 1.8, 2.8 and 3.47 g L-1), the gas flow rate (0.03, 0.1, 0.2, 0.3 and 0.37 V V-1 m-1) and different carbon dioxide concentrations (1.63, 5, 10, 15 and 18.37%) were considered using a central composite design. By using response surface methodology and the desirability ...

  17. Efficiency of Carbon Dioxide Fractional Laser in Skin Resurfacing

    Directory of Open Access Journals (Sweden)

    Andrej Petrov

    2016-05-01

    CONCLUSION: Multifunctional fractional carbon dioxide laser used in treatment of patients with acne and pigmentation from acne, as well as in the treatment of scars from different backgrounds, is an effective and safe method that causes statistically significant better effect of the treatment, greater patients’ satisfaction, minimal side effects and statistically better response to the therapy, according to assessments by the patient and the therapist.

  18. Effects of elevated carbon dioxide concentration on growth and N{sub 2} fixation of young Robinia pseudoacacia

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Z; Flessa, H. [University of Gottingen, Institute of soil Science and Forest Nutrition, Gottingen, (Germany); Dyckmans, J. [University College Dublin, Faculty of Agriculture, Environmental Resource Management, Dublin (Ireland)

    2004-03-01

    The effects of elevated carbon dioxide concentration on carbon and nitrogen uptake and nitrogen source partitioning were determined in one year-old locust trees using a dual 13{sup C} and 15{sup N} continuous labelling experiment. Elevated carbon dioxide increased the fraction of new carbon in total carbon, but it did not alter carbon partitioning among plant compartments. Elevated carbon dioxide also increased the fraction of new nitrogen in total nitrogen. This was coupled with a shift in nitrogen source partitioning toward nitrogen fixation. Soil nitrogen uptake was not affected, but nitrogen fixation was markedly increased by elevated carbon dioxide treatment. The increased nitrogen fixation tended to decrease the C/N ratio in the presence of elevated carbon dioxide. Total dry mass of root nodules doubled in response to elevated carbon dioxide, however, this effect was not considered significant because of the great variability in root nodule formation. Overall, it was concluded that the growth of locust trees in an elevated carbon dioxide environment will not primarily be limited by nitrogen availability, giving the R. pseudoacacia species a competitive advantage over non-nitrogen-fixing tree species. It was also suggested that the increase in nitrogen fixation observed in response to elevated carbon dioxide treatment may play a key role in the growth response of forest ecosystems to elevated carbon dioxide by improving nitrogen availability for non-nitrogen-fixing trees. 51 refs., 1 tab., 4 figs.

  19. 40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... operation. Adjust the analyzer to optimize performance. (2) Zero the carbon dioxide analyzer with either zero grade air or zero grade nitrogen. (3) Calibrate on each normally used operating range with carbon... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration...

  20. 40 CFR 91.320 - Carbon dioxide analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... the analyzer to optimize performance. (2) Zero the carbon dioxide analyzer with either purified synthetic air or zero-grade nitrogen. (3) Calibrate on each normally used operating range with carbon... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration...

  1. Modeling of the fixed - bed adsorption of carbon dioxide and a carbon dioxide - nitrogen mixture on zeolite 13X

    Directory of Open Access Journals (Sweden)

    T. L. P Dantas

    2011-09-01

    Full Text Available In this study, the fixed - bed adsorption of carbon dioxide and a carbon dioxide - nitrogen mixture on zeolite 13X was investigated. The adsorption equilibrium and breakthrough curves were determined at different temperatures - 301 - 306 K, 323 K, 373 K and 423 K. A model based on the LDF approximation for the mass transfer, considering the energy and momentum balances, was used to describe the adsorption kinetics of carbon dioxide and a carbon dioxide - nitrogen mixture. The model acceptably reproduced all of the breakthrough curves and can be considered as adequate for designing a PSA cycle to separate carbon dioxidenitrogen mixtures.

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

    Science.gov (United States)

    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.

  3. Changes in plasma potassium concentration during carbon dioxide pneumoperitoneum

    DEFF Research Database (Denmark)

    Perner, A; Bugge, K; Lyng, K M

    1999-01-01

    Hyperkalaemia with ECG changes had been noted during prolonged carbon dioxide pneumoperitoneum in pigs. We have compared plasma potassium concentrations during surgery in 11 patients allocated randomly to undergo either laparoscopic or open appendectomy and in another 17 patients allocated randomly...... to either carbon dioxide pneumoperitoneum or abdominal wall lifting for laparoscopic colectomy. Despite an increasing metabolic acidosis, prolonged carbon dioxide pneumoperitoneum resulted in only a slight increase in plasma potassium concentrations, which was both statistically and clinically insignificant...

  4. Measuring the human contribution to atmospheric carbon dioxide

    Science.gov (United States)

    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.

  5. Six-fold Coordinated Carbon Dioxide VI

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Cerebral blood volume response to changes in carbon dioxide tension before and during cardiopulmonary bypass in children, investigated by near infrared spectroscopy.

    Science.gov (United States)

    Fallon, P; Roberts, I G; Kirkham, F J; Edwards, A D; Lloyd-Thomas, A; Elliott, M J

    1994-01-01

    Neurological impairment may occur following cardiopulmonary bypass (CPB) and the effect of CPB on cerebrovascular control may be important in the mechanism of cerebral injury. We have used near infrared spectroscopy (NIRS) to observe cerebral haemodynamics non-invasively before and during CPB. We measured the change in cerebral blood volume (CBV) associated with changing PaCO2 (CBVR). Patients (n = 19) were aged from 1 to 135 (median 14) months. The cerebral blood volume response was determined pre-operatively at normothermia under the influence of standardised anaesthesia employing isoflurane (up to ET conc 0.5%) and during steady-state hypothermic bypass (22-32 degrees C) at an arterial pump flow rate of 1.9-2.4 lm-2.min-1. Complete data was available for 10 patients. The relation between CBV, arterial carbon dioxide tension (PaCO2), mean arterial pressure (MAP) and central venous pressure (CVP) was examined using analysis of covariance (P non-invasive technique for the investigation of cerebral haemodynamics during CPB.

  7. Carbon dioxide absorbent and method of using the same

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Effects of Elevated Carbon Dioxide on Litter Chemistry and Decomposition

    Data.gov (United States)

    National Aeronautics and Space Administration — The results of published and unpublished experiments investigating the impacts of elevated carbon dioxide on the chemistry (nitrogen and lignin concentration) of...

  9. Changes in plasma potassium concentration during carbon dioxide pneumoperitoneum

    DEFF Research Database (Denmark)

    Perner, A; Bugge, K; Lyng, K M

    1999-01-01

    Hyperkalaemia with ECG changes had been noted during prolonged carbon dioxide pneumoperitoneum in pigs. We have compared plasma potassium concentrations during surgery in 11 patients allocated randomly to undergo either laparoscopic or open appendectomy and in another 17 patients allocated randomly...... to either carbon dioxide pneumoperitoneum or abdominal wall lifting for laparoscopic colectomy. Despite an increasing metabolic acidosis, prolonged carbon dioxide pneumoperitoneum resulted in only a slight increase in plasma potassium concentrations, which was both statistically and clinically insignificant....... Thus hyperkalaemia is unlikely to develop in patients with normal renal function undergoing carbon dioxide pneumoperitoneum for laparoscopic surgery....

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

    Energy Technology Data Exchange (ETDEWEB)

    Laugier, S. [Ecole Nationale Superieure de Chimie et Physique de Bordeaux, Talence (France); Richon, D. [Ecole Nationale Superieure des Mines de Paris, Fontainebleau (France)

    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.

  11. A Vortex Contactor for Carbon Dioxide Separations

    Energy Technology Data Exchange (ETDEWEB)

    Raterman, Kevin Thomas; Mc Kellar, Michael George; Turner, Terry Donald; Podgorney, Anna Kristine; Stacey, Douglas Edwin; Stokes, B.; Vranicar, J.

    2001-05-01

    Many analysts identify carbon dioxide (CO2) capture and separation as a major roadblock in efforts to cost effectively mitigate greenhouse gas emissions via sequestration. An assessment 4 conducted by the International Energy Agency (IEA) Greenhouse Gas Research and Development Programme cited separation costs from $35 to $264 per tonne of CO2 avoided for a conventional coal fired power plant utilizing existing capture technologies. Because these costs equate to a greater than 40% increase in current power generation rates, it appears obvious that a significant improvement in CO2 separation technology is required if a negative impact on the world economy is to be avoided.

  12. Heat transfer coeffcient for boiling carbon dioxide

    DEFF Research Database (Denmark)

    Knudsen, Hans Jørgen Høgaard; Jensen, Per Henrik

    1997-01-01

    Heat transfer coefficient and pressure drop for boiling carbon dioxide (R744) flowing in a horizontal pipe has been measured. The pipe is heated by condensing R22 outside the pipe. The heat input is supplied by an electrical heater wich evaporates the R22. With the heat flux assumed constant over...... the whole surface and with measured temperature difference between the inner surface and the evaporation temperature a mean heat transfer coefficient is calculated. The calculated heat transfer coefficient has been compared with the Chart Correlation of Shah. The Chart Correlation predicts too low heat...

  13. Capture of carbon dioxide by hybrid sorption

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Biochemical acclimation patterns of Betula pendula and Pinus sylvestris seedlings to elevated carbon dioxide concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Juurola, E. [Helsinki Univ. (Finland). Dept. of Forest Ecology

    2003-02-01

    For a period of two years, the silver birch (Betula pendula) and Scots pine (Pinus sylvestris) seedlings and their respective acclimation of photosynthesis to increasing carbon dioxide concentrations were studied. The monitoring, with steady-state gas exchange at three carbon dioxide concentrations, included chlorophyll fluorescence and concentrations of Rubisco, chlorophyll, total soluble protein and nitrogen. The results indicated that in birch and Scots pine, the Rubisco and chlorophyll concentrations decreased as the carbon dioxide concentrations increased. For birch, Rubisco and chlorophyll yielded a non-linear response, and it was possible to correlate this response with a significant decrease in specific leaf area. In Scots pine needles, the nitrogen concentration remained unchanged, while it decreased in birch leaves. The steady-state carbon dioxide exchange response to increasing carbon dioxide concentrations differed between the two species. A significant non-linear decrease in the steady-state gas exchange rate at the ambient carbon dioxide was the main effect noted in birch. As for Scots pine, it was a significant increase in the steady-state gas exchange rate at the growth carbon dioxide. 45 refs., 9 figs.

  16. Killing wild geese with carbon dioxide or a mixture of carbon dioxide and argon

    NARCIS (Netherlands)

    Gerritzen, M.A.; Reimert, H.G.M.; Lourens, A.; Bracke, M.B.M.; Verhoeven, M.T.W.

    2013-01-01

    The killing of animals is the subject of societal and political debate. Wild geese are caught and killed on a regular basis for fauna conservation and damage control. Killing geese with carbon dioxide (CO2) is commonly practiced, but not listed in legislation on the protection of flora and fauna,

  17. Combined effect of sulfur dioxide and carbon dioxide gases on mold fungi

    Energy Technology Data Exchange (ETDEWEB)

    Kochurova, A.I.; Karpova, T.N.

    1974-01-01

    Sulfur dioxide at 0.08% killed Penicillium expansum, Stemphylium macrosporium, and Botrytis cinerea within 24 hours. At 0.2%, it killed P. citrinum, Alternaria tenuis, and Fusarium moniliforme. Sulfur dioxide (at 0.04%) and Sulfur dioxide-carbon dioxide mixtures (at 0.02 and 5% respectively) completely suppressed the growth of P. citrinum, P. expansum, P. rubrum, A. tenuis, S. macrosporium, B. cinerea, and F. moniliforme in laboratory experiments. 1 table.

  18. Cryogenic Adsorption of Nitrogen and Carbon Dioxide in Activated Carbon

    Science.gov (United States)

    Shen, Fuzhi; Liu, Huiming; Xu, Dong; Zhang, Hengcheng; Lu, Junfeng; Li, Laifeng

    2017-09-01

    Activated carbon have been used for a long time at low temperature for cryogenic applications. The knowledge of adsorption characteristics of activated carbon at cryogenic temperature is essential for some specific applications. However, such experimental data are very scare in the literature. In order to measure the adsorption characteristics of activated carbon under variable cryogenic temperatures, an adsorption measurement device was presented. The experiment system is based on the commercially available PCT-pro adsorption analyzer coupled to a two-stage Gifford McMahon refrigerator, which allows the sample to be cooled to 4.2K. Cryogenic environment can be maintained steadily without the cryogenic liquid through the cryocooler and temperature can be controlled precisely between 5K and 300K by the temperature controller. Adsorption measurements were performed in activated carbon for carbon dioxide and nitrogen and the adsorption isotherm were obtained.

  19. Carbon dioxide exchange in the Arctic

    DEFF Research Database (Denmark)

    Ravn, Nynne Marie Rand

    Low temperatures in the Arctic have through geological times caused a build-up of carbon (C) in the soil while carbon dioxide (CO2) has been removed from the atmosphere, because ecosystem respiration (ER) has been exceeded by the photosynthesis (GEP). Increasing air temperature, as occurring...... in current years, is likely to increase ER due to increased decomposition and increased substrate input e.g. due to permafrost thaw. If GEP is left unchanged and decomposition of old C from the soil is occurring this might result in an increase of the emission of CO2 to the atmosphere probably resulting...... fluxes and organic nutrient utilization between ecosystems occurring from different latitudes and dominated by different vegetation types. These aspects are important to understand the effects of climate change on the CO2 balance in the Arctic and its potential positive feedback on global climate change...

  20. Carbon Dioxide Capture Adsorbents: Chemistry and Methods.

    Science.gov (United States)

    Patel, Hasmukh A; Byun, Jeehye; Yavuz, Cafer T

    2017-04-10

    Excess carbon dioxide (CO 2 ) emissions and their inevitable consequences continue to stimulate hard debate and awareness in both academic and public spaces, despite the widespread lack of understanding on what really is needed to capture and store the unwanted CO 2 . Of the entire carbon capture and storage (CCS) operation, capture is the most costly process, consisting of nearly 70 % of the price tag. In this tutorial review, CO 2 capture science and technology based on adsorbents are described and evaluated in the context of chemistry and methods, after briefly introducing the current status of CO 2 emissions. An effective sorbent design is suggested, whereby six checkpoints are expected to be met: cost, capacity, selectivity, stability, recyclability, and fast kinetics. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. A miniature chemiresistor sensor for carbon dioxide.

    Science.gov (United States)

    Srinives, Sira; Sarkar, Tapan; Hernandez, Raul; Mulchandani, Ashok

    2015-05-18

    A carpet-like nanostructure of polyaniline (PANI) nanothin film functionalized with poly(ethyleneimine), PEI, was used as a miniature chemiresistor sensor for detection of CO2 at room temperature. Good sensing performance was observed upon exposing the PEI-PANI device to 50-5000 ppm CO2 in presence of humidity with negligible interference from ammonia, carbon monoxide, methane and nitrogen dioxide. The sensing mechanism relied on acid-base reaction, CO2 dissolution and amine-catalyzed hydration that yielded carbamates and carbonic acid for a subsequent pH detection. The sensing device showed reliable results in detecting an unknown concentration of CO2 in air. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Cooperative redox activation for carbon dioxide conversion.

    Science.gov (United States)

    Lian, Zhong; Nielsen, Dennis U; Lindhardt, Anders T; Daasbjerg, Kim; Skrydstrup, Troels

    2016-12-16

    A longstanding challenge in production chemistry is the development of catalytic methods for the transformation of carbon dioxide into useful chemicals. Silane and borane promoted reductions can be fined-tuned to provide a number of C1-building blocks under mild conditions, but these approaches are limited because of the production of stoichiometric waste compounds. Here we report on the conversion of CO2 with diaryldisilanes, which through cooperative redox activation generate carbon monoxide and a diaryldisiloxane that actively participate in a palladium-catalysed carbonylative Hiyama-Denmark coupling for the synthesis of an array of pharmaceutically relevant diarylketones. Thus the disilane reagent not only serves as the oxygen abstracting agent from CO2, but the silicon-containing 'waste', produced through oxygen insertion into the Si-Si bond, participates as a reagent for the transmetalation step in the carbonylative coupling. Hence this concept of cooperative redox activation opens up for new avenues in the conversion of CO2.

  3. Cooperative redox activation for carbon dioxide conversion

    Science.gov (United States)

    Lian, Zhong; Nielsen, Dennis U.; Lindhardt, Anders T.; Daasbjerg, Kim; Skrydstrup, Troels

    2016-12-01

    A longstanding challenge in production chemistry is the development of catalytic methods for the transformation of carbon dioxide into useful chemicals. Silane and borane promoted reductions can be fined-tuned to provide a number of C1-building blocks under mild conditions, but these approaches are limited because of the production of stoichiometric waste compounds. Here we report on the conversion of CO2 with diaryldisilanes, which through cooperative redox activation generate carbon monoxide and a diaryldisiloxane that actively participate in a palladium-catalysed carbonylative Hiyama-Denmark coupling for the synthesis of an array of pharmaceutically relevant diarylketones. Thus the disilane reagent not only serves as the oxygen abstracting agent from CO2, but the silicon-containing `waste', produced through oxygen insertion into the Si-Si bond, participates as a reagent for the transmetalation step in the carbonylative coupling. Hence this concept of cooperative redox activation opens up for new avenues in the conversion of CO2.

  4. Use of supercritical carbon dioxide extraction

    Energy Technology Data Exchange (ETDEWEB)

    Taniguchi, Masayuki (Niigata Univ., Faculty of Engineering, Niigata, (Japan))

    1989-09-25

    Supercritical fluid extraction is a novel diffusion and separation technique which exploits simultaneously the increase of vapor pressure and the difference of chemical affinities of fluids near the critical point. A solvent which is used as the supercritical fluid has the following features: the critical point exists in the position of relatively ease of handling, the solvent is applicable to the extraction of a physiological active substance of thermal instability. Carbon dioxide as the solvent is non-flammable, non-corrosive, non-toxic, cheap, and readily available of high purity. The results of studies on the use of supercritical carbon dioxide (SC-CO{sub 2}) as a solvent for natural products in the fermentation and food industries, were collected. SC-CO{sub 2} extraction are used in many fields, examples for the application are as follows: removal of organic solvents from antibiotics; extraction of vegetable oils contained in wheat germ oil, high quality mustard seeds, rice bran and so on; brewing of sake using rice and rice-koji; use as a non-aqueous medium for the synthesis of precursors of the Aspartame; and use in sterilization. 66 refs., 17 figs., 21 tabs.

  5. Performance, acute health symptoms and physiological responses during exposure to high air temperature and carbon dioxide concentration

    DEFF Research Database (Denmark)

    liu, weiwei; Zhong, Weidi; Wargocki, Pawel

    2017-01-01

    Human subjects were exposed for 3 h in a climate chamber to the air temperature of 35 °C that is an action level, at which the working time needs to be diminished in China. The purpose was to put this action level to test by measuring physiological responses, subjective ratings and cognitive...... performance, and compare them with responses at temperature of 26 °C (reference exposure). Moreover, CO2 was increased to 3000 ppm (CO2 exposure) at 35 °C to further examine, whether this change will have any effect on the measured responses. Compared with the reference exposure, exposure to 35 °C caused...... ppm at 35 °C caused no significant changes in responses. Present results reaffirm the selection of 35 °C as an action level, and show that concurrently occurring high CO2 levels should not exacerbate the hazards....

  6. Impact of needle age on the response of respiration in Scots pine to long-term elevation of carbon dioxide concentration and temperature.

    Science.gov (United States)

    Zha, Tianshan; Wang, Kai-Yun; Ryyppö, Aija; Kellomäki, Seppo

    2002-12-01

    Sixteen 20-year-old Scots pine (Pinus sylvestris L.) trees growing in the field were enclosed in environment-controlled chambers that for 4 years maintained: (1) ambient conditions (CON); (2) elevated atmospheric carbon dioxide concentration [CO2] (ambient + 350 micromol mol-1; EC); (3) elevated temperature (ambient + 2-3 degrees C; ET); or (4) elevated [CO2] and temperature (EC+ET). Dark respiration rate, specific leaf area (SLA) and the concentrations of starch and soluble sugars in needles were measured in the fourth year. Respiration rates, on both an area and a mass basis, and SLA decreased in EC relative to CON, but increased in ET and EC+ET, regardless of needle age class. Starch and soluble sugar concentrations for a given needle age class increased in EC, but decreased slightly in ET and EC+ET. Respiration rates and SLA were highest in current-year needles in all treatments, whereas starch and soluble sugar concentrations were highest in 1-year-old needles. Relative to that of older needles, respiration of current-year needles was inhibited less by EC, but increased in response to ET and EC+ET. All treatments enhanced the difference in respiration between current-year and older needles relative to that in CON. Age had a greater effect on needle respiration than any of the treatments. There were no differences in carbohydrate concentration or SLA between needle age classes in response to any treatment. Relative to CON, the temperature coefficient (Q10) of respiration increased slightly in EC, regardless of age, but declined significantly in ET and EC+ET, indicating acclimation of respiration to temperature.

  7. The effect of cutting on carbon dioxide absorption and carbohydrate ...

    African Journals Online (AJOL)

    grass) and Osteospermun sinuatum (Karoo-bush) plants during the flag leaf and flower bud stages respectively resulted in a sharp decline in net carbon dioxide absorption. As new photosynthetic material was produced the total carbon ...

  8. Hydrodynamic Controls on Carbon Dioxide Efflux from Inland Waters

    Science.gov (United States)

    Long, H. E.; Waldron, S.; Hoey, T.; Newton, J.; Quemin, S.

    2013-12-01

    Intensive research has been undertaken on carbon dioxide efflux from lakes, estuaries and oceans, but much less attention has been given to rivers and streams, especially lower order streams. River systems are often over-saturated with carbon dioxide and so tend to act as sources of carbon dioxide to the atmosphere. It has been thought that rivers act as pipes carrying this terrestrial carbon to the oceans. However, recent studies have shown that a significant amount of the carbon is reprocessed within the system in a series of transformations and losses. Fluvial evasion of carbon dioxide is now recognised to be a significant component of carbon cycles, however the factors controlling carbon dioxide efflux and its magnitude remain poorly understood and quantified. This research aims to quantify, and better understand the controls on, freshwater carbon dioxide evasion. Data are presented here from field measurements that commenced in Sept 2013 in two contrasting Scottish rivers: the River Kelvin which has a large (335 km.sq) part-urban catchment with predominantly non-peat soils and Drumtee Water, a small (9.6 km.sq) rural catchment of peat soils and agricultural land. Using a floating chamber with the headspace connected to an infrared gas analyser to measure changes in carbon dioxide concentration, efflux rates from 0.22 - 47.4 μmol CO2/m.sq/sec were measured, these close to the middle of the range of previously reported values. At one site on the River Kelvin in May 2013 an influx of -0.61 - -3.53 μmol CO2/m.sq/sec was recorded. Whereas previous research finds carbon dioxide efflux to increase with decreasing river size and a more organic-rich soil catchment, here the controls on carbon dioxide evasion are similar across the contrasting catchments. Carbon dioxide evasion shows seasonality, with maximum fluxes in the summer months being up to twice as high as the winter maxima. Linear regression demonstrates that evasion increases with increased flow velocity

  9. Promising flame retardant textile in supercritical carbon dioxide

    Science.gov (United States)

    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...

  10. Interglacials, Milankovitch Cycles, Solar Activity, and Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Gerald E. Marsh

    2014-01-01

    Full Text Available The existing understanding of interglacial periods is that they are initiated by Milankovitch cycles enhanced by rising atmospheric carbon dioxide concentrations. During interglacials, global temperature is also believed to be primarily controlled by carbon dioxide concentrations, modulated by internal processes such as the Pacific Decadal Oscillation and the North Atlantic Oscillation. Recent work challenges the fundamental basis of these conceptions.

  11. Stability of wheat germ oil obtained by supercritical carbon dioxide ...

    African Journals Online (AJOL)

    심정은

    Wheat germ oil was extracted using an environmental friendly solvent, supercritical carbon dioxide (SC-. CO2) at a semi-batch flow extraction process. The supercritical carbon dioxide (SC-CO2) extraction was carried out to extract oil at temperature of 40°C and pressure of 25 MPa. Ethanolysis was performed with 1 ...

  12. Carbon Dioxide Production in Animal Houses: A literature review

    NARCIS (Netherlands)

    Pedersen, S.; Blanes-Vidal, V.; Joergensen, H.; Chwalibog, A.; Haeussermann, A.; Heetkamp, M.J.W.; Aarnink, A.J.A.

    2008-01-01

    This article deals with carbon dioxide production from farm animals; more specifically, it addresses the possibilities of using the measured carbon dioxide concentration in animal houses as basis for estimation of ventilation flow (as the ventilation flow is a key parameter of aerial emissions from

  13. Carbon dioxide (CO 2 ) utilizing strain database | Saini | African ...

    African Journals Online (AJOL)

    The biological means of CO2 fixation using various microorganisms is gaining importance because database of their substantial role in reversing global warming. Carbon dioxide utilizing strain database (CSD) presents a comprehensive overview of microorganisms involved in biological fixation of carbon dioxide. As a part ...

  14. Carbon Dioxide and Global Warming: A Failed Experiment

    Science.gov (United States)

    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…

  15. Effect of high pressurized carbon dioxide on Escherichia coli ...

    African Journals Online (AJOL)

    Carbon dioxide at high pressure can retard microbial growth and sometimes kill microorganisms depending on values of applied pressure, temperature and exposure time. In this study the effect of high pressurised carbon dioxide (HPCD) on Escherichia coli was investigated. Culture of E. coli was subjected to high ...

  16. Stability of wheat germ oil obtained by supercritical carbon dioxide ...

    African Journals Online (AJOL)

    Wheat germ oil was extracted using an environmental friendly solvent, supercritical carbon dioxide (SCCO2) at a semi-batch flow extraction process. The supercritical carbon dioxide (SC-CO2) extraction was carried out to extract oil at temperature of 40°C and pressure of 25 MPa. Ethanolysis was performed with 1 ...

  17. Combined reactions and separations using ionic liquids and carbon dioxide

    NARCIS (Netherlands)

    Kroon, M.C.

    2006-01-01

    A new and general type of process for the chemical industry is presented using ionic liquids and supercritical carbon dioxide as combined reaction and separation media. In this process, the carbon dioxide pressure controls the miscibility of reactants, products, catalyst and ionic liquid, enabling

  18. Kenaf seed oil from supercritical carbon dioxide fluid extraction ...

    African Journals Online (AJOL)

    Administrator

    2011-06-15

    Jun 15, 2011 ... Full Length Research Paper. Kenaf seed oil from supercritical carbon dioxide fluid .... The cells were harvested and washed twice with phosphate- buffered saline (PBS), fixed in ice-cold 70% ethanol and ..... Extraction of coffee diterpenes and coffee oil using supercritical carbon dioxide. Food Chem.

  19. Carbon dioxide capture processes: Simulation, design and sensitivity analysis

    DEFF Research Database (Denmark)

    Zaman, Muhammad; Lee, Jay Hyung; Gani, Rafiqul

    2012-01-01

    Carbon dioxide is the main greenhouse gas and its major source is combustion of fossil fuels for power generation. The objective of this study is to carry out the steady-state sensitivity analysis for chemical absorption of carbon dioxide capture from flue gas using monoethanolamine solvent. First...

  20. Metathesis of carbon dioxide and phenyl isocyanate catalysed by ...

    Indian Academy of Sciences (India)

    Carbodiimide metathesis is catalysed by a number of complexes leading to formation of unsymmetrical carbodiimides.1 Group 14 compounds are known to catalyse metathesis of phenyl isocyanates to give N, N′ diphenyl carbodiimides and carbon dioxide.2 The reverse reaction, metathesis of carbon dioxide with.

  1. Transient Atmospheric Circulation Response to An Instantaneous Doubling of Carbon Dioxide: Understanding Cause and Effect in Atmospheric Circulation Adjustment to Global Warming

    Science.gov (United States)

    Wu, Y.; Seager, R.; Ting, M.; Naik, N.; Shaw, T. A.

    2011-12-01

    As a consequence of increased carbon dioxide emission, the atmospheric general circulation is expected to change. IPCC AR4 coupled models have consistently projected a poleward shift in tropospheric zonal jets and midlatitude storm tracks. We explore the associated dynamical mechanisms by looking into the transient step-by-step adjustment of the circulation. This allows an assessment of the causality sequence in the circulation and thermal structure response prior to establishment of a quasi-equilibrium state. The transient atmospheric adjustment is examined using the National Center for Atmospheric Research Community Atmospheric Model Version 3 coupled to a slab ocean model and the CO2 concentration in the atmosphere is uniformly and instantaneously doubled. The thermal structure and circulation response is well established after one year of integration with the magnitudes gradually increasing afterwards towards quasi-equilibrium. Tropical upper tropospheric warming occurs in the first month. The expansion of the warming in the middle and upper troposphere to the subtropics occurs later and is found to be primarily dynamically-driven due to the intensification of transient eddy momentum flux convergence and resulting anomalous descending motion in this region. This linkage between the eddy-driven vertical motion anomaly and the subtropical warming expansion in the middle and upper troposphere is also confirmed in the late 21st century in the IPCC AR4 simulations. The poleward displacement of the midlatitude tropospheric jet streams occurs together with the change in eddy momentum flux convergence but only after the intensification of the subpolar westerlies in the stratosphere. The results demonstrate the importance of the tropospheric eddies in setting up the extratropical tropospheric response to global warming. Our modeling results also show the sequence of the zonal wind anomaly in the vertical column of the atmosphere during the period of transient adjustment

  2. Carbon dioxide stripping in aquaculture. part 1: terminology and reporting

    Science.gov (United States)

    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.

  3. The Effect of Exports on Carbon Dioxide Emissions: Policy Implications

    Directory of Open Access Journals (Sweden)

    Bosupeng Mpho

    2016-09-01

    Full Text Available The purpose of this study is to explore long run affiliations between exports and carbon dioxide emissions. This paper examines thirty-seven countries over the period 1960 to 2010 and uses the Toda and Yamamoto causality approach to investigate the direction of causal links. The results reveal that carbon dioxide emissions Granger cause exports in the following economies: Bolivia, Canada, Costa Rica, Morocco, Austria and Ireland. Nonetheless, the reverse causality proved that exports Granger cause carbon dioxide emissions in twelve economies. Furthermore, the study registered bidirectional causal links between exports and carbon dioxide emissions in the USA and Burkina Faso. We conclude that countries should consider exports market demand, energy consumption and economic growth in their attempts to reduce carbon dioxide emissions.

  4. Carbon dioxide absorbent and method of using the same

    Science.gov (United States)

    Perry, Robert James [Niskayuna, NY; Lewis, Larry Neil [Scotia, NY; O'Brien, Michael Joseph [Clifton Park, NY; Soloveichik, Grigorii Lev [Latham, NY; Kniajanski, Sergei [Clifton Park, NY; Lam, Tunchiao Hubert [Clifton Park, NY; Lee, Julia Lam [Niskayuna, NY; Rubinsztajn, Malgorzata Iwona [Ballston Spa, NY

    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.

  5. Effects of Elevated Carbon Dioxide on Photosynthesis and Carbon Partitioning: A Perspective on Root Sugar Sensing and Hormonal Crosstalk

    OpenAIRE

    Thompson, Michael; Gamage, Dananjali; Hirotsu, Naoki; Martin, Anke; Seneweera, Saman

    2017-01-01

    Plant responses to atmospheric carbon dioxide will be of great concern in the future, as carbon dioxide concentrations ([CO2]) are predicted to continue to rise. Elevated [CO2] causes increased photosynthesis in plants, which leads to greater production of carbohydrates and biomass. Which organ the extra carbohydrates are allocated to varies between species, but also within species. These carbohydrates are a major energy source for plant growth, but they also act as signaling molecules and ha...

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

    Science.gov (United States)

    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.

  7. Global carbon dioxide emissions from inland waters

    Science.gov (United States)

    Raymond, Peter A.; Hartmann, Jens; Lauerwald, Ronny; Sobek, Sebastian; McDonald, Cory P.; Hoover, Mark; Butman, David; Striegl, Robert G.; 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.

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

    Science.gov (United States)

    Wang, Lei; Liu, Huizhi; Bernhofer, Christian

    2017-05-01

    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.

  9. Growth and physiological responses of canola (Brassica napus) to three components of global climate change: temperature, carbon dioxide and drought

    Energy Technology Data Exchange (ETDEWEB)

    Qaderi, M.M.; Kurepin, L.V.; Reid, D.M. [Univ. of Calgary, Dept. of Biological Sciences, Calgary, Alberta (Canada)

    2006-12-15

    Elevated CO{sub 2} appears to be a significant factor in global warming, which will likely lead to drought conditions in many areas. Few studies have considered the interactive effects of higher CO{sub 2}, temperature and drought on plant growth and physiology. We grew canola (Brassica napus cv. 45H72) plants under lower (22/18 deg. C) and higher (28/24 deg. C) temperature regimes in controlled-environment chambers at ambient (370 {mu}mol mol-1) and elevated (740 {mu}mol mol-1) CO{sub 2} levels. One half of the plants were watered to field capacity and the other half at wilting point. In three separate experiments, we determined growth, various physiological parameters and content of abscisic acid (ABA), indole-3-acetic acid and ethylene. Drought-stressed plants grown under higher temperature at ambient CO{sub 2} had decreased stem height and diameter, leaf number and area, dry matter, leaf area ratio, shoot/root weight ratio, net CO{sub 2} assimilation and chlorophyll fluorescence. However, these plants had increased specific leaf weight, leaf weight ratio and chlorophyll concentration. Elevated CO{sub 2} generally had the opposite effect. and partially reversed the inhibitory effects of higher temperature and drought on leaf dry weight accumulation. This study showed that higher temperature and drought inhibit many processes but elevated CO{sub 2} partially mitigate some adverse effects. As expected, drought stress increased ABA but higher temperature inhibited the ability of plants to produce ABA in response to drought. (au)

  10. Layered solid sorbents for carbon dioxide capture

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Carbon dioxide removal with inorganic membranes

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-12-31

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

  12. Carbon dioxide neutral, integrated biofuel facility

    Energy Technology Data Exchange (ETDEWEB)

    Powell, E.E.; Hill, G.A. [Department of Chemical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, Saskatchewan, S7N 5A9 (Canada)

    2010-12-15

    Algae are efficient biocatalysts for both capture and conversion of carbon dioxide in the environment. In earlier work, we have optimized the ability of Chlorella vulgaris to rapidly capture CO{sub 2} from man-made emission sources by varying environmental growth conditions and bioreactor design. Here we demonstrate that a coupled biodiesel-bioethanol facility, using yeast to produce ethanol and photosynthetic algae to produce biodiesel, can result in an integrated, economical, large-scale process for biofuel production. Each bioreactor acts as an electrode for a coupled complete microbial fuel cell system; the integrated cultures produce electricity that is consumed as an energy source within the process. Finally, both the produced yeast and spent algae biomass can be used as added value byproducts in the feed or food industries. Using cost and revenue estimations, an IRR of up to 25% is calculated using a 5 year project lifespan. (author)

  13. Biochemical Capture and Removal of Carbon Dioxide

    Science.gov (United States)

    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.

  14. Layered solid sorbents for carbon dioxide capture

    Science.gov (United States)

    Li, Bingyun; Jiang, Bingbing; Gray, McMahan L; Fauth, Daniel J; Pennline, Henry W; Richards, George A

    2013-02-25

    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.

  15. Photosynthesis acclimation, leaf nitrogen concentration, and growth of four tree species over 3 years in response to elevated carbon dioxide and nitrogen treatment in subtropical China

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Juxiu; Zhou, Guoyi; Duan, Honglang; Li, Yuelin; Zhang, Deqiang [Chinese Academy of Sciences, Guangzhou (China). South China Botanical Garden; Xu, Zhihong [Griffith Univ., Nathan, Brisbane (Australia). Centre for Forestry and Horticultural Research

    2011-10-15

    Up to date, most studies about the plant photosynthetic acclimation responses to elevated carbon dioxide (CO{sub 2}) concentration have been performed in temperate areas, which are often N limited under natural conditions and with low ambient N deposition. It is unclear whether photosynthetic downregulation is alleviated with increased N availability, for example, from increased N deposition due to fossil fuel combustion in the tropics and subtropics. Awareness of plant photosynthetic responses to elevated CO{sub 2} concentration will contribute to the better understanding and prediction of future forest productivity under global change. Four tree species, Schima superba Gardn. et Champ., Ormosia pinnata (Lour.) Merr, Castanopsis hystrix AC. DC., and Acmena acuminatissima (Blume) Merr. et Perry were exposed to a factorial combination of atmospheric CO{sub 2} concentration (ambient and elevated CO{sub 2} concentration at ca. 700 {mu}mol CO{sub 2} mol{sup -1}) and N deposition (ambient and ambient + 100 kg N ha{sup -1} year{sup -1}) in open-top chambers in southern China for 3 years since March 2005. Light-saturated net photosynthetic rate, leaf N concentration, and tree growth of all species were measured. The CO{sub 2} treatments did not affect light-saturated net photosynthetic rate of all species grown with the high N treatment. However, S. superba grown with the low N treatment (ambient) had 23% and 47% greater net photosynthesis in the ambient CO{sub 2} concentration than those in the elevated CO{sub 2} concentration for December 2006 and November 2007 (20 and 31 months after the treatments were applied), respectively, and A. acuminatissima grown with the low N treatment had 173%, 26%, and 121% greater net photosynthesis in trees grown in the ambient CO{sub 2} concentration than those in the elevated CO{sub 2} concentration for July 2006 (16 months after the treatments), December 2006 (20 months), and November 2007 (31 months), respectively, whereas

  16. Development of a low cost unmanned aircraft system for atmospheric carbon dioxide leak detection

    Science.gov (United States)

    Mitchell, Taylor Austin

    Carbon sequestration, the storage of carbon dioxide gas underground, has the potential to reduce global warming by removing a greenhouse gas from the atmosphere. These storage sites, however, must first be monitored to detect if carbon dioxide is leaking back out to the atmosphere. As an alternative to traditional large ground-based sensor networks to monitor CO2 levels for leaks, unmanned aircraft offer the potential to perform in-situ atmospheric leak detection over large areas for a fraction of the cost. This project developed a proof-of-concept sensor system to map relative carbon dioxide levels to detect potential leaks. The sensor system included a Sensair K-30 FR CO2 sensor, GPS, and altimeter connected an Arduino microcontroller which logged data to an onboard SD card. Ground tests were performed to verify and calibrate the system including wind tunnel tests to determine the optimal configuration of the system for the quickest response time (4-8 seconds based upon flowrate). Tests were then conducted over a controlled release of CO 2 in addition to over controlled rangeland fires which released carbon dioxide over a large area as would be expected from a carbon sequestration source. 3D maps of carbon dioxide were developed from the system telemetry that clearly illustrated increased CO2 levels from the fires. These tests demonstrated the system's ability to detect increased carbon dioxide concentrations in the atmosphere.

  17. Analysis of Supercritical Carbon Dioxide Heat Exchangers in Cooling Process

    OpenAIRE

    Chen, Yang; Lundqvist, Per

    2006-01-01

    Carbon dioxide transcritical cycles have become more and more investigated during the last decade. For all systems operating with such a cycle, there will be at least one heat exchanger to either heat or cool the supercritical carbon dioxide. Unlike in the sub-critical region, the supercritical carbon dioxide’s thermophysical properties will have sharp variations in the region close to its critical point. This variation has a significant influence on the shape of the heat exchanger’s temperat...

  18. Sequestration of carbon dioxide (CO2) using red mud.

    Science.gov (United States)

    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. 2009 Elsevier B.V. All rights reserved.

  19. Pysical fixation of carbon dioxide. Butsuritekina nisanka tanso no kotei

    Energy Technology Data Exchange (ETDEWEB)

    Akai, M. (Mechanical Engineering Laboratory, Tsukuba (Japen))

    1991-10-20

    Together with the introduction of physical fixation technology of carbon dioxide, possibility and problem are to be explained of carbon dioxide fixation by utilizing the deep-sea water in the ocean. The physical fixation methods comprise, among others, the oceanic fixation method, high pressure storage method in the exhausted oil or gas field and high pressure storage method into the rock salt piles. The oceanic fixation method has recently come to be studied in Japan also as having utilizable environments therearound. The oceanographic fixation technology of carbon dioxide is of an engineeringwise developed method. Particularly among others, the fixation technology to utilize deep-sea water, deeper than several hundreds of meters, heightens the carbon dioxide in solubility by availing of a condition of low temperature by high pressure. The liquefaction pressure of carbon dioxide being approx. 70atm at ordinary temperature, the liquefied carbon dioxide is higher in density than the sea water under a higher pressure than about 3000m in head. Due to the existence of temperature lamination, the absorbed carbon dioxide hardly circulates into the atmosphere. Apart from the above two points of advantage, it is advantageous also in other points. However, there remain many problems, inclusive of those ot basic mechanism, to be elucidated. 16 refs., 3 figs.

  20. Growth, Yield, and Nutritional Responses of Chamber-Grown Sweet Potato to Elevated Carbon Dioxide Levels Expected Across the Next 200 Years

    Science.gov (United States)

    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

  1. Forest management techniques for carbon dioxide storage

    Energy Technology Data Exchange (ETDEWEB)

    Fujimori, Takao [Forestry and Forest Products Research Inst., Tsukuba, Ibaraki (Japan)

    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.

  2. Carbon dioxide warming of the early Earth

    Science.gov (United States)

    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.

  3. Carbon Dioxide Information Analysis Center: FY 1992 activities

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, R.M. [Oak Ridge National Lab., TN (United States). Carbon Dioxide Information Analysis Center; Stoss, F.W. [Tennessee Univ., Knoxville, TN (United States). Energy, Environment and Resources Center

    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.

  4. Carbon Dioxide Information Analysis Center: FY 1991 activities

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Carbon Dioxide Information Analysis Center: FY 1991 activities

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Conversion Of Carbon Dioxide To Hydrocarbons Using Iron Nanoparticle-Carbon Nanotube Catalysts

    OpenAIRE

    Minett, Daniel

    2013-01-01

    Dealing with carbon dioxide waste is an on-going societal and technological challenge. One attractive proposition is to chemically convert waste carbon dioxide into useful chemical products. One possible route is to combine two well-known chemical processes, reverse water gas shift and Fischer-Tropsch synthesis, to make a catalyst capable of converting carbon dioxide directly intohydrocarbons. Iron nanoparticles supported on carbon nanotubes (CNT) have shown promise in the Fischer-Tropsch pro...

  7. Carbon Dioxide-Water Emulsions for Enhanced Oil Recovery and Permanent Sequestration of Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    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. Understanding how individuals perceive carbon dioxide. Implications for acceptance of carbon dioxide capture and storage

    Energy Technology Data Exchange (ETDEWEB)

    Itaoka, K.; Saito, A. [Mizuho Information and Research Institute, Tokyo (Japan); Paukovic, M.; De Best-Waldhober, M. [ECN Policy Studies, Petten (Netherlands); Dowd, A.M.; Jeanneret, T.; Ashworth, P.; James, M. [The Global CCS Institute, Canberra (Australia)

    2012-06-15

    Carbon dioxide capture and storage (CCS) presents one potential technological solution for mitigating the atmospheric emission of carbon dioxide sources. However, CCS is a relatively new technology with associated uncertainties and perceived risks. For this reason, a growing body of research now focuses on public perceptions and potential for societal acceptance of CCS technology. Almost all explanations of CCS technology make reference to carbon dioxide, with an assumption that the general public understands CO2. It has become apparent that the general public’s knowledge and understanding of CO2’s properties influences how they engage with CO2 emitting industries and CCS technologies. However, surprisingly little research has investigated public perceptions, knowledge, and understanding of CO2. This investigation attempts to fill that gap. This report describes an investigation of how citizens of three countries (Japan, Australia, and the Netherlands) perceive CO2. Furthermore, it attempts to relate individual perceptions of CO2 to perceptions of CCS, and to determine how information provision about the underlying properties and characteristics of CO2 influences individual attitudes towards low carbon energy options, particularly CCS. In brief, the research had four ultimate aims. It aimed to: Explore the public’s knowledge and understanding of the properties of CO2; Examine the influence of that knowledge on their perceptions of CO2 and CCS; Investigate how information provision about the underlying properties and characteristics of CO2 influences individual attitudes towards CCS; and Identify if any differences between countries exist in relation to values and beliefs, knowledge of CO2’s properties, and CCS perceptions.

  9. Synthesis of dimethyl carbonate in supercritical carbon dioxide

    Directory of Open Access Journals (Sweden)

    D. Ballivet-Tkatchenko

    2006-03-01

    Full Text Available The reactivity of carbon dioxide with methanol to form dimethyl carbonate was studied in the presence of the n-butylmethoxytin compounds n-Bu3SnOCH3, n-Bu2Sn(OCH32 , and [n-Bu2(CH3OSn]2 O. The reaction occurred under solventless conditions at 423 K and was produced by an increase in CO2 pressure. This beneficial effect is primarily attributed to phase behavior. The mass transfer under liquid-vapor biphasic conditions was not limiting when the system reached the supercritical state for a CO2 pressure higher than 16 MPa. Under these conditions, CO2 acted as a reactant and a solvent.

  10. Membranes for separation of carbon dioxide

    Science.gov (United States)

    Ku, Anthony Yu-Chung [Rexford, NY; Ruud, James Anthony [Delmar, NY; Ramaswamy, Vidya [Niskayuna, NY; Willson, Patrick Daniel [Latham, NY; Gao, Yan [Niskayuna, NY

    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.

  11. Carbon ion pump for removal of carbon dioxide from combustion gas and other gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Carbon ion pump for removal of carbon dioxide from combustion gas and other gas mixtures

    Science.gov (United States)

    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.

  13. Air quality assessment of carbon monoxide, nitrogen dioxide and ...

    African Journals Online (AJOL)

    Air quality in urban areas is a cause of concern because of increased industrial activities that contribute to large quantities of emissions. The study assess levels and variations of carbon monoxide (CO), nitrogen dioxide (NO2) and sulfur dioxide (SO2) in Blantyre, Malawi using a stationary environmental monitoring station ...

  14. Past explosive outbursts of entrapped carbon dioxide in salt mines provide a new perspective on the hazards of carbon dioxide

    DEFF Research Database (Denmark)

    Hedlund, Frank Huess

    2013-01-01

    This paper reports on a source of past carbon dioxide accidents which so far has only been sporadically mentioned in the literature. Violent and highly destructive outbursts of hundreds of tons of CO2 occurred regularly, if not routinely, in the now closed salt mines of the former DDR....... The Menzengraben mine experienced an extreme outburst in 1953, possibly involving a several thousand tons of carbon dioxide. This source of accidents fills an important gap in the available carbon dioxide accident history and may provide a unique empirical perspective on the hazards of handling very large amounts...

  15. 21 CFR 862.1160 - Bicarbonate/carbon dioxide test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 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 whole...

  16. 49 CFR 195.4 - Compatibility necessary for transportation of hazardous liquids or carbon dioxide.

    Science.gov (United States)

    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 both...

  17. Gas Flaring: Carbon dioxide Contribution to Global Warming ...

    African Journals Online (AJOL)

    PROF HORSFALL

    .info and www.bioline.org.br/ja. Gas Flaring: Carbon dioxide Contribution to Global Warming. *AMAECHI ... contributor to global warming, environmental degradation, health risk and economic loss. The ... risks of climate change. Meeting ...

  18. Drying of supercritical carbon dioxide with membrane processes

    NARCIS (Netherlands)

    Lohaus, Theresa; Scholz, Marco; Koziara, Beata; Benes, Nieck Edwin; Wessling, Matthias

    2015-01-01

    In supercritical extraction processes regenerating the supercritical fluid represents the main cost constraint. Membrane technology has potential for cost efficient regeneration of water-loaded supercritical carbon dioxide. In this study we have designed membrane-based processes to dehydrate

  19. Elevated carbon dioxide: impacts on soil and plant water relations

    National Research Council Canada - National Science Library

    Kirkham, M. B

    2011-01-01

    .... Focusing on this critical issue, Elevated Carbon Dioxide: Impacts on Soil and Plant Water Relations presents research conducted on field-grown sorghum, winter wheat, and rangeland plants under elevated CO2...

  20. Precision remote sensor for oxygen and carbon dioxide Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Mesa Photonics proposes development of a passive optical sensor for simultaneous high-precision measurement of oxygen and carbon dioxide profiles within the full...

  1. The oxygen and carbon dioxide balance in the earth's atmosphere

    Science.gov (United States)

    Johnson, F. S.

    1975-01-01

    The oxygen-carbon dioxide cycle is described in detail, and steps which are sensitive to perturbation or instability are identified. About half of the carbon dioxide consumption each year in photosynthesis occurs in the oceans. Phytoplankton, which are the primary producers, have been shown to assimilate insecticides and herbicides. The impact of such materials on phytoplankton photosynthesis, both direct and as the indirect result of detrimental effects higher up in the food chain, cannot be assessed. Net oxygen production is very small in comparison with the total production and occurs almost exclusively in a few ocean areas with anoxic bottom conditions and in peat-forming marshes which are sensitive to anthropogenic disturbances. The carbon dioxide content of the atmosphere is increasing at a relatively rapid rate as the result of fossil fuel combustion. Increases in photosynthesis as the result of the hothouse effect may in turn reduce the carbon dioxide content of the atmosphere, leading to global cooling.

  2. Removing carbon dioxide from a stationary source through co ...

    African Journals Online (AJOL)

    Thomas

    . INTRODUCTION. It is estimated that the global average temperature will rise between 1.4-5.8°C by the year 2100. The contributors to greenhouse effects are carbon dioxide. (CO2), chlorofluorocarbons (CFCs), methane (CH4) and.

  3. Kenaf seed oil from supercritical carbon dioxide fluid extraction ...

    African Journals Online (AJOL)

    Hibiscus cannabinus) variety V36 extracted using supercritical carbon dioxide fluid extraction (SFE) with different combinations of pressure (bars) and temperature (°C). Extracted oils were tested on human promyelocytic HL-60, murine ...

  4. Miniature Carbon Dioxide Sensor for Small Unmanned Aircraft Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Phase 1 has seen the development of a revolutionary new type of sensor for making carbon dioxide (CO2) measurements from small Unmanned Aircraft Systems (UAS) and...

  5. Miniature Carbon Dioxide Sensor for Small Unmanned Aircraft Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — There is a growing need to develop improved technologies for precise airborne measurements of carbon dioxide, CO2. CO2 measurements are of great importance to many...

  6. Electrochemical Reactor for Producing Oxygen From Carbon Dioxide Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An electrochemical reactor is proposed by MicroCell Technologies, LLC to electrochemically reduce carbon dioxide to oxygen. In support of NASA's advanced life...

  7. ISLSCP II Air-Sea Carbon Dioxide Gas Exchange

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains the calculated net ocean-air carbon dioxide (CO2) flux and sea-air CO2 partial pressure (pCO2) difference. The estimates are based on...

  8. ISLSCP II Air-Sea Carbon Dioxide Gas Exchange

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set contains the calculated net ocean-air carbon dioxide (CO2) flux and sea-air CO2 partial pressure (pCO2) difference. The estimates are based...

  9. Monthly Carbon Dioxide in Troposphere (AIRS on AQUA)

    Data.gov (United States)

    National Aeronautics and Space Administration — Carbon dioxide (CO2) is an important greenhouse gas released through natural processes such as respiration and volcano eruptions and through huma activities such as...

  10. Carbon dioxide balneotherapy and cardiovascular disease

    Science.gov (United States)

    Pagourelias, Efstathios D.; Zorou, Paraskevi G.; Tsaligopoulos, Miltiadis; Athyros, Vasilis G.; Karagiannis, Asterios; Efthimiadis, Georgios K.

    2011-09-01

    Carbon dioxide (CO2) balneotherapy is a kind of remedy with a wide spectrum of applications which have been used since the Middle Ages. However, its potential use as an adjuvant therapeutic option in patients with cardiovascular disease is not yet fully clarified. We performed a thorough review of MEDLINE Database, EMBASE, ISI WEB of Knowledge, COCHRANE database and sites funded by balneotherapy centers across Europe in order to recognize relevant studies and aggregate evidence supporting the use of CO2 baths in various cardiovascular diseases. The three main effects of CO2 hydrotherapy during whole body or partial immersion, including decline in core temperature, an increase in cutaneous blood flow, and an elevation of the score on thermal sensation, are analyzed on a pathophysiology basis. Additionally, the indications and contra-indications of the method are presented in an evidence-based way, while the need for new methodologically sufficient studies examining the use of CO2 baths in other cardiovascular substrates is discussed.

  11. Carbon dioxide removal in gas treating processes

    Energy Technology Data Exchange (ETDEWEB)

    Lidal, H.

    1992-06-01

    The main contribution of this work is the development of a simple and reliable modelling technique on carbon dioxide removal describing the vapor-liquid equilibria of CO{sub 2} in aqueous alkanolamine solutions. By making use of measured pH data, the author has circumvented the problem of estimating interaction parameters, activity coefficients, and equilibrium constants in the prediction of vapor-liquid equilibria. The applicability of the model is best demonstrated on the tertiary amine system using MDEA. For this system, the VLE is accurately represented for temperatures in the range 25 to 140{sup o}C, for CO{sub 2} loadings from 0.001 to 1 mol/mol, and for amine molarities usually encountered in acid gas treating processes. The absorption of CO{sub 2} into solutions containing the sterically hindered amine AMP, is also well described by the model. The equilibrium of CO{sub 2} in mixed solvents containing a glycol (TEG,DEG) and an alkonolamine (MEA,DEA) has been measured at temperatures encountered in the absorption units. An equilibrium model has been developed for the CO{sub 2}/TEG/MEA system for estimation of CO{sub 2} partial pressures, covering loadings and temperatures for both absorption and desorption conditions. An important spin-off of the work described is that two new experimental set-ups have been designed and built. 154 refs., 38 figs., 22 tabs.

  12. Euthanasia of neonatal mice with carbon dioxide

    Science.gov (United States)

    Pritchett, K.; Corrow, D.; Stockwell, J.; Smith, A.

    2005-01-01

    Exposure to carbon dioxide (CO2) is the most prevalent method used to euthanize rodents in biomedical research. The purpose of this study was to determine the time of CO2 exposure required to euthanize neonatal mice (0 to 10 days old). Multiple groups of mice were exposed to 100% CO 2 for time periods between 5 and 60 min. Mice were placed in room air for 10 or 20 min after CO2 exposure, to allow for the chance of recovery. If mice recovered at one time point, a longer exposure was examined. Inbred and outbred mice were compared. Results of the study indicated that time to death varied with the age of the animals and could be as long as 50 min on the day of birth and differed between inbred and outbred mice. Institutions euthanizing neonatal mice with CO2 may wish to adjust their CO 2 exposure time periods according the age of the mice and their genetic background. Copyright 2005 by the American Association for Laboratory Animal Science.

  13. Carbon dioxide removal and the futures market

    Science.gov (United States)

    Coffman, D.'Maris; Lockley, Andrew

    2017-01-01

    Futures contracts are exchange-traded financial instruments that enable parties to fix a price in advance, for later performance on a contract. Forward contracts also entail future settlement, but they are traded directly between two parties. Futures and forwards are used in commodities trading, as producers seek financial security when planning production. We discuss the potential use of futures contracts in Carbon Dioxide Removal (CDR) markets; concluding that they have one principal advantage (near-term price security to current polluters), and one principal disadvantage (a combination of high price volatility and high trade volume means contracts issued by the private sector may cause systemic economic risk). Accordingly, we note the potential for the development of futures markets in CDR, but urge caution about the prospects for market failure. In particular, we consider the use of regulated markets: to ensure contracts are more reliable, and that moral hazard is minimised. While regulation offers increased assurances, we identify major insufficiencies with this approach—finding it generally inadequate. In conclusion, we suggest that only governments can realistically support long-term CDR futures markets. We note existing long-term CDR plans by governments, and suggest the use of state-backed futures for supporting these assurances.

  14. Suppressing bullfrog larvae with carbon dioxide

    Science.gov (United States)

    Gross, Jackson A.; Ray, Andrew; Sepulveda, Adam J.; Watten, Barnaby J.; Densmore, Christine L.; Layhee, Megan J.; Mark Abbey-Lambert,; ,

    2014-01-01

    Current management strategies for the control and suppression of the American Bullfrog (Lithobates catesbeianus = Rana catesbeiana Shaw) and other invasive amphibians have had minimal effect on their abundance and distribution. This study evaluates the effects of carbon dioxide (CO2) on pre- and prometamorphic Bullfrog larvae. Bullfrogs are a model organism for evaluating potential suppression agents because they are a successful invader worldwide. From experimental trials we estimated that the 24-h 50% and 99% lethal concentration (LC50 and LC99) values for Bullfrog larvae were 371 and 549 mg CO2/L, respectively. Overall, larvae that succumbed to experimental conditions had a lower body condition index than those that survived. We also documented sublethal changes in blood chemistry during prolonged exposure to elevated CO2. Specifically, blood pH decreased by more than 0.5 pH units after 9 h of exposure and both blood partial pressure of CO2 (pCO2) and blood glucose increased. These findings suggest that CO2 treatments can be lethal to Bullfrog larvae under controlled laboratory conditions. We believe this work represents the necessary foundation for further consideration of CO2 as a potential suppression agent for one of the most harmful invaders to freshwater ecosystems.

  15. Demographic change and carbon dioxide emissions.

    Science.gov (United States)

    O'Neill, Brian C; Liddle, Brant; Jiang, Leiwen; Smith, Kirk R; Pachauri, Shonali; Dalton, Michael; Fuchs, Regina

    2012-07-14

    Relations between demographic change and emissions of the major greenhouse gas carbon dioxide (CO(2)) have been studied from different perspectives, but most projections of future emissions only partly take demographic influences into account. We review two types of evidence for how CO(2) emissions from the use of fossil fuels are affected by demographic factors such as population growth or decline, ageing, urbanisation, and changes in household size. First, empirical analyses of historical trends tend to show that CO(2) emissions from energy use respond almost proportionately to changes in population size and that ageing and urbanisation have less than proportional but statistically significant effects. Second, scenario analyses show that alternative population growth paths could have substantial effects on global emissions of CO(2) several decades from now, and that ageing and urbanisation can have important effects in particular world regions. These results imply that policies that slow population growth would probably also have climate-related benefits. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Slurried solid media for simultaneous water purification and carbon dioxide removal from gas mixtures

    Science.gov (United States)

    Aines, Roger D.; Bourcier, William L.; Viani, Brian

    2013-01-29

    A slurried solid media for simultaneous water purification and carbon dioxide removal from gas mixtures includes the steps of dissolving the gas mixture and carbon dioxide in water providing a gas, carbon dioxide, water mixture; adding a porous solid media to the gas, carbon dioxide, water mixture forming a slurry of gas, carbon dioxide, water, and porous solid media; heating the slurry of gas, carbon dioxide, water, and porous solid media producing steam; and cooling the steam to produce purified water and carbon dioxide.

  17. System-Level Analysis Modeling of Impacts of Operation Schemes of Geologic Carbon Dioxide Storage on Deep Groundwater and Carbon Dioxide Leakage Risk

    Science.gov (United States)

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

    2013-12-01

    The objectives of this study are to predict quantitatively groundwater and carbon dioxide flow in deep saline sandstone aquifers under various carbon dioxide injection schemes (injection rate, injection period) and to analyze integratively impacts of such carbon dioxide injection schemes on deep groundwater (brine) and carbon dioxide leakage risk through abandoned wells or faults. In order to achieve the first objective, a series of process-level prediction modeling of groundwater and carbon dioxide flow in a deep saline sandstone aquifer under several carbon dioxide injection schemes was performed using a multiphase thermo-hydrological numerical model TOUGH2 (Pruess et al., 1999). The prediction modeling results show that the extent of carbon dioxide plume is significantly affected by such carbon dioxide injection schemes. In order to achieve the second objective, a series of system-level analysis modeling of deep groundwater and carbon dioxide leakage risk through an abandoned well or a fault under several carbon dioxide injection schemes was then performed using a brine and carbon dioxide leakage risk analysis model CO2-LEAK (Kim, 2012). The analysis modeling results show that the rates and amounts of deep groundwater and carbon dioxide leakage through an abandoned well or a fault increase as the carbon dioxide injection rate increases. However, the rates and amounts of deep groundwater and carbon dioxide leakage through an abandoned well or a fault decrease as the carbon dioxide injection period increases. These system-level analysis modeling results for deep groundwater and carbon dioxide leakage risk can be utilized as baseline data for establishing guidelines to mitigate anticipated environmental adverse effects on shallower groundwater systems (aquifers) when deep groundwater and carbon dioxide leakage occur. This work was supported by the Geo-Advanced Innovative Action (GAIA) Program funded by the Korea Environmental Industry and Technology Institute

  18. Two case of Carbon Dioxide Laser Treatment of Oral Leukoplakia

    OpenAIRE

    中嶌, 哲; 山田, 哲男; 矢ヶ崎, 崇; 植田, 章夫; 鹿毛, 俊孝; 千野, 武廣; 長谷川, 博雅

    1987-01-01

    Recently Carbon Dioxide Laser treatment has become more available as a method for oral and maxillofacial surgeons to apply in the treatment of soft tissue lesions in the oral cavity. This paper presents two cases of leukoplakia that were treated successfully with Carbon Dioxide Laser equipment, Opelaser-01. We consider that this treatment is one of the best choices for the superficially situated soft tissue lesion, such as leukoplakia.

  19. Tethered catalysts for the hydration of carbon dioxide

    Science.gov (United States)

    Valdez, Carlos A; Satcher, Jr., Joe H; Aines, Roger D; Wong, Sergio E; Baker, Sarah E; Lightstone, Felice C; Stolaroff, Joshuah K

    2014-11-04

    A system is provided that substantially increases the efficiency of CO.sub.2 capture and removal by positioning a catalyst within an optimal distance from the air-liquid interface. The catalyst is positioned within the layer determined to be the highest concentration of carbon dioxide. A hydrophobic tether is attached to the catalyst and the hydrophobic tether modulates the position of the catalyst within the liquid layer containing the highest concentration of carbon dioxide.

  20. Aesthetic Depigmentation of Gingival Smoker's Melanosis Using Carbon Dioxide Lasers

    OpenAIRE

    Luis Silva Monteiro; José Adriano Costa; Marco Infante da Câmara; Rui Albuquerque; Marco Martins; José Júlio Pacheco; Filomena Salazar; Fernando Figueira

    2015-01-01

    Melanic pigmentation results from melanin produced by the melanocytes present in the basal layer of the oral epithelium. One of the most common causes of oral pigmentation is smoker melanosis, a condition associated with the melanocyte stimulation caused by cigarette smoke. This paper aims to illustrate the use of a carbon dioxide laser in the removal of the gingival melanic pigmentation for aesthetic reasons in a 27-year-old female patient with history of a smoking habit. The carbon dioxide ...

  1. Use of carbon dioxide in underground natural gas storage processes

    Directory of Open Access Journals (Sweden)

    Nagy Stanislaw

    2006-10-01

    Full Text Available The possibility of use of carbon dioxide in gas storage processes is presented. The model of mixing process between CO2 and methane in porous media is given. The process of injection of carbon dioxide into a lower part of storage near the water –gas contact is modeled. The example of changes in the mixing zone is presented and discussed.

  2. Electrocatalytic reduction of carbon dioxide to carbon monoxide and methane at an immobilized cobalt protoporphyrin

    NARCIS (Netherlands)

    Shen, J.; Kortlever, R.; Kas, Recep; Mul, Guido; Koper, M.T.M.

    2015-01-01

    The electrochemical conversion of carbon dioxide and water into useful products is a major challenge in facilitating a closed carbon cycle. Here we report a cobalt protoporphyrin immobilized on a pyrolytic graphite electrode that reduces carbon dioxide in an aqueous acidic solution at relatively low

  3. Single and Mixed Gas Adsorption Equilibria of Carbon Dioxide/Methane on Activated Carbon

    NARCIS (Netherlands)

    van der Vaart, R.; van der Vaart, Rick; Huiskes, Cindy; Bosch, H.; Reith, T.

    2000-01-01

    Single gas adsorption isotherms of methane and carbon dioxide on micro-porous Norit RB1 activated carbon were determined in a gravimetric analyser in the temperature range of 292 to 349 K and pressures to 0.8 Mpa. Furthermore binary isotherms of carbon dioxide and methane mixtures were determined at

  4. Fixation of carbon dioxide into dimethyl carbonate over titanium-based zeolitic thiophene-benzimidazolate framework

    Science.gov (United States)

    A titanium-based zeolitic thiophene-benzimidazolate framework has been designed for the direct synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide. The developed catalyst activates carbon dioxide and delivers over 16% yield of DMC without the use of any dehydra...

  5. Beneficial Use of Carbon Dioxide in Precast Concrete Production

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Yixin [McGill Univ., Montreal, QC (Canada)

    2014-06-26

    The feasibility of using carbon dioxide as feedstock in precast concrete production is studied. Carbon dioxide reacts with calcium compounds in concrete, producing solid calcium carbonates in binding matrix. Two typical precast products are examined for their capacity to store carbon dioxide during the production. They are concrete blocks and fiber-cement panels. The two products are currently mass produced and cured by steam. Carbon dioxide can be used to replace steam in curing process to accelerate early strength, improve the long-term durability and reduce energy and emission. For a reaction within a 24-hour process window, the theoretical maximum possible carbon uptake in concrete is found to be 29% based on cement mass in the product. To reach the maximum uptake, a special process is developed to promote the reaction efficiency to 60-80% in 4-hour carbon dioxide curing and improve the resistance to freeze-thaw cycling and sulfate ion attack. The process is also optimized to meet the project target of $10/tCO2 in carbon utilization. By the use of self-concentrating absorption technology, high purity CO2 can be produced at a price below $40/t. With low cost CO2 capture and utilization technologies, it is feasible to establish a network for carbon capture and utilization at the vicinity of carbon sources. If all block produces and panel producers in United States could adopt carbon dioxide process in their production in place of steam, carbon utilization in these two markets alone could consume more than 2 Mt CO2/year. This capture and utilization process can be extended to more precast products and will continue for years to come.

  6. Carbonate buffering and metabolic controls on carbon dioxide in rivers

    Science.gov (United States)

    Stets, Edward G.; Butman, David; McDonald, Cory P.; Stackpoole, Sarah M.; DeGrandpre, Michael D.; Striegl, Robert G.

    2017-04-01

    Multiple processes support the significant efflux of carbon dioxide (CO2) from rivers and streams. Attribution of CO2 oversaturation will lead to better quantification of the freshwater carbon cycle and provide insights into the net cycling of nutrients and pollutants. CO2 production is closely related to O2 consumption because of the metabolic linkage of these gases. However, this relationship can be weakened due to dissolved inorganic carbon inputs from groundwater, carbonate buffering, calcification, and anaerobic metabolism. CO2 and O2 concentrations and other water quality parameters were analyzed in two data sets: a synoptic field study and nationwide water quality monitoring data. CO2 and O2 concentrations were strongly negatively correlated in both data sets (ρ = -0.67 and ρ = -0.63, respectively), although the correlations were weaker in high-alkalinity environments. In nearly all samples, the molar oversaturation of CO2 was a larger magnitude than molar O2 undersaturation. We used a dynamically coupled O2CO2 model to show that lags in CO2 air-water equilibration are a likely cause of this phenomenon. Lags in CO2 equilibration also impart landscape-scale differences in the behavior of CO2 between high- and low-alkalinity watersheds. Although the concept of carbonate buffering and how it creates lags in CO2 equilibration with the atmosphere is well understood, it has not been sufficiently integrated into our understanding of CO2 dynamics in freshwaters. We argue that the consideration of carbonate equilibria and its effects on CO2 dynamics are primary steps in understanding the sources and magnitude of CO2 oversaturation in rivers and streams.

  7. Carbonate buffering and metabolic controls on carbon dioxide in rivers

    Science.gov (United States)

    Stets, Edward; Butman, David; McDonald, Cory P.; Stackpoole, Sarah M.; DeGrandpre, Michael D.; Striegl, Rob

    2017-01-01

    Multiple processes support the significant efflux of carbon dioxide (CO2) from rivers and streams. Attribution of CO2 oversaturation will lead to better quantification of the freshwater carbon cycle and provide insights into the net cycling of nutrients and pollutants. CO2 production is closely related to O2consumption because of the metabolic linkage of these gases. However, this relationship can be weakened due to dissolved inorganic carbon inputs from groundwater, carbonate buffering, calcification, and anaerobic metabolism. CO2and O2 concentrations and other water quality parameters were analyzed in two data sets: a synoptic field study and nationwide water quality monitoring data. CO2 and O2 concentrations were strongly negatively correlated in both data sets (ρ = −0.67 and ρ = −0.63, respectively), although the correlations were weaker in high-alkalinity environments. In nearly all samples, the molar oversaturation of CO2 was a larger magnitude than molar O2 undersaturation. We used a dynamically coupled O2CO2 model to show that lags in CO2 air-water equilibration are a likely cause of this phenomenon. Lags in CO2 equilibration also impart landscape-scale differences in the behavior of CO2 between high- and low-alkalinity watersheds. Although the concept of carbonate buffering and how it creates lags in CO2 equilibration with the atmosphere is well understood, it has not been sufficiently integrated into our understanding of CO2 dynamics in freshwaters. We argue that the consideration of carbonate equilibria and its effects on CO2 dynamics are primary steps in understanding the sources and magnitude of CO2 oversaturation in rivers and streams.

  8. Enriching blast furnace gas by removing carbon dioxide.

    Science.gov (United States)

    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. Copyright © 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  9. Supercritical carbon dioxide for textile applications and recent developments

    Science.gov (United States)

    Eren, H. A.; Avinc, O.; Eren, S.

    2017-10-01

    In textile industry, supercritical carbon dioxide (scCO2), possessing liquid-like densities, mostly find an application on textile dyeing processes such as providing hydrophobic dyes an advantage on dissolving. Their gas-like low viscosities and diffusion properties can result in shorter dyeing periods in comparison with the conventional water dyeing process. Supercritical carbon dioxide dyeing is an anhydrous dyeing and this process comprises the usage of less energy and chemicals when compared to conventional water dyeing processes leading to a potential of up to 50% lower operation costs. The advantages of supercritical carbon dioxide dyeing method especially on synthetic fiber fabrics hearten leading textile companies to alter their dyeing method to this privileged waterless dyeing technology. Supercritical carbon dioxide (scCO2) waterless dyeing is widely known and applied green method for sustainable and eco-friendly textile industry. However, not only the dyeing but also scouring, desizing and different finishing applications take the advantage of supercritical carbon dioxide (scCO2). In this review, not only the principle, advantages and disadvantages of dyeing in supercritical carbon dioxide but also recent developments of scCO2 usage in different textile processing steps such as scouring, desizing and finishing are explained and commercial developments are stated and summed up.

  10. Measurement of carbon dioxide fluxes in a free-air carbon dioxide enrichment experiment using the closed flux chamber technique

    DEFF Research Database (Denmark)

    Selsted, Merete Bang; Ambus, Per; Michelsen, Anders

    2011-01-01

    Carbon dioxide (CO2) fluxes, composing net ecosystem exchange (NEE), ecosystem respiration (ER), and soil respiration (SR) were measured in a temperate heathland exposed to elevated CO2 by the FACE (free-air carbon enrichment) technique, raising the atmospheric CO2 concentration from c. 380 μmol...... concentration, and the flux also decreased in FACE plots, to 0.79 times that at low concentration. Similar SR in control plots was decreased 0.94 times in control plots and 0.88 times in FACE plots. We found that a useful method to achieve stable and reproducible chamber headspace and soil CO2 concentration...... prior to commencement of flux measurements was to turn off the FACE system at least 10 min in advance. Within 10 min a new equilibrium was established between the soil and atmosphere, apparently due to CO2 degassing from the top soil. The observed increase in SR in response to increased CO2 persisted...

  11. Carbon Dioxide Reduction Technology Trade Study

    Science.gov (United States)

    Jeng, Frank F.; Anderson, Molly S.; Abney, Morgan B.

    2011-01-01

    For long-term human missions, a closed-loop atmosphere revitalization system (ARS) is essential to minimize consumables. A carbon dioxide (CO2) reduction technology is used to reclaim oxygen (O2) from metabolic CO2 and is vital to reduce the delivery mass of metabolic O2. A key step in closing the loop for ARS will include a proper CO2 reduction subsystem that is reliable and with low equivalent system mass (ESM). Sabatier and Bosch CO2 reduction are two traditional CO2 reduction subsystems (CRS). Although a Sabatier CRS has been delivered to International Space Station (ISS) and is an important step toward closing the ISS ARS loop, it recovers only 50% of the available O2 in CO2. A Bosch CRS is able to reclaim all O2 in CO2. However, due to continuous carbon deposition on the catalyst surface, the penalties of replacing spent catalysts and reactors and crew time in a Bosch CRS are significant. Recently, technologies have been developed for recovering hydrogen (H2) from Sabatier-product methane (CH4). These include methane pyrolysis using a microwave plasma, catalytic thermal pyrolysis of CH4 and thermal pyrolysis of CH4. Further, development in Sabatier reactor designs based on microchannel and microlith technology could open up opportunities in reducing system mass and enhancing system control. Improvements in Bosch CRS conversion have also been reported. In addition, co-electrolysis of steam and CO2 is a new technology that integrates oxygen generation and CO2 reduction functions in a single system. A co-electrolysis unit followed by either a Sabatier or a carbon formation reactor based on Bosch chemistry could improve the overall competitiveness of an integrated O2 generation and CO2 reduction subsystem. This study evaluates all these CO2 reduction technologies, conducts water mass balances for required external supply of water for 1-, 5- and 10-yr missions, evaluates mass, volume, power, cooling and resupply requirements of various technologies. A system

  12. The role of renewable bioenergy in carbon dioxide sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, C.M. [Hawaii Natural Energy Inst., Honolulu, HI (United States)

    1993-12-31

    The use of renewable resources represents a sound approach to producing clean energy and reducing the dependence on diminishing reserves of fossil fuels. Unfortunately, the widespread interest in renewable energy in the 1970s, spurred by escalating fossil fuel prices, subsided with the collapse of energy prices in the mid 1980s. Today, it is largely to reverse alarming environmental trends, particularly the buildup of atmospheric carbon dioxide, rather than to reduce the cost of energy, that renewable energy resources are being pursued. This discussion focuses on a specific class of renewable energy resources - biomass. Unlike most other classes of renewable energy touted for controlling atmospheric carbon dioxide concentrations, e.g., hydro, direct solar, wind, geothermal, and ocean thermal, which produce usable forms of energy while generating little or no carbon dioxide emissions, bioenergy almost always involves combustion and therefore generates carbon dioxide; however, if used on a sustained basis, bio-energy would not contribute to the build-up of atmospheric carbon dioxide because the amount released in combustion would be balanced by that taken up via photosynthesis. It is in that context, i.e., sustained production of biomass as a modern energy carrier, rather than reforestation for carbon sequestration, that biomass is being discussed here, since biomass can play a much greater role in controlling global warming by displacing fossil fuels than by being used strictly for carbon sequestration (partly because energy crop production can reduce fossil carbon dioxide emissions indefinitely, whereas under the reforestation strategy, carbon dioxide abatement ceases at forest maturity).

  13. Optical carbon dioxide sensor based on fluorescent capillary array

    Directory of Open Access Journals (Sweden)

    Jian Wang

    Full Text Available A novel carbon dioxide (CO2 gas sensor based on capillary array is presented. The capillary array is composed of 51 capillaries and modified by fluorescent dye 8-hydroxy-1,3,6-pyrenetrisulfonic acid trisodium salt (HPTS, PTS− and tetraoctylammonium cation (TOA+ doped porous ethyl cellulose. A Y-fiber is used to transmit exciting light and fluorescence. A fiber optic pigtail-contained spectrophotometer is used to collect and deal with optical signals. Due to its structural features, each capillary has the two rolling-up layers of inner and outer sensing films, which make the 2 cm long capillary array has large sensing area about 12.81 cm2 and the fluorescence signal easily be collected. The sensing probe has advantages such as small volume, compact structure and large sensing area. The results demonstrate that the sensor has a linear response in the CO2 volume ratio range from 0 to 10%. Keywords: Carbon dioxide chemical sensor, Fluorescence sensor, Capillary array

  14. Stabilization of carbon dioxide and chromium slag via carbonation.

    Science.gov (United States)

    Wu, Xingxing; Yu, Binbin; Xu, Wei; Fan, Zheng; Wu, Zucheng; Zhang, Huimin

    2017-08-01

    As the main greenhouse gas, CO2 is considered as a threat in the context of global warming. Many available technologies to reduce CO2 emission was about CO2 separation from coal combustion and geological sequestration. However, how to deal with the cost-effective storage of CO2 has become a new challenge. Moreover, chromium pollution, the treatment of which requires huge energy consumption, has attracted people's widespread attention. This study is aimed to develop the sequestration of CO2 via chromium slag. A dynamic leaching experiment of chromium slag was designed to testify the ability of CO2 adsorption onto chromium slag and to release Cr(VI) for stabilization. The results showed that the accumulative amounts of Cr(VI) were ca. 2.6 mg/g released from the chromium slag after 24 h of leaching. In addition, ca. 89 mg/g CO2 was adsorbed by using pure CO2 in the experiment at 12 h. Calcite is the only carbonate species in the post-carbonated slag analyzed by powder X-ray diffraction and thermal analysis. The approach provides the feasibility of the utilization of chromium slag and sequestration of the carbon dioxide at the same time at ordinary temperatures and pressures.

  15. It is time to put carbon dioxide to work

    Energy Technology Data Exchange (ETDEWEB)

    Lipinsky, E.S. [Battelle, Columbus, OH (United States)

    1993-12-31

    The need to control emissions of carbon dioxide into the atmosphere is the subject of vigorous debate at this time. There is growing evidence that rising levels of carbon dioxide increase global warming, with perhaps highly adverse impacts for the human economy. There are calls for carbon taxes and other harsh measures. Japan has established a national goal of holding carbon dioxide emissions in the year 2000 to 1990 levels. I hope that this conference will be a turning point in the United States position on this issue. The current major end uses for CO{sub 2} include refrigeration, beverage carbonation, soda ash production, fire fighting, and urea fertilizer production. They are all based on chemistry that would not surprise a good chemist of the 19th century. Consumption of carbon dioxide in synthesis of industrial chemicals is limited. Usually one explains low production of chemicals from a candidate feedstock in terms of poor availability, price, purity, or reactivity. We can eliminate the first three as the causes of the underutilization of carbon dioxide.

  16. Carbon dioxide laser circumcisions for children.

    Science.gov (United States)

    How, A C S W; Ong, C C P; Jacobsen, A; Joseph, V T

    2003-04-01

    The carbon dioxide laser for circumcision was introduced by our department in 1989. This study aims to review our experience with laser circumcision for children and to evaluate its cost effectiveness as compared to conventional methods. A retrospective study of 30 patients who underwent conventional circumcision in 1985 and another 30 patients who underwent laser circumcision in 1995 was undertaken. The operating times in both groups were compared. The total cost of use of the laser machine was calculated, taking into account maintenance costs, estimated life span of laser machines (10 years) and costs of disposables used during each circumcision. This was weighed against the cost savings from shorter operating times and reduced operating theatre facility charges. Also, morbidity data from 2781 laser circumcisions done between May 1997 and April 2000 was collected. There was a significant decrease of 5 minutes in operating time for the group of patients who underwent laser circumcision. Calculated cost savings per laser circumcision from the reduced operating theatre time was S dollars 31/-. Of the 2781 cases of laser circumcision performed, there was an overall complication rate of 1.15%. Twenty-nine cases (1.04%) had post circumcision bleeding, of which 10 cases (0.36%) required unplanned return to operating theatre for hemostasis. Three cases (0.11%) had wound infection, requiring admission to hospital. Laser circumcision is a simple method with reduced operative time translating into cost effectiveness. Morbidity rates of laser circumcision compare favourably to those of conventional circumcision based on reports from other institutions.

  17. Carbon Dioxide Physiological Training at NASA.

    Science.gov (United States)

    Law, Jennifer; Young, Millennia; Alexander, David; Mason, Sara S; Wear, Mary L; Méndez, Claudia M; Stanley, David; Ryder, Valerie Meyers; Van Baalen, Mary

    2017-10-01

    Astronauts undergo CO2 exposure training to recognize their symptoms that can arise acutely both on the ground and in spaceflight. This article describes acute CO2 exposure training at NASA and examines the symptoms reported by astronauts during training. In a controlled training environment, astronauts are exposed to up to 8% CO2 (60 mmHg) by a rebreathing apparatus. Symptoms are reported using a standard form. Symptom documentation forms between April 1994 and February 2012 were obtained for 130 astronauts. The number of symptoms reported per session out of the possible 24 was related to age and sex, with those older slightly more likely to report symptoms. Women reported more symptoms on average than men (men: 3.7, women: 4.7). Respiratory symptoms (90%), flushing sensation/sweating (56%), and dizziness/feeling faint/lightheadedness (43%) were the top symptoms. Only headache reached statistical significance in differences between men (13%) and women (37%) after adjustment for multiple testing. Among those with multiple training sessions, respiratory symptoms were the most consistently reported. CO2 exposure training is an important tool to educate astronauts about their potential acute CO2 symptoms. Wide interindividual and temporal variations were observed in symptoms reported during astronaut CO2 exposure training. Headache could not be relied on as a marker of acute exposure during testing since fewer than half the subjects reported it. Our results support periodic refresher training since symptoms may change over time. Further study is needed to determine the optimal interval of training to maximize symptom recognition and inform operational decisions.Law J, Young M, Alexander D, Mason SS, Wear ML, Méndez CM, Stanley D, Meyers Ryder V, Van Baalen M. Carbon dioxide physiological training at NASA. Aerosp Med Hum Perform. 2017; 88(10):897-902.

  18. Deriving Algorithms for the Remote Sensing of Carbon Dioxide Fugacity at the Ocean Surface

    Science.gov (United States)

    Minnett, P. J.; Wickramaratna, K.; Kubat, M.

    2010-12-01

    As concentrations of carbon dioxide in the atmosphere continue to rise, the capacity of the ocean to act as a carbon dioxide sink is of critical importance as it is the major sink of anthropogenic carbon dioxide. Uncertainties in our ability to quantify the role of the oceans in the carbon cycle, especially in computing the gas fluxes between atmosphere and ocean on global scales, leads directly to uncertainty in predicting the response of the of the climate system to increasing levels of carbon dioxide in the atmosphere. Here we report on a study to improve the accuracy of the retrievals of surface fugacity from earth observation satellites. A large data set of in situ measurements from equipment on the Royal Caribbean Cruise Lines ship Explorer of the Seas in the Caribbean Sea and western tropical Atlantic Ocean the relationship between the carbon dioxide concentration and variables measurable from space is explored using advanced computational techniques to improve on prior results derived by linear regression. Using natural selection as a conceptual model, the Genetic Algorithm approach maintains a population of “tentative” solutions that are subjected to “survival of the fittest” tests and to operators that implement mutation and recombination (mutual exchange of the “genetic information”). In our implementation, each specimen in the population represents one formula, expressed by a tree-like data structure. The fitness function that quantifies the individual's survival chances is defined as the mean square error scored by the given formula on the training data. We demonstrate in this case study that not only can the accuracy of satellite retrievals of surface fugacity of carbon dioxide be improved by using algorithms based on the information content of the data sets, but also the regions in which individual algorithms are applicable can also be determined. These regions align with the underlying dynamical oceanographic features. This approach can

  19. Product selectivity in plasmonic photocatalysis for carbon dioxide hydrogenation

    National Research Council Canada - National Science Library

    Zhang, Xiao; Li, Xueqian; Zhang, Du; Su, Neil Qiang; Yang, Weitao; Everitt, Henry O; Liu, Jie

    2017-01-01

    ... and selectively producing a desired but kinetically unfavourable product for the important carbon dioxide hydrogenation reaction. Methane is almost exclusively produced when rhodium nanoparticles are mildly illuminated as hot electrons are injected into the anti-bonding orbital of a critical intermediate, while carbon monoxide and methane are equally produce...

  20. Capturing carbon dioxide as a polymer from natural gas.

    Science.gov (United States)

    Hwang, Chih-Chau; Tour, Josiah J; Kittrell, Carter; Espinal, Laura; Alemany, Lawrence B; Tour, James M

    2014-06-03

    Natural gas is considered the cleanest and recently the most abundant fossil fuel source, yet when it is extracted from wells, it often contains 10-20 mol% carbon dioxide (20-40 wt%), which is generally vented to the atmosphere. Efforts are underway to contain this carbon dioxide at the well-head using inexpensive and non-corrosive methods. Here we report nucleophilic porous carbons are synthesized from simple and inexpensive carbon-sulphur and carbon-nitrogen precursors. Infrared, Raman and (13)C nuclear magnetic resonance signatures substantiate carbon dioxide fixation by polymerization in the carbon channels to form poly(CO2) under much lower pressures than previously required. This growing chemisorbed sulphur- or nitrogen-atom-initiated poly(CO2) chain further displaces physisorbed hydrocarbon, providing a continuous carbon dioxide selectivity. Once returned to ambient conditions, the poly(CO2) spontaneously depolymerizes, leading to a sorbent that can be easily regenerated without the thermal energy input that is required for traditional sorbents.

  1. Assessing Carbon Dioxide Emissions from Energy Use at a University

    Science.gov (United States)

    Riddell, William; Bhatia, Krishan Kumar; Parisi, Matthew; Foote, Jessica; Imperatore, John, III

    2009-01-01

    Purpose: The purpose of this paper is to assess the carbon dioxide emissions associated with electric, HVAC, and hot water use from a US university. Design/methodology/approach: First, the total on-campus electrical, natural gas and oil consumption for an entire year was assessed. For each category of energy use, the carbon associated with…

  2. High‐temperature carbon dioxide capture using metal oxides

    OpenAIRE

    Vogt, Christian

    2017-01-01

    Carbon dioxide (CO2) emissions to the atmosphere are considered a significant contributor to climate change due to the activity of the carbon dioxide molecule in the infrared spectrum. This causes solar radiation to be ‘trapped’ in the earth’s atmosphere if increased CO2 concentrations are present, leading to global warming. In order to decrease CO2 emissions from stationary sources, like fossil fuel-fired power plants, and halt global warming, carbon capture and storage is proposed as a viab...

  3. Carbon dioxide flooding as an enhanced oil recovery process

    Energy Technology Data Exchange (ETDEWEB)

    Mungan, N. (Alberta Energy Co. Ltd., AB (Canada))

    1992-11-01

    A description is presented of the state-of-the-art on carbon dioxide flooding and how it relates to recovery of heavy oils. Carbon dioxide flooding enhances recovery due to a number of mechanisms: reduction of oil viscosity, swelling of oil, vaporization of oil, miscibility effects, reduction of interfacial tension, solution gas drive, and increases in injectivity. Three types of reservoir are particularly well suited to carbon dioxide flooding: carbonate formations which may not have a high enough injectivity to make waterflooding successful; reservoirs containing undersaturated crude oils; and certain heavy oil reservoirs. A detailed description is presented of preparation for a field test, pressure-volume-temperature data for light and heavy crude oils, and a pilot testing of CO[sub 2] flooding. To the extent that it is possible, the pilot should closely represent the formation and fluid properties and the pressures that exist in the reservoir. 7 refs., 4 figs.

  4. Sequestration of carbon dioxide with hydrogen to useful products

    Science.gov (United States)

    Adams, Michael W. W.; Kelly, Robert M.; Hawkins, Aaron B.; Menon, Angeli Lal; Lipscomb, Gina Lynette Pries; Schut, Gerrit Jan

    2017-03-07

    Provided herein are genetically engineered microbes that include at least a portion of a carbon fixation pathway, and in one embodiment, use molecular hydrogen to drive carbon dioxide fixation. In one embodiment, the genetically engineered microbe is modified to convert acetyl CoA, molecular hydrogen, and carbon dioxide to 3-hydroxypropionate, 4-hydroxybutyrate, acetyl CoA, or the combination thereof at levels greater than a control microbe. Other products may also be produced. Also provided herein are cell free compositions that convert acetyl CoA, molecular hydrogen, and carbon dioxide to 3-hydroxypropionate, 4-hydroxybutyrate, acetyl CoA, or the combination thereof. Also provided herein are methods of using the genetically engineered microbes and the cell free compositions.

  5. The Orbiting Carbon Observatory: NASA's First Dedicated Carbon Dioxide Mission

    Science.gov (United States)

    Crisp, D.

    2008-01-01

    The Orbiting Carbon Observatory is scheduled for launch from Vandenberg Air Force Base in California in January 2009. This Earth System Science Pathfinder (ESSP) mission carries and points a single instrument that incorporates 3 high-resolution grating spectrometers designed to measure the absorption of reflected sunlight by near-infrared carbon dioxide (CO2) and molecular oxygen bands. These spectra will be analyzed to retrieve estimates of the column-averaged CO2 dry air mole fraction, X(sub CO2). Pre-flight qualification and calibration tests completed in early 2008 indicate that the instrument will provide high quality X(sub CO2) data. The instrument was integrated into the spacecraft, and the completed Observatory was qualified and tested during the spring and summer of 2008, in preparation for delivery to the launch site in the fall of this year. The Observatory will initially be launched into a 635 km altitude, near-polar orbit. The on-board propulsion system will then raise the orbit to 705 km and insert OCO into the Earth Observing System Afternoon Constellation (A-Train). The first routine science observations are expected about 45 days after launch. Calibrated spectral radiances will be archived starting about 6 months later. An exploratory X(sub CO2) product will be validated and then archived starting about 3 months after that.

  6. Imaging of Carbon Translocation to Fruit Using Carbon-11-Labeled Carbon Dioxide and Positron Emission Tomography

    Science.gov (United States)

    Kawachi, Naoki; Kikuchi, Kaori; Suzui, Nobuo; Ishii, Satomi; Fujimaki, Shu; Ishioka, Noriko S.; Watabe, Hiroshi

    2011-04-01

    Carbon kinetics into the fruit is an agricultural issue on the growth and development of the sink organs to be harvested. Particularly, photoassimilate translocation and distribution are important topics for understanding the mechanism. In the present work, carbon-11 (11C) labeled photoassimilate translocation into fruits of tomato has been imaged using carbon-11-labeled carbon dioxide and the positron emission tomography (PET). Dynamice PET data of gradual increasing of 11C activity and its distribution is acquired quantitatively in intact plant body. This indicates that the 3-D photoassimilate translocation into the fruits is imaged successfully and carbon kinetics is analyzable to understand the plant physiology and nutrition.

  7. Multum in Parvo: Explorations with a Small Bag of Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    EJM Campbell

    2001-01-01

    Full Text Available A collection of 12 papers published between 1957 and 1972 are revisited. The papers had a common theme of the use of rebreathing carbon dioxide and explored a variety of topics in respiratory physiology. The first study established a method for the noninvasive and indirect estimation of arterial carbon dioxide pressure that was suitable for the routine clinical monitoring of respiratory failure and whose clinical utility remains to this day, but which also provided observations that were the stimulus for the studies that followed. The rate of rise in the partial pressure of carbon dioxide (PCO2 during rebreathing led to an analysis of body carbon dioxide storage capacity. Knowledge of carbon dioxide storage led to a method for quantifying lactate production in exercise without the need for blood sampling. The changes in ventilation that accompanied the increase in PCO2 provided the basis for a rapid method for measuring aspects of breathing control (Read's method, which was later modified to measure the ventilatory response to hypoxia. The physiology of breath-holding was explored through observations of the fall in breath-holding time as PCO2 climbed. Rebreathing also allowed increases in voluntary ventilation to be achieved without the development of alkalosis, leading to studies of maximal voluntary ventilation and respiratory muscle fatigue. Equilibration of PCO2 during rebreathing was used to measure mixed venous PCO2 during exercise and develop an integrated approach to the physiology of exercise in health and disease; alveolar-arterial disequilibrium in PCO2 during exercise was uncovered. Equilibration of PCO2, as well as PO2, during rebreathing of carbon dioxide and nitrogen gas mixtures showed different time courses of venous gases at the onset of exercise. Starting with the rebreathing of carbon dioxide in oxygen mixtures in a small rubber bag, an astonishing range of topics in respiratory physiology was explored, with observations

  8. Direct carbon dioxide emissions from civil aircraft

    Science.gov (United States)

    Grote, Matt; Williams, Ian; Preston, John

    2014-10-01

    Global airlines consume over 5 million barrels of oil per day, and the resulting carbon dioxide (CO2) emitted by aircraft engines is of concern. This article provides a contemporary review of the literature associated with the measures available to the civil aviation industry for mitigating CO2 emissions from aircraft. The measures are addressed under two categories - policy and legal-related measures, and technological and operational measures. Results of the review are used to develop several insights into the challenges faced. The analysis shows that forecasts for strong growth in air-traffic will result in civil aviation becoming an increasingly significant contributor to anthropogenic CO2 emissions. Some mitigation-measures can be left to market-forces as the key-driver for implementation because they directly reduce airlines' fuel consumption, and their impact on reducing fuel-costs will be welcomed by the industry. Other mitigation-measures cannot be left to market-forces. Speed of implementation and stringency of these measures will not be satisfactorily resolved unattended, and the current global regulatory-framework does not provide the necessary strength of stewardship. A global regulator with ‘teeth' needs to be established, but investing such a body with the appropriate level of authority requires securing an international agreement which history would suggest is going to be very difficult. If all mitigation-measures are successfully implemented, it is still likely that traffic growth-rates will continue to out-pace emissions reduction-rates. Therefore, to achieve an overall reduction in CO2 emissions, behaviour change will be necessary to reduce demand for air-travel. However, reducing demand will be strongly resisted by all stakeholders in the industry; and the ticket price-increases necessary to induce the required reduction in traffic growth-rates place a monetary-value on CO2 emissions of approximately 7-100 times greater than other common

  9. Inhibition of Frying Oil Oxidation by Carbon Dioxide Blanketing.

    Science.gov (United States)

    Totani, Nagao; Inoue, Ryota; Yawata, Miho

    2016-06-01

    The oxidation of oil starts, in general, from the penetration of atmospheric oxygen into oil. Inhibition of the vigorous oxidation of oil at deep-frying temperature under carbon dioxide flow, by disrupting the contact between oil and air, was first demonstrated using oil in a round bottom flask. Next, the minimum carbon dioxide flow rate necessary to blanket 4 L of frying oil in an electric fryer (surface area 690 cm(2)) installed with nonwoven fabric cover, was found to be 40 L/h. Then deep-frying of potato was done accordingly; immediately after deep-frying, an aluminum cover was placed on top of the nonwoven fabric cover to prevent the loss of carbon dioxide and the carbon dioxide flow was shut off. In conclusion, the oxidation of oil both at deep-frying temperature and during standing was remarkably inhibited by carbon dioxide blanketing at a practical flow rate and volume. Under the deep-frying conditions employed in this study, the increase in polar compound content was reduced to half of that of the control.

  10. Optical carbon dioxide sensor based on fluorescent capillary array

    Science.gov (United States)

    Wang, Jian; Wen, Zhihui; Yang, Bo; Yang, Xuefeng

    A novel carbon dioxide (CO2) gas sensor based on capillary array is presented. The capillary array is composed of 51 capillaries and modified by fluorescent dye 8-hydroxy-1,3,6-pyrenetrisulfonic acid trisodium salt (HPTS, PTS-) and tetraoctylammonium cation (TOA+) doped porous ethyl cellulose. A Y-fiber is used to transmit exciting light and fluorescence. A fiber optic pigtail-contained spectrophotometer is used to collect and deal with optical signals. Due to its structural features, each capillary has the two rolling-up layers of inner and outer sensing films, which make the 2 cm long capillary array has large sensing area about 12.81 cm2 and the fluorescence signal easily be collected. The sensing probe has advantages such as small volume, compact structure and large sensing area. The results demonstrate that the sensor has a linear response in the CO2 volume ratio range from 0 to 10%.

  11. A regional and global analysis of carbon dioxide physiological forcing and its impact on climate

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, Timothy; Forster, Piers M. [University of Leeds, Institute for Climate and Atmospheric Science, School of Earth and Environment, Leeds (United Kingdom); Doutriaux-Boucher, Marie; Boucher, Olivier [Met Office Hadley Centre, Exeter (United Kingdom)

    2011-02-15

    An increase in atmospheric carbon dioxide concentration has both a radiative (greenhouse) effect and a physiological effect on climate. The physiological effect forces climate as plant stomata do not open as wide under enhanced CO{sub 2} levels and this alters the surface energy balance by reducing the evapotranspiration flux to the atmosphere, a process referred to as 'carbon dioxide physiological forcing'. Here the climate impact of the carbon dioxide physiological forcing is isolated using an ensemble of twelve 5-year experiments with the Met Office Hadley Centre HadCM3LC fully coupled atmosphere-ocean model where atmospheric carbon dioxide levels are instantaneously quadrupled and thereafter held constant. Fast responses (within a few months) to carbon dioxide physiological forcing are analyzed at a global and regional scale. Results show a strong influence of the physiological forcing on the land surface energy budget, hydrological cycle and near surface climate. For example, global precipitation rate reduces by {proportional_to}3% with significant decreases over most land-regions, mainly from reductions to convective rainfall. This fast hydrological response is still evident after 5 years of model integration. Decreased evapotranspiration over land also leads to land surface warming and a drying of near surface air, both of which lead to significant reductions in near surface relative humidity ({proportional_to}6%) and cloud fraction ({proportional_to}3%). Patterns of fast responses consistently show that results are largest in the Amazon and central African forest, and to a lesser extent in the boreal and temperate forest. Carbon dioxide physiological forcing could be a source of uncertainty in many model predicted quantities, such as climate sensitivity, transient climate response and the hydrological sensitivity. These results highlight the importance of including biological components of the Earth system in climate change studies. (orig.)

  12. Helium enrichment during convective carbon dioxide dissolution

    Science.gov (United States)

    Larson, T.; Hesse, M. A.

    2013-12-01

    Motivated by observed variations of the CO2/He ratios in natural carbon dioxide (CO2) reservoirs, such as the Bravo Dome field in northeastern New Mexico, we have performed laboratory experiments equilibrating gas mixtures containing Helium (He) and CO2 with water, at close to ambient conditions in a closed system. The experimental design allows for continuous measurement of headspace pressure as well as timed interval measurements of the CO2/He ratios and the δ13C value of CO2 in the headspace. Results from three dissolution experiments are reported: 1) pure Helium system, 2) 98% CO2 + 2% Nitrogen system, and 3) 97% CO2 and 3% Helium. Final equilibrated experimental results are compared to theoretical results obtained using Henry's Law relationships. The evolution of the amount of dissolved CO2 computed from gas pressure and gas compositions are in good agreement with Henry's Law relationships. For example, the CO2 + N2 system was initially pressurized with pure CO2 to 1323 mbar and after six days it equilibrated to a measured headspace pressure of 596 mbar. This compares very well with a calculated equilibrium headspace pressure of 592 mbar for this system. The CO2 + He system was pressurized to 1398 mbar CO2 and after six days equilibrated to a measured headspace pressure of 397 mbar. This measured pressure is slightly higher than the predicted equilibrated headspace pressure of 341 mbar, indicating a possible leak in the system during this particular experiment. In both experiments the initial pH of the water was 9.3 and the final equilibrated pH was 5.4. The δ13C value of equilibrated headspace CO2 was within 0.25‰ of its starting δ13C value, demonstrating insignificant carbon isotope fractionation at low pH. Measured Helium/ CO2 ratios throughout the CO2+Helium experiment preserve a non-linear trend of increasing He/ CO2 ratios through time that correlate very well with the measured pressure drop from CO2 dissolution. This indicates that gas composition

  13. Carbon dioxide as a carbon source in organic transformation: carbon-carbon bond forming reactions by transition-metal catalysts.

    OpenAIRE

    Tsuji, Yasushi; Fujihara, Tetsuaki

    2012-01-01

    Recent carbon-carbon bond forming reactions of carbon dioxide with alkenes, alkynes, dienes, aryl zinc compounds, aryl boronic esters, aryl halides, and arenes having acidic C-H bonds are reviewed in which transition-metal catalysts play an important role.

  14. Molecular and physiological responses to titanium dioxide ...

    Science.gov (United States)

    - Changes in tissue transcriptomes and productivity of Arabidopsis thaliana were investigated during exposure of plants to two widely-used engineered metal oxide nanoparticles, titanium dioxide (nano-titanium) and cerium dioxide (nano-cerium). Microarray analyses confirmed that exposure to either nanoparticle altered the transcriptomes of rosette leaves and roots, with comparatively larger numbers of differentially expressed genes (DEGs) found under nano-titania exposure. Nano-titania induced more DEGs in rosette leaves, whereas roots had more DEGs under nano-ceria exposure. MapMan analyses indicated that while nano-titania up-regulated overall and secondary metabolism in both tissues, metabolic processes under nano-ceria remained mostly unchanged. Gene enrichment analysis indicated that both nanoparticles mainly enriched ontology groups such as responses to stress (abiotic and biotic), and defense responses (pathogens), and responses to endogenous stimuli (hormones). Nano-titania specifically induced genes associated with photosynthesis, whereas nano-ceria induced expression of genes related to activating transcription factors, most notably those belonging to the ethylene responsive element binding protein family. Interestingly, there were also increased numbers of rosette leaves and plant biomass under nano-ceria exposure, but not under nano-titania. Other transcriptomic responses did not clearly relate to responses observed at the organism level. This may b

  15. Aesthetic Depigmentation of Gingival Smoker's Melanosis Using Carbon Dioxide Lasers.

    Science.gov (United States)

    Monteiro, Luis Silva; Costa, José Adriano; da Câmara, Marco Infante; Albuquerque, Rui; Martins, Marco; Pacheco, José Júlio; Salazar, Filomena; Figueira, Fernando

    2015-01-01

    Melanic pigmentation results from melanin produced by the melanocytes present in the basal layer of the oral epithelium. One of the most common causes of oral pigmentation is smoker melanosis, a condition associated with the melanocyte stimulation caused by cigarette smoke. This paper aims to illustrate the use of a carbon dioxide laser in the removal of the gingival melanic pigmentation for aesthetic reasons in a 27-year-old female patient with history of a smoking habit. The carbon dioxide laser vaporisation was performed on the gingival mucosa with effective and quick results and without any complications or significant symptoms after the treatment. We conclude that a carbon dioxide laser could be a useful, effective, and safe instrument to treat the aesthetic complications caused by oral smoker melanosis.

  16. Using LMDI approach to analyze changes in carbon dioxide emissions of China’s logistics industry

    OpenAIRE

    Ying Dai; Jing Zhu; Han Song

    2015-01-01

    Purpose: China is confronting with tremendous pressure in carbon emission reduction. While logistics industry seriously relies on fossil fuel, and emits greenhouse gas, especially carbon dioxide. The aim of this article is to estimate the carbon dioxide emission in China’s logistics sector, and analyze the causes for the change of carbon dioxide emission, and identify the critical factors which mainly drive the change in carbon dioxide emissions of China’s logistics industry. Design/methodolo...

  17. Interaction of carbon dioxide with Cu overlayers on Pt(111)

    DEFF Research Database (Denmark)

    Schumacher, N.; Andersson, Klas Jerker; Grabow, L.C.

    2008-01-01

    Experimental and theoretical studies on the interaction of carbon dioxide with pseudomorphic and rough copper layers deposited on a platinum (111) single crystal are reported. Evidence for carbon dioxide dissociation and carbonate formation is presented and the relevance to methanol synthesis......) reveals a broad high temperature desorption state for CO2 with peak maximum around 450 K. X-ray photoelectron spectroscopy (XPS) shows that approximately one third of the oxygen accumulated on the surface upon CO2 exposure remains after TPD, indicative of carbonate formation via CO2 dissociation supplying...... O-ads and then facile CO2 + O-ads association, as well as subsequent decomposition at higher temperatures. Density functional theory studies of stepped Cu and Cu/Pt slabs reproduce vibrational frequencies of the carbonate, suggesting a nearly flat tridentate configuration at steps/defect sites....

  18. Alteration of Oceanic Nitrification Under Elevated Carbon Dioxide Concentrations

    Science.gov (United States)

    Beman, J.; Chow, C. E.; Popp, B. N.; Fuhrman, J. A.; Feng, Y.; Hutchins, D. A.

    2008-12-01

    Atmospheric carbon dioxide (CO2) concentrations are increasing exponentially and expected to double by the year 2100. Dissolution of excess CO2 in the upper ocean reduces pH, alters carbonate chemistry, and also represents a potential resource for autotrophic organisms that convert inorganic carbon into biomass--including a broad spectrum of marine microbes. These bacteria and archaea drive global biogeochemical cycles of carbon and nitrogen and constitute the vast majority of biomass in the sea, yet their responses to reduced pH and increased pCO2 remain largely undocumented. Here we show that elevated pCO2 may sharply reduce nitrification rates and populations of nitrifying microorganisms in the ocean. Multiple experiments were performed in the Sargasso Sea and the Southern California Bight under glacial maximum (193 ppm), present day (390 ppm), and projected (750 ppm) pCO2 concentrations, over time scales from hours to multiple days, and at depths of 45 m to 240 m. Measurement of nitrification rates using isotopically-labeled nitrogen showed 2-5 fold reduction under elevated pCO2--as well as an increase under glacial maximum pCO2. Marine Crenarchaeota are likely involved in nitrification as ammonia-oxidizing archaea (AOA) and are among the most abundant microbial groups in the ocean, yet this group decreased by 40-80% under increased pCO2, based on quantification of both 16S rRNA and ammonia monooxygenase (amoA) gene copies. Crenarchaeota also steadily declined over the course of multiple days under elevated pCO2, whereas ammonia-oxidizing (AOB) and nitrite-oxidizing bacteria (NOB) were more variable in their responses or were not detected. These findings suggest that projected increases in pCO2 and subsequent decreases in pH may strongly influence marine biogeochemistry and microbial community structure in the sea.

  19. Optimization of enzymatic biodiesel synthesis using RSM in high pressure carbon dioxide and its scale up.

    Science.gov (United States)

    Lee, Myunggu; Lee, Dohoon; Cho, Jaehoon; Lee, Junhac; Kim, Sangyong; Kim, Seung Wook; Park, Chulhwan

    2013-06-01

    Enzymatic synthesis of biodiesel by the transesterification of canola oil and methanol in high pressure carbon dioxide [HPCO(2): near-critical and supercritical carbon dioxide (NcCO(2) and ScCO(2))] was optimized using response surface methodology (RSM). RSM based on 5-level-5-factor central composite rotatable design (CCRD) was used to evaluate the effects of temperature, pressure, enzyme loading, substrate molar ratio, and time on the conversion to biodiesel by transesterification. Finally, batch reactions for biodiesel synthesis were preformed in a 100 mL and 7 L high-pressure stirred batch reactors.

  20. Visual and reversible carbon dioxide sensing enabled by doctor blade coated macroporous photonic crystals.

    Science.gov (United States)

    Lin, Yi-Han; Suen, Shing-Yi; Yang, Hongta

    2017-11-15

    With significant impacts of carbon dioxide on global climate change, carbon dioxide sensing is of great importance. However, most of the existing sensing technologies are prone to interferences from carbon monoxide, or suffer from the use of sophisticated instruments. This research reports the development of reproducible carbon dioxide sensor using roll-to-roll compatible doctor blade coated three-dimensional macroporous photonic crystals. The pores are functionalized with amine groups to allow the reaction with carbon dioxide in the presence of humidity. The adsorption of carbon dioxide leads to red-shift and amplitude reduction of the optical stop bands, resulting in carbon dioxide detection with visible readout. The dependences of the diffraction wavelength on carbon dioxide partial pressure for various amine-functionalized photonic crystals and different humidities in the environment are systematically investigated. In addition, the reproducibility of carbon dioxide sensing has also been demonstrated in this research. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. 75 FR 29534 - Inorganic Nitrates-Nitrite, Carbon and Carbon Dioxide, and Sulfur Registration Review; Draft...

    Science.gov (United States)

    2010-05-26

    ...] [FR Doc No: 2010-12591] ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OPP-2010-0434; FRL-8826-6] Inorganic... ecological risk assessment for the registration review of inorganic nitrates - nitrites, carbon and carbon... inorganic nitrates- nitrites, carbon and carbon dioxide uses, as well as gas cartridge uses of sulfur. The...

  2. Supercritical carbon dioxide drying of methanol-Zinc borate mixtures

    OpenAIRE

    Gönen, Mehmet; Balköse, Devrim; Gupta, Ram B.; Ülkü, Semra

    2009-01-01

    Supercritical carbon dioxide (CO 2) drying of zinc borate species was investigated to evaluate possible chemical alterations in the product during the drying. Methanol-wetted zinc borates produced either from borax decahydrate and zinc nitrate hexahydrate (2ZnO · 3B 2O 3 ·7H 2O) or from zinc oxide and boric acid (2ZnO · 3B 2O 3 ·3H 2O) were dried by both conventional and supercritical carbon dioxide drying methods. Zinc borate samples dried by both techniques were characterized using analytic...

  3. Supercritical carbon dioxide-based sterilization of decellularized heart valves.

    Science.gov (United States)

    Hennessy, Ryan S; Jana, Soumen; Tefft, Brandon J; Helder, Meghana R; Young, Melissa D; Hennessy, Rebecca R; Stoyles, Nicholas J; Lerman, Amir

    2017-02-01

    The goal of this research project encompasses finding the most efficient and effective method of decellularized tissue sterilization. Aortic tissue grafts have been utilized to repair damaged or diseased valves. Although, the tissues for grafting are collected aseptically, it does not eradicate the risk of contamination nor disease transfer. Thus, sterilization of grafts is mandatory. Several techniques have been applied to sterilize grafts; however, each technique shows drawbacks. In this study, we compared several sterilization techniques: supercritical carbon dioxide, electrolyzed water, gamma radiation, ethanol-peracetic acid, and hydrogen peroxide for impact on the sterility and mechanical integrity of porcine decellularized aortic valves. Valve sterility was characterized by histology, microbe culture, and electron microscopy. Uniaxial tensile testing was conducted on the valve cusps along their circumferential orientation to study these sterilization techniques on their integrity. Ethanol-peracetic acid and supercritical carbon dioxide treated valves were found to be sterile. The tensile strength of supercritical carbon dioxide treated valves (4.28 ± 0.22 MPa) was higher to those valves treated with electrolyzed water, gamma radiation, ethanol-peracetic acid and hydrogen peroxide (1.02 ± 0.15, 1.25 ± 0.25, 3.53 ± 0.41 and 0.37 ± 0.04 MPa, respectively). Superior sterility and integrity were found in the decellularized porcine aortic valves with supercritical carbon dioxide sterilization. This sterilization technique may hold promise for other decellularized soft tissues. Sterilization of grafts is essential. Supercritical carbon dioxide, electrolyzed water, gamma radiation, ethanol-peracetic acid, and hydrogen peroxide techniques were compared for impact on sterility and mechanical integrity of porcine decellularized aortic valves. Ethanol-peracetic acid and supercritical carbon dioxide treated valves were found to be sterile using histology, microbe

  4. Carbon dioxide capture and storage : hindrances for implementation in Norway

    OpenAIRE

    Houm, Marius

    2007-01-01

    This paper is an actor-network theory-based analysis of the hindrances for implementation of carbon dioxide capture, transport and storage, CCS, as a climate mitigation initiative in Norway. It uses the Norwegian projects Kårstø, Mongstad, Tjeldbergodden/Halten/Draugen, Sleipner and Snøhvit as the basis for a discussion of the relevant technologies, obstacles, policies, rhetoric and realities. CCS is a possible way to reduce emissions of carbon dioxide. We need an emission reduction of th...

  5. Solubility of anthracene and anthraquinone in cyclohexanone + carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Chang, C.J. (National Chung-Hsing Univ., Taichung (Taiwan, Province of China). Dept. of Chemical Engineering)

    1994-10-01

    In the processing of an anthracene oil fraction from coal tar, a mixture of anthracene and anthraquinone is required to be separated to obtain products of high purity. The solubilities of anthracene and anthraquinone were measured in cyclohexanone + carbon dioxide as a function of the temperature and pressure of carbon dioxide at 291, 300, and 313 K and from 1.8--12.4 MPa. Average equilibrium solubilities and recoveries of both solids increased with increasing normalized concentration and pressure. The average separation factor of anthracene to anthraquinone, due to the effect of the mixed solvent, was 2.88 [+-] 1.91.

  6. The anaesthesia of fish by high carbon-dioxide concentrations

    Science.gov (United States)

    1942-01-01

    A practical and economical method for anaesthetizing adult salmon and steelhead trout in the fish trucks used in the Grand Coulee fish salvage program is described. The method consists in generating a predetermined carbon-dioxide concentration in the 1000-gallon tanks of the trucks through the successive addition of predissolved sodium bicarbonate and dilute sulphuric acid in proper quantities. Carbon-dioxide anaesthesia effectively solved the acute problem of species segregation in the fish salvage program and, with minor modifications, could be used with equal success in certain hatchery operations necessitating the handling of large fish.

  7. Kinetic study of coals gasification into carbon dioxide atmosphere

    Directory of Open Access Journals (Sweden)

    Korotkikh A.G.

    2015-01-01

    Full Text Available The solid fuel gasification process was investigated to define chemical reactions rate and activation energy for a gas-generator designing and regime optimizing. An experimental procedure includes coal char samples of Kuznetskiy and Kansko-Achinskiy deposits consequent argon pyrolysis into argon and oxidating into carbon dioxide with different temperatures. The thermogravimetric analysis data of coal char gasification into carbon dioxide was obtained in the temperature range 900–1200 ºC. The mass loss and gasification time dependencies from temperature were defined to calculate chemical reaction frequency factor and activation energy. Two coal char gasification physico-mathematical models were proposed and recommendations for them were formed.

  8. Flexible substrates as basis for photocatalytic reduction of carbon dioxide

    DEFF Research Database (Denmark)

    Jensen, Jacob; Mikkelsen, Mette; Krebs, Frederik C

    2011-01-01

    A photocatalytic system for converting carbon dioxide into carbon monoxide was designed and constructed. The system relies on thin films of the photocatalyst prepared at low temperature using spray coating. We formulated inks based on the well-known photocatalyst titanium dioxide and characterized...... the performance in this setting. Glass substrates were used for model studies with an active area of 100cm2 and flexible substrates based on polyethyleneterphthalate (PET), polyethylenenaphtalate (PEN) and polyethylene (PE) with a similar area for prototypes of photocatalytic converters. The results from this new...

  9. Social acceptance of carbon dioxide storage

    Energy Technology Data Exchange (ETDEWEB)

    Huijts, Nicole M.A.; Midden, Cees J.H.; Meijnders, Anneloes L. [Department of Technology Management, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

    2007-05-15

    This article discusses public acceptance of carbon capture and storage (CCS). Responses by citizens are described in relation to responses by professionally involved actors. Interviews with members of the government, industry and environmental NGOs showed that these professional actors are interested in starting up storage projects, based on thorough evaluation processes, including discussions on multi-actor working groups. As appeared from a survey among citizens living near a potential storage site (N=103), public attitudes in general were slightly positive, but attitudes towards storage nearby were slightly negative. The general public appeared to have little knowledge about CO{sub 2}-storage, and have little desire for more information. Under these circumstances, trust in the professional actors is particularly important. NGOs were found to be trusted most, and industry least by the general public. Trust in each of the three actors appeared to depend on perceived competence and intentions, which in turn were found to be related to perceived similarity of goals and thinking between trustee and trustor. Implications for communication about CCS are discussed. (author)

  10. Classroom Demonstration: Combustion of Diamond to Carbon Dioxide Followed by Reduction to Graphite

    Science.gov (United States)

    Miyauchi, Takuya; Kamata, Masahiro

    2012-01-01

    An educational demonstration shows the combustion of carbon to carbon dioxide and then the reduction of carbon dioxide to carbon. A melee diamond is the source of the carbon and the reaction is carried out in a closed flask. The demonstration helps students to realize that diamonds are made of carbon and that atoms do not change or vanish in…

  11. Energy Saving High-Capacity Moderate Pressure Carbon Dioxide Storage System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Our approach to high-pressure carbon dioxide storage will directly address the challenges associated with storage of compressed carbon dioxide - the need to reduce...

  12. Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends report is the authoritative reference for carbon dioxide (CO2) emissions,...

  13. Accuracy of Transcutaneous Carbon Dioxide Tension Measurements during Cardiopulmonary Exercise Testing

    National Research Council Canada - National Science Library

    Stege, Gerben; van den Elshout, Frank J.J; Heijdra, Yvonne F; van de Ven, Marjo J.T; Dekhuijzen, P.N. Richard; Vos, Petra J.E

    2009-01-01

    Background: Measurements of transcutaneous carbon dioxide tension (PtcCO ) with current devices are proven to provide clinically acceptable agreement with measurements of partial arterial carbon dioxide tension (PaCO...

  14. Microbial carbon dioxide fixation: new tricks for an old game.

    Science.gov (United States)

    Branduardi, Paola; Sauer, Michael

    2017-12-06

    The exploitation of petroleum as energy and material source opened unprecedented possibilities for the development of our human societies, but only now we realize that the use of fossil resources comes at devastatingly high environmental costs. Consequently, our efforts to tap other carbon sources are steadily increasing. Industrial microbiology has the potential to use carbon dioxide directly as carbon source, thereby converting a foe into a friend. This thematic issue of FEMS Microbiology Letters sheds some light on recent developments for the understanding of microbial pathways for carbon dioxide fixation and on strategies for their industrial exploitation. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Somewhere beyond the sea? The oceanic - carbon dioxide - reactions

    Science.gov (United States)

    Meisinger, Philipp; Wittlich, Christian

    2014-05-01

    In correlation to climate change and CO2 emission different campaigns highlight the importance of forests and trees to regulate the concentration of carbon dioxide in the earths' atmosphere. Seeing millions of square miles of rainforest cut down every day, this is truly a valid point. Nevertheless, we often tend to forget what scientists like Spokes try to raise awareness for: The oceans - and foremost deep sea sections - resemble the second biggest deposit of carbon dioxide. Here carbon is mainly found in form of carbonate and hydrogen carbonate. The carbonates are needed by corals and other sea organisms to maintain their skeletal structure and thereby to remain vital. To raise awareness for the protection of this fragile ecosystem in schools is part of our approach. Awareness is achieved best through understanding. Therefore, our approach is a hands-on activity that aims at showing students how the carbon dioxide absorption changes in relation to the water temperature - in times of global warming a truly sensitive topic. The students use standard syringes filled with water (25 ml) at different temperatures (i.e. 10°C, 20°C, 40°C). Through a connector students inject carbon dioxide (25ml) into the different samples. After a fixed period of time, students can read of the remaining amount of carbon dioxide in relation to the given water temperature. Just as with every scientific project, students need to closely monitor their experiments and alter their setups (e.g. water temperature or acidity) according to their initial planning. A digital template (Excel-based) supports the analysis of students' experiments. Overview: What: hands-on, minds -on activity using standard syringes to exemplify carbon dioxide absorption in relation to the water temperature (Le Chatelier's principle) For whom: adjustable from German form 11-13 (age: 16-19 years) Time: depending on the prior knowledge 45-60 min. Sources (extract): Spokes, L.: Wie Ozeane CO2 aufnehmen. Environmental

  16. Differential responses of net ecosystem exchange of carbon dioxide to light and temperature between spring and neap tides in subtropical mangrove forests.

    Science.gov (United States)

    Li, Qing; Lu, Weizhi; Chen, Hui; Luo, Yiqi; Lin, Guanghui

    2014-01-01

    The eddy flux data with field records of tidal water inundation depths of the year 2010 from two mangroves forests in southern China were analyzed to investigate the tidal effect on mangrove carbon cycle. We compared the net ecosystem exchange (NEE) and its responses to light and temperature, respectively, between spring tide and neap tide inundation periods. For the most time of the year 2010, higher daytime NEE values were found during spring tides than during neap tides at both study sites. Regression analysis of daytime NEE to photosynthetically active radiation (PAR) using the Landsberg model showed increased sensitivity of NEE to PAR with higher maximum photosynthetic rate during spring tides than neap tides. In contrast, the light compensation points acquired from the regression function of the Landsberg model were smaller during spring tides than neap tides in most months. The dependence of nighttime NEE on soil temperature was lower under spring tide than under neap tides. All these results above indicated that ecosystem carbon uptake rates of mangrove forests were strengthened, while ecosystem respirations were inhibited during spring tides in comparison with those during neap tides, which needs to be considered in modeling mangrove ecosystem carbon cycle under future sea level rise scenarios.

  17. Differential Responses of Net Ecosystem Exchange of Carbon Dioxide to Light and Temperature between Spring and Neap Tides in Subtropical Mangrove Forests

    Directory of Open Access Journals (Sweden)

    Qing Li

    2014-01-01

    Full Text Available The eddy flux data with field records of tidal water inundation depths of the year 2010 from two mangroves forests in southern China were analyzed to investigate the tidal effect on mangrove carbon cycle. We compared the net ecosystem exchange (NEE and its responses to light and temperature, respectively, between spring tide and neap tide inundation periods. For the most time of the year 2010, higher daytime NEE values were found during spring tides than during neap tides at both study sites. Regression analysis of daytime NEE to photosynthetically active radiation (PAR using the Landsberg model showed increased sensitivity of NEE to PAR with higher maximum photosynthetic rate during spring tides than neap tides. In contrast, the light compensation points acquired from the regression function of the Landsberg model were smaller during spring tides than neap tides in most months. The dependence of nighttime NEE on soil temperature was lower under spring tide than under neap tides. All these results above indicated that ecosystem carbon uptake rates of mangrove forests were strengthened, while ecosystem respirations were inhibited during spring tides in comparison with those during neap tides, which needs to be considered in modeling mangrove ecosystem carbon cycle under future sea level rise scenarios.

  18. Effect of dissolved carbon dioxide on penicillin fermentations: mycelial growth and penicillin production. [Penicillium chrysogenum

    Energy Technology Data Exchange (ETDEWEB)

    Ho, C.S.; Smith, M.D.

    1986-01-01

    The effect of dissolved carbon dioxide on the specific growth rate and the penicillin production rate of Penicillium chrysogenum was examined experimentally. The dissolved carbon dioxide was found to inhibit the specific growth rate and the penicillin production rate when the aerated submerged penicillin fermentation was exposed to influent gases of 12.6 and 20% carbon dioxide, respectively. Upon exposure to influent gases of 3 and 5% carbon dioxide, no pronounced metabolic inhibition was noted.

  19. Carbon dioxide inhalation induces dose-dependent and age-related negative affectivity.

    Directory of Open Access Journals (Sweden)

    Eric J Griez

    Full Text Available BACKGROUND: Carbon dioxide inhalation is known to induce an emotion similar to spontaneous panic in Panic Disorder patients. The affective response to carbon dioxide in healthy subjects was not clearly characterized yet. METHODOLOGY/PRINCIPAL FINDINGS: Sixty-four healthy subjects underwent a double inhalation of four mixtures containing respectively 0, 9, 17.5 and 35% CO(2 in compressed air, following a double blind, cross-over, randomized design. Affective responses were assessed according to DSM IV criteria for panic, using an Electronic Visual Analogue Scale and the Panic Symptom List. It was demonstrated that carbon dioxide challenges induced a dose dependent negative affect (p<0.0001. This affect was semantically identical to the DSM IV definition of panic. Older individuals were subjectively less sensitive to Carbon Dioxide (p<0.05. CONCLUSIONS/SIGNIFICANCE: CO(2 induced affectivity may lay on a continuum with pathological panic attacks. Consistent with earlier suggestions that panic is a false biological alarm, the affective response to CO(2 may be part of a protective system triggered by suffocation and acute metabolic distress.

  20. Carbon Dioxide Capture from Flue Gas Using Dry, Regenerable Sorbents

    Energy Technology Data Exchange (ETDEWEB)

    David A. Green; Thomas O. Nelson; Brian S. Turk; Paul D. Box; Raghubir P. Gupta

    2006-03-31

    This report describes research conducted between January 1, 2006, and March 31, 2006, on the use of dry regenerable sorbents for removal of carbon dioxide (CO{sub 2}) from coal combustion flue gas. An integrated system composed of a downflow co-current contact absorber and two hollow screw conveyors (regenerator and cooler) was assembled, instrumented, debugged, and calibrated. A new batch of supported sorbent containing 15% sodium carbonate was prepared and subjected to surface area and compact bulk density determination.

  1. CARBON-DIOXIDE LASER VAPORIZATION IN EARLY GLOTTIC CARCINOMA

    NARCIS (Netherlands)

    MAHIEU, HF; PATEL, P; ANNYAS, AA

    Objective: Presently, widely employed treatment modalities for early glottic carcinoma include radiation therapy, surgical excision, and carbon dioxide laser excision. All these treatments have good oncological results, but poor or questionable functional-results in terms of quality of voice and

  2. Carbon Dioxide Absorption in a Membrane Contactor with Color Change

    Science.gov (United States)

    Pantaleao, Ines; Portugal, Ana F.; Mendes, Adelio; Gabriel, Joaquim

    2010-01-01

    A pedagogical experiment is described to examine the physical absorption of gases, in this case carbon dioxide, in a hollow fiber membrane contactor (HFMC) where the absorption concentration profile can be followed by a color change. The HFMC is used to teach important concepts and can be used in interesting applications for students, such as…

  3. Design of Stable Catalysts for Methane-Carbon Dioxide Reforming

    NARCIS (Netherlands)

    Seshan, K.; Bitter, J.H.; Lercher, J.A.

    1998-01-01

    PtZrO2 is an active and stable catalyst for methane- carbon dioxide reforming reaction. The reaction between CO2 and CH4 to yield synthesis gas might proceed vie two different pethways. At high temperatures (>1075K) CO2 can be dissociated on Pt to CO and absorbed oxygen. Methane can be dissociated

  4. Electrochemical carbon dioxide reduction on rough copper surfaces

    NARCIS (Netherlands)

    Kas, Recep

    2016-01-01

    Sustainable development and climate change is considered to be one of the top challenges of humanity. Electrochemical carbon dioxide (CO2) reduction to fuels or fuel precursor using renewable electricity is a very promising way to recycle CO2 and store the electricity. This would also provide

  5. Carbon dioxide detection with polyethylenimine blended with polyelectrolytes

    NARCIS (Netherlands)

    Doan, T.C.D.; Baggerman, J.; Ramaneti, R.; Tong, H.D.; Marcelis, A.T.M.; Rijn, van C.J.M.

    2014-01-01

    Branched polyethylenimine (PEI) is studied for use as a chemiresistor for detection of carbon dioxide(CO2) at room temperature. The DC and AC measurements of drop-coated PEI films on interdigitated electrodes revealed a noticeable decrease in conductivity upon exposure to CO2 (400–2000 ppm)

  6. Risk mitigation strategies and policy implications for carbon dioxide ...

    African Journals Online (AJOL)

    USER

    Risk mitigation strategies and policy implications for carbon dioxide (CO2) emission in ... 1National Centre for Technology Management (NACETEM), Federal Ministry of Science and Technology,. Obafemi Awolowo University ..... needs assessment report under project: climate change enabling activity (Phase II). Republic of ...

  7. Solubilities of ferrocene and acetylferrocene in supercritical carbon dioxide

    DEFF Research Database (Denmark)

    Kazemi, Somayeh; Belandria, Veronica; Janssen, Nico

    2012-01-01

    In this work, the solubilities of ferrocene and acetylferrocene in supercritical carbon dioxide (scCO2) were measured using an analytical method in a quasi-flow apparatus. High-performance liquid chromatography was applied through an online sampling procedure to determine the concentration...

  8. Extraction of Coal-tar Pitch by Supercritical Carbon Dioxide ...

    African Journals Online (AJOL)

    Several extractions of coal-tar pitch were performed using supercritical fluid carbon dioxide. The relationships between extraction yield during supercritical fluid extraction (SFE) and the variables temperature, pressure and extraction time were investigated. For qualitative and quantitative identification of organic compounds, ...

  9. Quantitative aspects of oxygen and carbon dioxide exchange ...

    African Journals Online (AJOL)

    Quantitative aspects of oxygen and carbon dioxide exchange through the lungs in Ocypode ceratophthalmus (Crustacea: Decapoda) during rest and exercise in water ... The percent accumulated 14-CO2 in exhaled air, plotted against time, intersects zero time on the x-axis, indicating rapid gas exchange at the lung surface.

  10. Regulation of carbon dioxide fixation in the chemoautotroph Xanthobacter flavus

    NARCIS (Netherlands)

    Keulen, Geertje van

    2000-01-01

    Autotrophic bacteria and plants are able to convert the greenhouse gas carbon dioxide, CO2, into cell material. Although there are a number of metabolic pathways supporting autotrophic growth, the Calvin cycle is the most widely distributed of these. CO2 fixation requires a large amount of energy

  11. Carbon Dioxide Emissions Reduction Estimates: Potential Use of ...

    African Journals Online (AJOL)

    User

    UNIVERSITY OF MAURITIUS RESEARCH JOURNAL – Volume 16 – 2010. University of Mauritius, Réduit, Mauritius. Research Week 2009/2010. 512. Carbon Dioxide Emissions Reduction. Estimates: Potential Use of Biofuels in. Mauritian Transport Sector for Cars and Dual. Cars. D Surroop *. Faculty of Engineering,.

  12. Carbon dioxide, water vapour and energy fluxes over a semi ...

    Indian Academy of Sciences (India)

    42

    Key words: Eddy covariance; semi-evergreen forest; surface energy balance; Carbon dioxide. 25 flux; Indian .... following forest types and biomes (Champion and Seth 1968), namely Eastern wet alluvial. 86 grasslands ..... Turbulence characteristics of the site were analyzed (table 2 a-b)during whole period. 197 and four ...

  13. Reducing Carbon Dioxide Emissions: Using the Mole Concept.

    Science.gov (United States)

    Myers, Alan

    2002-01-01

    Provides an application of quantitative chemistry concepts in the context of motor vehicle emissions. Shows how carbon dioxide emissions from cars may be reduced by up to 25% by reducing motorway speeds from 70-75 mph to 60 mph. (Author/MM)

  14. SCATTERING OF CARBON-DIOXIDE MOLECULES FROM PD(111) SURFACES

    NARCIS (Netherlands)

    SCHLATHOLTER, T; HEILAND, W; Schlathölter, Thomas

    1995-01-01

    Carbon dioxide positive ions and neutral molecules are subject to different charge exchange processes when scattered off clean or potassium-covered Pd(111) surfaces under grazing incidence. The time-of-flight method is a suitable tool to investigate these processes with respect to dissociation and

  15. 9 CFR 313.5 - Chemical; carbon dioxide.

    Science.gov (United States)

    2010-01-01

    ... the species of animals being anesthetized. They shall be free from pain-producing restraining devices... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Chemical; carbon dioxide. 313.5 Section 313.5 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE...

  16. Gas flaring: Carbon dioxide contribution to global warming ...

    African Journals Online (AJOL)

    Flaring been a source of anthropogenic carbon dioxide, is a concern to skeptics and local oil producing communities as a significant contributor to global warming, environmental degradation, health risk and economic loss. The purpose of the study was to ascertain the impacts of gas flaring on global warming and the local ...

  17. Serpentine dissolution in hydrochloric acid for carbon dioxide sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Amankwah, R.K.; Pickles, C.A. [Queen' s Univ., Kingston, ON (Canada). Dept. of Mining Engineering

    2008-07-01

    Increased carbon dioxide concentrations in the atmosphere can be attributed to industrialization and the associated combustion of large amounts of fossil fuels. The release of carbon dioxide into the atmosphere causes greenhouse gases, which is expected to have a destabilizing effect on the climate. Several methods have been investigated to reduce the amount of greenhouse gases in the atmosphere, such as improved energy efficiency and conservation programs; utilization of alternative energy sources; and carbon dioxide sequestration. This paper discussed the sequestration of carbon dioxide by minerals as a potential method for reducing the greenhouse gas concentration in the atmosphere. The paper presented a study that involved the dissolution of lizardite, a serpentine mineral, in hydrochloric acid at high pressures in an autoclave. The thermodynamics of the system were examined and experimental data were presented. The solubility of the mineral was shown to be strongly dependent on processing time, acid concentration and pulp density but not strongly affected by stirring or temperature. The paper also discussed the characterization of the reacted samples by thermogravimetric analysis, differential scanning calorimetry, and Fourier transform infrared spectroscopy. The reacted samples were compared to the as-received material. It was concluded that the equilibrium calculations, the kinetic experiments and the characterization of the processed samples indicated that a silica-rich layer formed on the lizardite as the magnesium dissolved, and that this layer hindered further dissolution. 13 refs., 1 tab., 8 figs.

  18. Integrated biofuel facility, with carbon dioxide consumption and power generation

    Energy Technology Data Exchange (ETDEWEB)

    Powell, E.E.; Hill, G.A. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Chemical Engineering

    2009-07-01

    This presentation provided details of an economical design for a large-scale integrated biofuel facility for coupled production of bioethanol and biodiesel, with carbon dioxide capture and power generation. Several designs were suggested for both batch and continuous culture operations, taking into account all costs and revenues associated with the complete plant integration. The microalgae species Chlorella vulgaris was cultivated in a novel photobioreactor (PBR) in order to consume industrial carbon dioxide (CO{sub 2}). This photosynthetic culture can also act as a biocathode in a microbial fuel cell (MFC), which when coupled to a typical yeast anodic half cell, results in a complete biological MFC. The photosynthetic MFC produces electricity as well as valuable biomass and by-products. The use of this novel photosynthetic microalgae cathodic half cell in an integrated biofuel facility was discussed. A series of novel PBRs for continuous operation can be integrated into a large-scale bioethanol facility, where the PBRs serve as cathodic half cells and are coupled to the existing yeast fermentation tanks which act as anodic half cells. These coupled MFCs generate electricity for use within the biofuel facility. The microalgae growth provides oil for biodiesel production, in addition to the bioethanol from the yeast fermentation. The photosynthetic cultivation in the cathodic PBR also requires carbon dioxide, resulting in consumption of carbon dioxide from bioethanol production. The paper also discussed the effect of plant design on net present worth and internal rate of return. tabs., figs.

  19. Carbon dioxide uptake by a temperate tidal sea

    NARCIS (Netherlands)

    Klaassen, Wim

    2007-01-01

    Carbon dioxide (CO2) exchange between the atmosphere and the Wadden Sea, a shallow coastal region along the northern Netherlands, has been measured from April 2006 onwards on a tidal flat and over open water. Tidal flat measurements were done using a flux chamber, and ship borne measurements using

  20. Use of carbon dioxide laser in oral soft tissue procedures

    Science.gov (United States)

    Garg, Nimit; Verma, Sunil; Chadha, Minni; Rastogi, Pavitra

    2015-01-01

    Lasers have been introduced in dentistry as an alternative to conventional knife surgery. The advantage to the operator includes a clean dry field that enhances visibility and reduces the procedure time. The patient benefits by minimal postoperative pain and swelling. The paper discusses use of carbon dioxide laser in five conditions commonly encountered in oral cavity. PMID:26668460

  1. A Discovery Experiment: Carbon Dioxide Soap Bubble Dynamics.

    Science.gov (United States)

    Millikan, Roger C.

    1978-01-01

    The observation of soap bubbles in a beaker of carbon dioxide gas helps students to feel the pleasure that comes from understanding nature, from applying that understanding to real problems, and from making unexpected discoveries that yield to analysis. (Author/BB)

  2. Binary mixtures of carbon dioxide and dimethyl ether as alternative ...

    African Journals Online (AJOL)

    Vapor-liquid equilibrium (VLE) data were predicted for the binary mixture of carbon dioxide (CO2) and dimethyl ether (DME) at ten temperatures ranging from 273.15 to 386.56 K and pressure upto 7.9 MPa to observe this mixture's potential of COP enhancement and capacity modulation as a working fluid in a refrigeration ...

  3. Solubilities of sub- and supercritical carbon dioxide in polyester resins

    NARCIS (Netherlands)

    Nalawade, SP; Picchioni, F; Janssen, LPBM; Patil, VE; Keurentjes, JTF; Staudt, R; Nalawade, Sameer P.; Patil, Vishal E.; Keurentjes, Jos T.F.

    In supercritical carbon dioxide (CO2) assisted polymer processes the solubility of CO2 in a polymer plays a vital role. The higher the amount of CO2 dissolved in a polymer the higher is the viscosity reduction of the polymer. Solubilities Of CO2 in polyester resins based on propoxylated bisphenol

  4. Removing carbon dioxide from a stationary source through co ...

    African Journals Online (AJOL)

    Except temperature of solvent, all study variables showed strong relation with the amount of carbon dioxide absorbed (with a P-value < 0.05). Uniquely, this study has evaluated the potential for sodium bicarbonate production from the CO2 absorbed using gravimetric analysis. It is also possible to recover over 28% crystal ...

  5. Kinetics of absorption of carbon dioxide in aqueous ammonia solutions

    NARCIS (Netherlands)

    Derks, P. W. J.; Versteeg, G. F.

    2009-01-01

    In the present work the absorption of carbon dioxide into aqueous ammonia solutions has been studied in a stirred cell reactor, at low temperatures and ammonia concentrations ranging from 0.1 to about 7 kmol m-3. The absorption experiments were carried out at conditions where the so-called pseudo

  6. Heliox Improves Carbon Dioxide Removal during Lung Protective Mechanical Ventilation

    NARCIS (Netherlands)

    Beurskens, Charlotte J; Brevoord, Daniel; Lagrand, Wim K; van den Bergh, Walter M; Vroom, Margreeth B; Preckel, Benedikt; Horn, Janneke; Juffermans, Nicole P

    2014-01-01

    Introduction. Helium is a noble gas with low density and increased carbon dioxide (CO2) diffusion capacity. This allows lower driving pressures in mechanical ventilation and increased CO2 diffusion. We hypothesized that heliox facilitates ventilation in patients during lung-protective mechanical

  7. Intertidal zones as carbon dioxide sources to coastal oceans

    Digital Repository Service at National Institute of Oceanography (India)

    DileepKumar, M.; George, M.D.; Rajagopal, M.D.

    To understand the factors controlling carbon dioxide (CO sub(2)) exchanges near land-sea boundary diurnal observations have been made twice on CO sub(2) in the air and water in a coastal region. The results suggest that CO sub(2) enrichment...

  8. Kenaf seed oil from supercritical carbon dioxide fluid extraction ...

    African Journals Online (AJOL)

    Kenaf seed oil from supercritical carbon dioxide fluid extraction shows cytotoxic effects towards various cancer cell lines. ... African Journal of Biotechnology ... Even though kenaf seed oil from both varieties were cytotoxic to all the cancer cells, kenaf seed oil variety V36 extracted by SFE at 600 bars 40°C (V600/40) was the ...

  9. Trade, production fragmentation, and China's carbon dioxide emissions

    NARCIS (Netherlands)

    Dietzenbacher, Erik; Pei, Jiansuo; Yang, Cuihong

    An input-output framework is adopted to estimate China's carbon dioxide (CO2) emissions as generated by its exports in 2002. More than one half of China's exports are related to international production fragmentation. These processing exports generate relatively little value added but also

  10. Classroom Carbon Dioxide Concentration, School Attendance, and Educational Attainment

    Science.gov (United States)

    Gaihre, Santosh; Semple, Sean; Miller, Janice; Fielding, Shona; Turner, Steve

    2014-01-01

    Background: We tested the hypothesis that classroom carbon dioxide (CO[subscript 2]) concentration is inversely related to child school attendance and educational attainment. Methods: Concentrations of CO[subscript 2] were measured over a 3-5?day period in 60 naturally ventilated classrooms of primary school children in Scotland. Concentrations of…

  11. A new manometric method for measuring carbon dioxide production ...

    African Journals Online (AJOL)

    This paper describe a technique for carbon dioxide (CO2) measurement based on the displacement of acidifying liquid in burette at constant pressure. It was adapted to allow the growth of ... The CO2 production rate was higher with the parental strain (6.5 mM/ h) than with the variants. The amount of CO2 produced was ...

  12. TWO-PHASE EJECTOR of CARBON DIOXIDE HEAT PUMP CALCULUS

    Directory of Open Access Journals (Sweden)

    Sit B.M.

    2010-12-01

    Full Text Available It is presented the calculus of the two-phase ejector for carbon dioxide heat pump. The method of calculus is based on the method elaborated by S.M. Kandil, W.E. Lear, S.A. Sherif, and is modified taking into account entrainment ratio as the input for the calculus.

  13. Metathesis of carbon dioxide and phenyl isocyanate catalysed by ...

    Indian Academy of Sciences (India)

    The insertion reactions of zirconium(IV) -butoxide and titanium(IV) -butoxide with a heterocumulene like carbodiimide, carbon dioxide or phenyl isocyanate are compared. Both give an intermediate which carries out metathesis at elevated temperatures by inserting a second heterocumulene in a head-to-head fashion.

  14. Characterization of potassium glycinate for carbon dioxide absorption purposes

    NARCIS (Netherlands)

    Portugal, A. F.; Derks, P. W. J.; Versteeg, G. F.; Magalhaes, F. D.; Mendes, A.

    2007-01-01

    Aqueous solutions of potassium glycinate were characterized for carbon dioxide absorption purposes. Density and viscosity of these solutions, with concentrations ranging from 0.1 to 3 M, were determined at temperatures from 293 to 313 K. Diffusivity of CO2 in solution was estimated applying the

  15. Solubility of carbon dioxide in aqueous piperazine solutions

    NARCIS (Netherlands)

    Derks, P. W. J.; Dijkstra, H. B. S.; Hogendoorn, J. A.; Versteeg, G. F.

    2005-01-01

    In the present work, new experimental data are presented on the solubility of carbon dioxide in aqueous piperazine solutions, for concentrations of 0.2 and 0.6 molar piperazine and temperatures of 25, 40, and 70°C respectively. The present data, and other data available in the literature, were

  16. Intravenous carbon dioxide as an echocardiographic contrast agent

    NARCIS (Netherlands)

    R.S. Meltzer (Richard); P.W.J.C. Serruys (Patrick); P.G. Hugenholtz (Paul); J.R.T.C. Roelandt (Jos)

    1981-01-01

    textabstractIntravenous carbon dioxide (CO2) was employed to cause echocardiographic contrast in 40 patients. One to 3 cc of medically pure CO2 were agitated with 5 to 8 cc of 5% dextrose in water and rapidly injected into an upper extremity vein. Contrast was obtained in all patients. In 33

  17. Carbon dioxide inhibition of yeast growth in biomass production.

    Science.gov (United States)

    Chen, S L; Gutmains, F

    1976-10-01

    Saccharomyces cerevisiae was grown under aerobic and substrate-limiting conditions for efficient biomass production. Under these conditions, where the sugar substrate was fed incrementally, the growth pattern of the yeast cells was found to be uniform, as indicated by a constant respiratory quotient during the entire growing period. The effect of carbon dioxide was investigated by replacing portions of the nitrogen in the air stream with carbon dioxide, while maintaining the oxygen content at the normal 20% level, so that identical oxygen transfer rate and atmospheric pressure were maintained for all experiments with different partial pressures of carbon dioxide. Inhibition of yeast growth was negligible below 20% CO2 in the aeration mixture. Slight inhibition was noted at the 40% CO2 level and significant inhibition was noted above the 50% CO2 level, corresponding to 1.6 X 10(-2)M of dissolved CO2 in the fermentor broth. High carbon dioxide content in the gas phase also inhibited the fermentation activity of baker's yeast.

  18. Transferable force field for carbon dioxide adsorption in zeolites

    NARCIS (Netherlands)

    García-Sánchez, A.; Ania, C.O.; Parra, J.B.; Dubbeldam, D.; Vlugt, T.J.H.; Krishna, R.; Calero, S.

    2009-01-01

    We have developed a complete force field that accurately reproduces the adsorption properties of carbon dioxide in a variety of zeolites with different topologies and compositions. The force field parameters were obtained by fitting to our own experimental data and validated with available data

  19. Monthly, global emissions of carbon dioxide from fossil fuel consumption

    DEFF Research Database (Denmark)

    Andres, R.J.; Gregg, Jay Sterling; Losey, L.

    2011-01-01

    This paper examines available data, develops a strategy and presents a monthly, global time series of fossil-fuel carbon dioxide emissions for the years 1950–2006. This monthly time series was constructed from detailed study of monthly data from the 21 countries that account for approximately 80...

  20. The chemical fixation of carbon dioxide by tetramethylguanidine and ...

    African Journals Online (AJOL)

    ... with TMG and TBD at normal conditions of temperature and pressure. Finally it was also proposed that, the method used could be useful for the uptake and release of atmospheric CO2. Keywords: Carbon dioxide, Chemical fixation, Heteronuclear Multiple-Bond Correlation Tetramethylguanidine, Triazabicyclo decene ...

  1. Open nanoporous morphologies from polymeric blends by carbon dioxide foaming

    NARCIS (Netherlands)

    Krause, B.; Diekmann, K.; van der Vegt, N.F.A.; Wessling, Matthias

    2002-01-01

    We report the formation of open nanoporous polymer films composed of homogeneous polysulfone/polyimide blends. Porosity is introduced by expansion of carbon dioxide-saturated films at elevated temperatures. To interpret details of the porous morphologies in terms of the experimental conditions

  2. Supercritical carbon dioxide extraction of oil from Clanis bilineata ...

    African Journals Online (AJOL)

    Oil was extracted from the dry meat of Clanis bilineata (Lepidoptera) using supercritical carbon dioxide in a continuous flow extractor. The following optimum extraction conditions were investigated: temperature, 35°C; pressure, 25 MPa; supercritical CO2 flow rate, 20 L/min and time, 60 min. Under these extraction ...

  3. Dynamics of Carbon-dioxide production and its economic importance

    African Journals Online (AJOL)

    Dynamics of Carbon-dioxide production and its economic importance. I A Musa. Abstract. No Abstract. GJPAS Vol. 13 (4) 2007: pp.517-521. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Article Metrics. No metrics found. Metrics powered by PLOS ALM

  4. Dry-cleaning with high-pressure carbon dioxide

    NARCIS (Netherlands)

    Van Roosmalen, M.J.E.

    2003-01-01

    Dry-cleaning is a process for removing soils and stains from fabrics and garments which uses a non-aqueous solvent with detergent added. The currently most used dry-cleaning solvent is perchloroethylene (PER), which is toxic, environmentally harmful and suspected to be carcinogenic. Carbon dioxide

  5. Carbon dioxide and nisin act synergistically on Listeria monocytogenes

    DEFF Research Database (Denmark)

    Nilsson, Lilian; Chen, Y.H.; Chikindas, M.L.

    2000-01-01

    for cultures in CO2. This synergism between nisin and CO2 was examined mechanistically by following the leakage of carboxyfluorescein (CF) from listerial liposomes. Carbon dioxide enhanced nisin-induced CF leakage, indicating that the synergistic action of CO2 and nisin occurs at the cytoplasmic membrane...

  6. Measurements and interpretation of oxygen isotopes in stratospheric carbon dioxide

    NARCIS (Netherlands)

    Mrozek, D.J.

    2017-01-01

    Carbon dioxide (CO2) is an important natural and anthropogenic greenhouse gas in Earth's atmosphere. Its atmospheric mole fraction has increased from about 280 ppm (parts per million) in the pre-industrial atmosphere to more than 400 ppm at present. Investigation of the stable isotopic composition

  7. Supercritical carbon dioxide cycle control analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Moisseytsev, A.; Sienicki, J. J. (Nuclear Engineering Division)

    2011-04-11

    This report documents work carried out during FY 2008 on further investigation of control strategies for supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle energy converters. The main focus of the present work has been on investigation of the S-CO{sub 2} cycle control and behavior under conditions not covered by previous work. An important scenario which has not been previously calculated involves cycle operation for a Sodium-Cooled Fast Reactor (SFR) following a reactor scram event and the transition to the primary coolant natural circulation and decay heat removal. The Argonne National Laboratory (ANL) Plant Dynamics Code has been applied to investigate the dynamic behavior of the 96 MWe (250 MWt) Advanced Burner Test Reactor (ABTR) S-CO{sub 2} Brayton cycle following scram. The timescale for the primary sodium flowrate to coast down and the transition to natural circulation to occur was calculated with the SAS4A/SASSYS-1 computer code and found to be about 400 seconds. It is assumed that after this time, decay heat is removed by the normal ABTR shutdown heat removal system incorporating a dedicated shutdown heat removal S-CO{sub 2} pump and cooler. The ANL Plant Dynamics Code configured for the Small Secure Transportable Autonomous Reactor (SSTAR) Lead-Cooled Fast Reactor (LFR) was utilized to model the S-CO{sub 2} Brayton cycle with a decaying liquid metal coolant flow to the Pb-to-CO{sub 2} heat exchangers and temperatures reflecting the decaying core power and heat removal by the cycle. The results obtained in this manner are approximate but indicative of the cycle transient performance. The ANL Plant Dynamics Code calculations show that the S-CO{sub 2} cycle can operate for about 400 seconds following the reactor scram driven by the thermal energy stored in the reactor structures and coolant such that heat removal from the reactor exceeds the decay heat generation. Based on the results, requirements for the shutdown heat removal system may be defined

  8. Photosynthesis in Rhodospirillum rubrum. II. Photoheterotrophic carbon dioxide fixation.

    Science.gov (United States)

    Anderson, L; Fuller, R C

    1967-04-01

    The contribution of the reductive pentose phosphate cycle to the photometabolism of carbon dioxide and to carbon metabolism in Rhodospirillum rubrum grown photoheterotrophically with l-malate as the carbon source is nil, unlike autotrophically grown R. rubrum. Glycolic acid appears to be the first stable product of CO(2) fixation in R. rubrum cultured photoheterotrophically on l-malate. The results obtained in (14)CO(2) fixation experiments suggest that the photometabolism of CO(2) through glycolate into malate is a major pathway of CO(2) fixation in such cells. However, l-malate was a much more efficient precursor of phosphate esters, and of glutamic acid, than was carbon dioxide; l-malate is therefore, in this case, a far more important source of cell carbon than is carbon dioxide. The products of the light-dependent incorporation of CO(2) and of acetate were investigated in R. rubrum grown photoheterotrophically on acetate. Carboxylation reactions and the reductive pentose phosphate cycle are apparently of greater significance in the photometabolism of acetate heterotrophs than in malate heterotrophs; the photometabolism of the acetate photoheterotrophs seems to be intermediate between the photoheterotrophy of malate heterotrophs and strict autotrophy.

  9. Photosynthesis in Rhodospirillum rubrum. II. Photoheterotrophic Carbon Dioxide Fixation 1

    Science.gov (United States)

    Anderson, Louise; Fuller, R. C.

    1967-01-01

    The contribution of the reductive pentose phosphate cycle to the photometabolism of carbon dioxide and to carbon metabolism in Rhodospirillum rubrum grown photoheterotrophically with l-malate as the carbon source is nil, unlike autotrophically grown R. rubrum. Glycolic acid appears to be the first stable product of CO2 fixation in R. rubrum cultured photoheterotrophically on l-malate. The results obtained in 14CO2 fixation experiments suggest that the photometabolism of CO2 through glycolate into malate is a major pathway of CO2 fixation in such cells. However, l-malate was a much more efficient precursor of phosphate esters, and of glutamic acid, than was carbon dioxide; l-malate is therefore, in this case, a far more important source of cell carbon than is carbon dioxide. The products of the light-dependent incorporation of CO2 and of acetate were investigated in R. rubrum grown photoheterotrophically on acetate. Carboxylation reactions and the reductive pentose phosphate cycle are apparently of greater significance in the photometabolism of acetate heterotrophs than in malate heterotrophs; the photometabolism of the acetate photoheterotrophs seems to be intermediate between the photoheterotrophy of malate heterotrophs and strict autotrophy. PMID:6042358

  10. The impact of carbon dioxide in stored-product insect treatment with ...

    African Journals Online (AJOL)

    In laboratory experiments, toxicity of carbon dioxide and carbon dioxide - phosphine mixture was investigated against 4 species of stored-product insects. In empty-space trials, estimates of the median lethal doses of carbon dioxide against adults of Oryzaephilus surinamensis (L.), Lasioderma serricorne (F.) and eggs of ...

  11. Microporous metal-organic framework with potential for carbon dioxide capture at ambient conditions

    NARCIS (Netherlands)

    Xiang, S.C.; He, Y.; Zhang, Z.; Wu, H.; Zhou, W.; Krishna, R.; Chen, B.

    2012-01-01

    Carbon dioxide capture and separation are important industrial processes that allow the use of carbon dioxide for the production of a range of chemical products and materials, and to minimize the effects of carbon dioxide emission. Porous metal-organic frameworks are promising materials to achieve

  12. Carbon dioxide euthanasia in rats: Oxygen supplementation minimizes signs of agitation and asphyxia

    NARCIS (Netherlands)

    Coenen, A.M.L.; Drinkenburg, W.H.I.M.; Hoenderken, R.; Luijtelaar, E.L.J.M. van

    1995-01-01

    This paper records the effects of carbon dioxide when used for euthanasia, on behaviour, electrical brain activity and heart rate in rats. Four different methods were used. Animals were placed in a box (a) that was completely filled with carbon dioxide; (b) into which carbon dioxide was streamed at

  13. 27 CFR 27.42a - Still wines containing carbon dioxide.

    Science.gov (United States)

    2010-04-01

    ... carbon dioxide. 27.42a Section 27.42a Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... On Imported Distilled Spirits, Wines, and Beer Wines § 27.42a Still wines containing carbon dioxide. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine; except...

  14. Carbon Dioxide Leaser For The Treatment Of Keloids

    Directory of Open Access Journals (Sweden)

    Verma Kaushal K

    2002-01-01

    Full Text Available Keloids are difficult to treat medically or surgically. Carbon dioxide (CO2 laser is considered to be a better therapeutic option due to less chances of recurrence with this modality. Fourteen patients, 4 males and 10 females, between 9 and 36 years of age having keloids for 1 to 10 years were included in this study. The lesions were present on chest, ear lobes, nape of neck, forearm, arm and shoulder. CO2 laser with a power setting of 10 to 20 watts was used in continuous mode to vaporize/excise the lesions. The patients were followed up at the end of last week, 2nd week and then every 4 weeks for 3 months to evaluate the response to treatment. Twelve patients followed up regularly and completed this study. Six patients with keliods on chest had 50 to 70% response. Remaining 6 patients with keliods on chest had 50 to 70% response. Remaining 6 patients with lesions on the ear lobes (3, showed 50 to 90% response. Nape of neck (1, shoulder, arm and forearm (2 lesions had 50 to 90% response. In all, except one patient the healing started by 4 weeks and complete healing of the treatment area occurred within 8 weeks. Four patients with poor response to CO2 laser alone were given in addition intralesional triaminolone acetonide 40mg/ml, which resulted in a better response in these patients. One patient had depigmentation of the treated area. There were no side effects in other patients. We therefore conclude that CO2 laser is a good therapeutic modality for the treatment of keloids: however recurrence on long term follow up needs to be observed.

  15. Methane and Carbon Dioxide Emissions from Different Composting Periods

    Directory of Open Access Journals (Sweden)

    Cheng-Hsiung Chang

    2009-01-01

    Full Text Available To investigate green house gas emissions from compost preparations, methane and carbon dioxide concentrations and emission rates at different accumulative times and composting periods were determined. While the accumulative time was less than 10 min with a closed acrylic chamber, meth ane and carbon dioxide emissions in creased slightly but with high fluntuation in the sampling e ror, and these values decreased significantly when the accumulative time was more than 20 min. During the 8 weeks of composting, the methane emission rate reaches its peak near the end of the second week and the carbon dioxide emission rate does the same near the end of third week. Meth ane and carbon dioxide emissions had high val ues at the first stage of com post ing and then de creased grad u ally for the ma tu rity of com post. Carbon dioxide emission (y was significantly related to temperature (x1, moisture content (x2, and total or ganiccarbon (x3; and there gression equation is: y = 3.11907x1 + 6.19236x2 - 6.63081x3 - 50.62498. The re gres sion equa tion be tween meth ane emis sion (y? and mois ture con tent (x2, pH (x4, C/N ra tio (x5, and ash con tent (x6 is: y?= 0.13225x2 - 0.97046x4 - 1.10599x5 - 0.55220x6 + 50.77057 in the ini tial com post ing stage (weeks 1 to 3; while, the equa tion is: y?= 0.02824x2 - 0.0037x4 - 0.1499x5 - 0.07013x6 + 4.13589 in the later compost ing stage (weeks 4 to 8. Dif ferent stage composts have significant variation of properties and greenhouse gas emissions. Moreover, the emissions may be reduced by manipulating the proper factors.

  16. Can Earthworm "mix up" Soil Carbon Budgets in Temperate Forests Under Elevated Carbon Dioxide?

    Science.gov (United States)

    Sánchez-de León, Y.; González-Meler, M.; Sturchio, N. C.; Wise, D. H.; Norby, R. J.

    2008-12-01

    The effects of global change on earthworms and their associated feedbacks on soil and ecosystem processes have been largely overlooked. We studied how the responses of a temperate deciduous forest to elevated carbon dioxide atmospheric concentrations (e[CO2]) influence earthworms and the soil processes affected by them. Our objectives were to: i) identify soil layers of active soil mixing under e[CO2] and current carbon dioxide atmospheric concentrations (c[CO2]) using fallout cesium (137Cs), ii) study how e[CO2] affects earthworm populations, iii) understand the relationship between soil mixing and earthworms at our study site, and iv) identify the implications of earthworm-mediated soil mixing for the carbon budget of a temperate forest. To study soil mixing, we measured vertical 137Cs activity in soil cores (0-24 cm depth) collected in replicated e[CO2] and c[CO2] sweetgum (Liquidambar styraciflua) plots (n = 2) in a Free Air CO2 Enrichment (FACE) ecosystem experiment at Oak Ridge National Laboratory. We measured earthworm density and fresh weight in the plots in areas adjacent to where soil cores were taken. Preliminary results on the vertical distribution of 137Cs in the c[CO2] treatments showed that higher 137Cs activity was located from 8-16 cm depth and no 137Cs activity was measured below 20 cm. In contrast, in the e[CO2] treatment, peak 137Cs activity was slightly deeper (10-18 cm), and 137Cs activity was still measured below 22 cm. Mean earthworm density was higher in e[CO2] than c[CO2] treatments (168 m-2 and 87 m-2, respectively; p = 0.046); earthworm fresh weights, however, did not differ significantly between treatments (32 g m-2 and 18 g m-2, respectively; p = 0.182). The 137Cs vertical distribution suggest that soil mixing occurs deeper in e[CO2] than in c[CO2] treatments, which is consistent with higher earthworm densities in e[CO2] than in c[CO2] treatments. Mixing deeper low carbon content soil with shallower high carbon soil may result in a

  17. Synthesis of Chiral Cyclic Carbonates via Kinetic Resolution of Racemic Epoxides and Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Xiao Wu

    2016-01-01

    Full Text Available The catalytic synthesis of cyclic carbonates using carbon dioxide as a C1-building block is a highly active area of research. Here, we review the catalytic production of enantiomerically enriched cyclic carbonates via kinetic resolution of racemic epoxides catalysed by metal-containing catalyst systems.

  18. Kinetics of absorption of carbon dioxide in aqueous MDEA solutions with carbonic anhydrase at 298 K

    NARCIS (Netherlands)

    Penders-van Elk, Nathalie J. M. C.; Derks, Peter W. J.; Fradette, Sylvie; Versteeg, Geert F.

    In present work the absorption of carbon dioxide in aqueous N-methyldiethanolamine (MDEA) solutions with and without the enzyme carbonic anhydrase has been studied in a stirred cell at 298 K, with MDEA concentrations ranging from 0.5 to 4 kmol m(-3) and carbonic anhydrase concentrations ranging from

  19. Mineralization of Carbon Dioxide: Literature Review

    Energy Technology Data Exchange (ETDEWEB)

    Romanov, V; Soong, Y; Carney, C; Rush, G; Nielsen, B; O' Connor, W

    2015-01-01

    CCS research has been focused on CO2 storage in geologic formations, with many potential risks. An alternative to conventional geologic storage is carbon mineralization, where CO2 is reacted with metal cations to form carbonate minerals. Mineralization methods can be broadly divided into two categories: in situ and ex situ. In situ mineralization, or mineral trapping, is a component of underground geologic sequestration, in which a portion of the injected CO2 reacts with alkaline rock present in the target formation to form solid carbonate species. In ex situ mineralization, the carbonation reaction occurs above ground, within a separate reactor or industrial process. This literature review is meant to provide an update on the current status of research on CO2 mineralization. 2

  20. Carbon dioxide: A new material for energy storage

    Directory of Open Access Journals (Sweden)

    Jacques Amouroux

    2014-08-01

    Full Text Available Though carbon dioxide is the main green house gas due to burning of fossil resource or miscellaneous chemical processes, we propose here that carbon dioxide be a new material for energy storage. Since it can be the key to find the solution for three critical issues facing the world: food ecosystems, the greenhouse issue and energy storage. We propose to identify the carbon recovery through a circular industrial revolution in the first part, and in the second part we present the starting way of three business plants to do that from industrial examples. By pointing out all the economic constraints and the hidden competitions between energy, water and food, we try to qualify the phrase “sustainable development” and open the way of a huge circular economy.

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

    Science.gov (United States)

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

    1981-01-01

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

  2. Atmospheric carbon dioxide levels over phanerozoic time.

    Science.gov (United States)

    Berner, R A

    1990-09-21

    A new model has been constructed for calculating the level of atmospheric CO(2) during the past 570 million years. A series of successive steady states for CO(2) is used in order to calculate CO(2) level from a feedback function for the weathering of silicate minerals. Processes considered are: sedimentary burial of organic matter and carbonates; continental weathering of silicates, carbonates, and organic matter; and volcanic and metamorphic degassing of CO(2). Sediment burial rates are calculated with the use of an isotope mass-balance model and carbon isotopic data on ancient seawater. Weathering rates are calculated from estimates of past changes in continental land area, mean elevation, and river runoff combined with estimates of the effects of the evolution of vascular land plants. Past degassing rates are estimated from changes in the rate of generation of sea floor and the shift of carbonate deposition from platforms to the deep sea. The model results indicate that CO(2) levels were high during the Mesozoic and early Paleozoic and low during the Permo-Carboniferous and late Cenozoic. These results correspond to independently deduced Phanerozoic paleoclimates and support the notion that the atmospheric CO(2) greenhouse mechanism is a major control on climate over very long time scales.

  3. Weathering approaches to carbon dioxide sequestration

    NARCIS (Netherlands)

    Schuiling, R.D.

    2012-01-01

    The aim of enhanced weathering is to capture CO2 by the carbonation of silicates, or by dissolution of these silicates during which the greenhouse gas CO2 is converted to bicarbonate in solution. Research in this field is still focused on increasing the rate of reaction, but the required

  4. Carbon dioxide adsorption in graphene sheets

    Science.gov (United States)

    Mishra, Ashish Kumar; Ramaprabhu, Sundara

    2011-09-01

    Control over the CO2 emission via automobiles and industrial exhaust in atmosphere, is one of the major concerns to render environmental friendly milieu. Adsorption can be considered to be one of the more promising methods, offering potential energy savings compared to absorbent systems. Different carbon nanostructures (activated carbon and carbon nanotubes) have attracted attention as CO2 adsorbents due to their unique surface morphology. In the present work, we have demonstrated the CO2 adsorption capacity of graphene, prepared via hydrogen induced exfoliation of graphitic oxide at moderate temperatures. The CO2 adsorption study was performed using high pressure Sieverts apparatus and capacity was calculated by gas equation using van der Waals corrections. Physical adsorption of CO2 molecules in graphene was confirmed by FTIR study. Synthesis of graphene sheets via hydrogen exfoliation is possible at large scale and lower cost and higher adsorption capacity of as prepared graphene compared to other carbon nanostructures suggests its possible use as CO2 adsorbent for industrial application. Maximum adsorption capacity of 21.6 mmole/g was observed at 11 bar pressure and room temperature (25 °C).

  5. Carbon dioxide adsorption in graphene sheets

    Directory of Open Access Journals (Sweden)

    Ashish Kumar Mishra

    2011-09-01

    Full Text Available Control over the CO2 emission via automobiles and industrial exhaust in atmosphere, is one of the major concerns to render environmental friendly milieu. Adsorption can be considered to be one of the more promising methods, offering potential energy savings compared to absorbent systems. Different carbon nanostructures (activated carbon and carbon nanotubes have attracted attention as CO2 adsorbents due to their unique surface morphology. In the present work, we have demonstrated the CO2 adsorption capacity of graphene, prepared via hydrogen induced exfoliation of graphitic oxide at moderate temperatures. The CO2 adsorption study was performed using high pressure Sieverts apparatus and capacity was calculated by gas equation using van der Waals corrections. Physical adsorption of CO2 molecules in graphene was confirmed by FTIR study. Synthesis of graphene sheets via hydrogen exfoliation is possible at large scale and lower cost and higher adsorption capacity of as prepared graphene compared to other carbon nanostructures suggests its possible use as CO2 adsorbent for industrial application. Maximum adsorption capacity of 21.6 mmole/g was observed at 11 bar pressure and room temperature (25 ºC.

  6. Measuring of carbon dioxide in water/steam cycle

    Energy Technology Data Exchange (ETDEWEB)

    Daucik, Karol

    2004-12-01

    Prevention of corrosion of the water/steam cycle caused by anionic contamination is based on control of acid conductivity. The contribution of carbon dioxide to the corrosion is very limited and yet it contributes considerably to the acid conductivity as one of the most common contaminants. Monitoring of the dangerous anionic contamination has therefore been on the agenda for many years. Commercial monitors for this purpose are based on separation of carbon dioxide from stronger acids due to its high volatility. A systematic error in these monitors comes from high volatility of other anionic contaminants, e.g. formic and acetic acid. The aim of this investigation was to show that the separation could be made on a weak base anion exchanger working on the basis of differences in the strength of acids. This simple method was expected to give reliable results with low investment and low operating costs. The results showed that the separation is indeed effective. However, reliable data are received only if the anion exchange resin is in equilibrium with the actual concentration of carbon dioxide in the sample. It may take several hours to reach this equilibrium by natural flow of the sample through the anion exchange column. Changes in the concentration of carbon dioxide in the sample will therefore temporarily give false results until a new equilibrium is achieved. The simple monitoring method can be used only in places, where verification of carbon dioxide contamination is required by long-term operation with elevated and stable acid conductivity in the steam. For future design it is suggested to install a forced achievement of the new equilibrium by conditioning of the resin by means of short-lived additions of carbon dioxide or sodium hydroxide to the sample. In these periods the output from the monitor will be suspended. Output close to the equilibrium is expected to be reached within 10 minutes. This new suggested procedure will complicate the monitoring to such a

  7. CARBON DIOXIDE MITIGATION THROUGH CONTROLLED PHOTOSYNTHESIS

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2000-10-01

    This research was undertaken to meet the need for a robust portfolio of carbon management options to ensure continued use of coal in electrical power generation. In response to this need, the Ohio Coal Research Center at Ohio University developed a novel technique to control the emissions of CO{sub 2} from fossil-fired power plants by growing organisms capable of converting CO{sub 2} to complex sugars through the process of photosynthesis. Once harvested, the organisms could be used in the production of fertilizer, as a biomass fuel, or fermented to produce alcohols. In this work, a mesophilic organism, Nostoc 86-3, was examined with respect to the use of thermophilic algae to recycle CO{sub 2} from scrubbed stack gases. The organisms were grown on stationary surfaces to facilitate algal stability and promote light distribution. The testing done throughout the year examined properties of CO{sub 2} concentration, temperature, light intensity, and light duration on process viability and the growth of the Nostoc. The results indicate that the Nostoc species is suitable only in a temperature range below 125 F, which may be practical given flue gas cooling. Further, results indicate that high lighting levels are not suitable for this organism, as bleaching occurs and growth rates are inhibited. Similarly, the organisms do not respond well to extended lighting durations, requiring a significant (greater than eight hour) dark cycle on a consistent basis. Other results indicate a relative insensitivity to CO{sub 2} levels between 7-12% and CO levels as high as 800 ppm. Other significant results alluded to previously, relate to the development of the overall process. Two processes developed during the year offer tremendous potential to enhance process viability. First, integration of solar collection and distribution technology from Oak Ridge laboratories could provide a significant space savings and enhanced use of solar energy. Second, the use of translating slug flow

  8. Supply of carbon dioxide for enhanced oil recovery. Final report, October 15, 1976--September 1, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Rump, W.M.; Hare, M.; Porter, R.E.

    1977-09-01

    Results are presented from a study of the carbon dioxide supply situation for miscible flooding operations to enhance oil recovery. Candidate oil reservoirs were identified, and the carbon dioxide requirements and the potential recoverable oil for some of these were estimated. A survey of carbon dioxide sources has been conducted within the geographic areas where candidate oil reservoirs exist. Sources considered were both high and low quality gases from combustion vents, chemical process stacks, and naturally occurring gas deposits. The survey shows more than enough carbon dioxide is available from above-ground sources alone to meet expected demands. Systems to purify and deliver the carbon dioxide were designed and the costs of the delivered carbon dioxide estimated. Lowest cost is carbon dioxide from natural source with credit for by-product methane. A more comprehensive survey of above-ground and natural sources is recommended.

  9. Carbonic acid as a reserve of carbon dioxide on icy moons: The formation of carbon dioxide (CO{sub 2}) in a polar environment

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Brant M.; Kaiser, Ralf I. [W. M. Keck Research Laboratory in Astrochemistry, University of Hawai' i at Manoa, Honolulu, HI 96822 (United States); Strazzulla, Giovanni, E-mail: brantmj@hawaii.edu [INAF-Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95123 Catania (Italy)

    2014-06-20

    Carbon dioxide (CO{sub 2}) has been detected on the surface of several icy moons of Jupiter and Saturn via observation of the ν{sub 3} band with the Near-Infrared Mapping Spectrometer on board the Galileo spacecraft and the Visible-Infrared Mapping Spectrometer on board the Cassini spacecraft. Interestingly, the CO{sub 2} band for several of these moons exhibits a blueshift along with a broader profile than that seen in laboratory studies and other astrophysical environments. As such, numerous attempts have been made in order to clarify this abnormal behavior; however, it currently lacks an acceptable physical or chemical explanation. We present a rather surprising result pertaining to the synthesis of carbon dioxide in a polar environment. Here, carbonic acid was synthesized in a water (H{sub 2}O)-carbon dioxide (CO{sub 2}) (1:5) ice mixture exposed to ionizing radiation in the form of 5 keV electrons. The irradiated ice mixture was then annealed, producing pure carbonic acid which was then subsequently irradiated, recycling water and carbon dioxide. However, the observed carbon dioxide ν{sub 3} band matches almost exactly with that observed on Callisto; subsequent temperature program desorption studies reveal that carbon dioxide synthesized under these conditions remains in solid form until 160 K, i.e., the sublimation temperature of water. Consequently, our results suggest that carbon dioxide on Callisto as well as other icy moons is indeed complexed with water rationalizing the shift in peak frequency, broad profile, and the solid state existence on these relatively warm moons.

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

    Science.gov (United States)

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

    2015-01-01

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

  11. Production of lightweight aggregate from industrial waste and carbon dioxide.

    Science.gov (United States)

    Gunning, Peter J; Hills, Colin D; Carey, Paula J

    2009-10-01

    The concomitant recycling of waste and carbon dioxide emissions is the subject of developing technology designed to close the industrial process loop and facilitate the bulk-re-use of waste in, for example, construction. The present work discusses a treatment step that employs accelerated carbonation to convert gaseous carbon dioxide into solid calcium carbonate through a reaction with industrial thermal residues. Treatment by accelerated carbonation enabled a synthetic aggregate to be made from thermal residues and waste quarry fines. The aggregates produced had a bulk density below 1000 kg/m(3) and a high water absorption capacity. Aggregate crushing strengths were between 30% and 90% stronger than the proprietary lightweight expanded clay aggregate available in the UK. Cast concrete blocks containing the carbonated aggregate achieve compressive strengths of 24 MPa, making them suitable for use with concrete exposed to non-aggressive service environments. The energy intensive firing and sintering processes traditionally required to produce lightweight aggregates can now be augmented by a cold-bonding, low energy method that contributes to the reduction of green house gases to the atmosphere.

  12. Carbon Dioxide Snow Storms During the Polar Night on Mars

    Science.gov (United States)

    Toon, Owen B.; Colaprete, Anthony

    2001-01-01

    The Mars Orbiter Laser Altimeter (MOLA) detected clouds associated with topographic features during the polar night on Mars. While uplift generated from flow over mountains initiates clouds on both Earth and Mars, we suggest that the Martian clouds differ greatly from terrestrial mountain wave clouds. Terrestrial wave clouds are generally compact features with sharp edges due to the relatively small particles in them. However, we find that the large mass of condensible carbon dioxide on Mars leads to clouds with snow tails that may extend many kilometers down wind from the mountain and even reach the surface. Both the observations and the simulations suggest substantial carbon dioxide snow precipitation in association with the underlying topography. This precipitation deposits CO2, dust and water ice to the polar caps, and may lead to propagating geologic features in the Martian polar regions.

  13. Regenerable immobilized aminosilane sorbents for carbon dioxide capture applications

    Science.gov (United States)

    Gay, McMahan; Choi, Sunho; Jones, Christopher W

    2014-09-16

    A method for the separation of carbon dioxide from ambient air and flue gases is provided wherein a phase separating moiety with a second moiety are simultaneously coupled and bonded onto an inert substrate to create a mixture which is subsequently contacted with flue gases or ambient air. The phase-separating moiety is an amine whereas the second moiety is an aminosilane, or a Group 4 propoxide such as titanium (IV) propoxide (tetrapropyl orthotitanate, C.sub.12H.sub.28O.sub.4Ti). The second moiety makes the phase-separating moiety insoluble in the pores of the inert substrate. The new sorbents have a high carbon dioxide loading capacity and considerable stability over hundreds of cycles. The synthesis method is readily scalable for commercial and industrial production.

  14. Hydrogen Storage in the Carbon Dioxide - Formic Acid Cycle.

    Science.gov (United States)

    Fink, Cornel; Montandon-Clerc, Mickael; Laurenczy, Gabor

    2015-01-01

    This year Mankind will release about 39 Gt carbon dioxide into the earth's atmosphere, where it acts as a greenhouse gas. The chemical transformation of carbon dioxide into useful products becomes increasingly important, as the CO(2) concentration in the atmosphere has reached 400 ppm. One approach to contribute to the decrease of this hazardous emission is to recycle CO(2), for example reducing it to formic acid. The hydrogenation of CO(2) can be achieved with a series of catalysts under basic and acidic conditions, in wide variety of solvents. To realize a hydrogen-based charge-discharge device ('hydrogen battery'), one also needs efficient catalysts for the reverse reaction, the dehydrogenation of formic acid. Despite of the fact that the overwhelming majority of these reactions are carried out using precious metals-based catalysts (mainly Ru), we review here developments for catalytic hydrogen evolution from formic acid with iron-based complexes.

  15. Current views on the regulation of autotrophic carbon dioxide fixation via the Calvin cycle in bacteria

    NARCIS (Netherlands)

    Dijkhuizen, L.; Harder, W.

    1984-01-01

    The Calvin cycle of carbon dioxide fixation constitutes a biosynthetic pathway for the generation of (multi-carbon) intermediates of central metabolism from the one-carbon compound carbon dioxide. The product of this cycle can be used as a precursor for the synthesis of all components of cell

  16. Modeling Carbon Dioxide Storage in the Basal Aquifer of Canada

    Science.gov (United States)

    Huang, X.; Bandilla, K.; Celia, M. A.; Bachu, S.; Rebscher, D.; Zhou, Q.; Birkholzer, J. T.

    2012-12-01

    Reducing anthropogenic carbon dioxide (CO2) emissions into the atmosphere is a key challenge for society. Geological CO2 storage in deep saline aquifers is one of the most promising solutions to decrease carbon emissions. One such deep saline aquifer targeted for industrial-scale CO2 injection is the Basal Aquifer of Prairie Region in Canada and Northern Plains in the US. The aquifer stretches across three provinces (Alberta, Saskatchewan and Manitoba) and three states (Montana, North and South Dakota), and covers approximately 1,320,000 km2 (Figure 1). A large number of stationary CO2 sources lie within the foot print of the aquifer, and several CO2 injection projects are in the planning stage. In order for CO2 sequestration to be successful, the injected CO2 needs to stay isolated from the atmosphere for many centuries. Mathematical models are useful tools to assess the fate of both the injected CO2 and the resident brine. These models vary in complexity from fully three-dimensional multi-phase numerical reservoir simulators to simple semi-analytical solutions. In this presentation we compare a cascade of models ranging from single-phase semi-analytic solutions to multi-phase numerical simulators to determine the ability of each of these approaches to predict the pressure response in the injection formation. The majority of the models in this study are based on vertically-integrated governing equations; such models are computationally efficient, allow for reduced data input, and are broadly consistent with the flow physics. The petro-physical parameters and geometries used in this study are based on the geology of the Canadian section of the Basal Aquifer. Approximately ten injection sites are included in the model, with locations and injection rates based on planned injection operations. The predicted areas of review of the injection operations are used as a comparison metric among the different simulation approaches. Areal extent of the Basal Aquifer (*Source

  17. Using LMDI approach to analyze changes in carbon dioxide emissions of China’s logistics industry

    Directory of Open Access Journals (Sweden)

    Ying Dai

    2015-05-01

    Full Text Available Purpose: China is confronting with tremendous pressure in carbon emission reduction. While logistics industry seriously relies on fossil fuel, and emits greenhouse gas, especially carbon dioxide. The aim of this article is to estimate the carbon dioxide emission in China’s logistics sector, and analyze the causes for the change of carbon dioxide emission, and identify the critical factors which mainly drive the change in carbon dioxide emissions of China’s logistics industry. Design/methodology/approach: The logarithmic mean Divisia index (LMDI method has often been used to analyze decomposition of energy consumption and carbon emission due to its theoretical foundation, adaptability, ease of use and result interpretation. So we use the LMDI method to analyze the changes in carbon dioxide emission in China’s logistics industry in this paper. Findings: By analyzing carbon dioxide emission of China’s logistics, the results show that the carbon dioxide emission of logistics in China has increased by 21.5 times, from 45.1 million tons to 1014.1 million tons in the research period. The highway transport is the main contributor to carbon dioxide emission in logistics industry. The energy intensity and carbon dioxide emission factors were contributing to the reduction of carbon dioxide emission in China’s logistics industry in overall study period. Originality/value: Although there are a lot of literature analyzed carbon dioxide emission in many industry sectors, for example manufacturing, iron and steel , pulp and paper, cement, glass industry, and so on. However, few scholars researched on carbon dioxide emission in logistics industry. This the first study is in the context of carbon dioxide emission of China’s logistics industry.

  18. Carbon dioxide emission from brickfields around Bangladesh

    Directory of Open Access Journals (Sweden)

    M.A. Imran

    2014-12-01

    Full Text Available The study was undertaken at six divisions of Bangladesh to investigate the CO2 emission from brickfields. to explore the rate of carbon emission over the last 10 years, based on existing technology for brick production. The finding reveals that there were more than 45,000 Brick kilns in Bangladesh which together account for about 95% of operating kilns including Bull's Trench Kiln, Fixed Chimney Kiln, Zigzag Kiln and Hoffman Kiln. These kilns were the most carbon emitting source but it varies on fuel type, kiln type and also for location. It has been found that, maximum carbon emission area was Chittagong, which was 93.150 with percentage of last 10 years and 9.310 per cent per year. Whereas Sylhet was lower carbon emission area indicating percentage 17.172 of last 10 years and 4.218 percent per year. It has been found that total annual amount of CO2 emission for 4 types brick kilns from Dhaka, Chittagong, Rajshahi, Khulana, Sylhet and Barisal were 8.862 Mt yr-1, 10.048 Mt yr-1, 12.783 Mt yr-1, 15.250 Mt yr-1, in the year of 2002, 2005, 2007 and 2010 respectively. In Mymensingh district, the maximum CO2 emission and coal consumption was obtained in Chamak brick field, which was 1882 tons and 950 tons, respectively and minimum was obtained in Zhalak brick field, which was 1039.5 tons and 525.0 tons, respectively during the year of 2013. The percentage in last 10 years of CO2 emission was 72.784 and per cent per year 7.970, which is very alarming for us. The estimates obtained from surveys and on-site investigations indicate that these kilns consume an average of 240 tons of coal to produce 1 million bricks. This type of coal has a measured calorific value of 6,400 KJ, heating value of coal is 20.93 GJ t-1 and it produces 94.61 TJ t-1 and 56.1 TJ t-1 CO2 from coal and natural gas, respectively.

  19. Spontaneous oxygen isotope exchange between carbon dioxide and\

    Czech Academy of Sciences Publication Activity Database

    Knížek, Antonín; Zukalová, Markéta; Kavan, Ladislav; Zukal, Arnošt; Kubelík, Petr; Rojík, P.; Skřehot, P.; Ferus, Martin; Civiš, Svatopluk

    2017-01-01

    Roč. 137, MAR 2017 (2017), s. 6-10 ISSN 0169-1317 R&D Projects: GA MŠk LD14115; GA ČR(CZ) GA14-12010S; GA ČR GA13-07724S; GA MŠk(CZ) LM2015073 Institutional support: RVO:61388955 Keywords : clay * carbon dioxide * FTIR spectroscopy Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 3.101, year: 2016

  20. Effect Of Geothermal Heat Pump On Carbon Dioxide Emissions

    Directory of Open Access Journals (Sweden)

    Ahmed F. Atwan

    2015-08-01

    Full Text Available In this research the calculations of carbon dioxide emissions CO2 in summer May to September 150 day and winter seasons December to February 90 day were performed by using the coefficient of performance for each air and ground source heat pump. The place of study case take relative to solar path in to account and the study case was three halls men women and surgery halls in Al-Musayyib hospital in Babylon.

  1. Temperature measurements via narrow line laser absorption of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Wooldridge, M.S. [Texas A and M Univ., College Station, TX (United States). Dept. of Mechanical Engineering

    1996-12-31

    Theoretical development for temperature measurements via narrow line, infrared absorption of carbon dioxide (CO{sub 2}) is presented. The proposed technique is based on rapid-scanning of two adjacent absorption line shapes. Spectroscopic considerations for sensitivity to temperature measurements are discussed. Several line pairs are evaluated, and the R(58) and R(60) transitions of the (00{sup 0}1){l_arrow}(00{sup 0}0) band are suggested for use in high temperature measurements for combustion systems.

  2. Fractional Carbon Dioxide Laser in Treatment of Acne Scars

    OpenAIRE

    Petrov, Andrej

    2016-01-01

    BACKGROUND: Scars appear as a result of skin damage during the process of the skin healing. There are two types of acne scars, depending on whether there is a loss or accumulation of collagen: atrophic and hypertrophic. In 80-90% it comes to scars with loss of collagen compared to smaller number of hypertrophic scars and keloids. AIM: The aim of the study was to determine efficiency and safety of fractional carbon dioxide laser in the treatment of acne scars. MATERIAL AN...

  3. Titanium dioxide, single-walled carbon nanotube composites

    Science.gov (United States)

    Yao, Yuan; Li, Gonghu; Gray, Kimberly; Lueptow, Richard M.

    2015-07-14

    The present invention provides titanium dioxide/single-walled carbon nanotube composites (TiO.sub.2/SWCNTs), articles of manufacture, and methods of making and using such composites. In certain embodiments, the present invention provides membrane filters and ceramic articles that are coated with TiO.sub.2/SWCNT composite material. In other embodiments, the present invention provides methods of using TiO.sub.2/SWCNT composite material to purify a sample, such as a water or air sample.

  4. Extraction of olive oil with supercritical carbon dioxide / Ilana Geerdts

    OpenAIRE

    Geerdts, Ilana

    2005-01-01

    The principal objective of this study was to extract olive oil from the fruit of Olea europaea by means of supercritical carbon dioxide (sc-C02) as an alternative to traditional methods. Extractions were performed on a laboratory scale supercritical fluid extractor of the latest design, featuring three mutually independent flow systems and extremely high flow rates. A number of extraction runs based on a statistical design was performed to establish the conditions (time, pressu...

  5. The effect of carbon dioxide therapy on composite graft survival

    OpenAIRE

    Durães, Eliana Ferreira Ribeiro; Durães, Leonardo de Castro; Carneiro, Fabiana Pirani; Lino Júnior, Ruy de Souza; Sousa,João Batista de

    2013-01-01

    PURPOSE: To investigate the effect of carboxytherapy in auricular composite grafts in rabbits. METHODS: An experimental study was conducted using 20 rabbits randomly assigned to a treatment group of carboxytherapy or a control group of saline solution. In each ear, a circular graft with 1.5 cm or 2 cm of diameter was amputated and reattached. Animals underwent carbon dioxide or saline injection four times during the experiment. We analyzed clinical evolution of the animals, grafts survival, h...

  6. Clinical Correlates of Carbon Dioxide Hypersensitivity in Children.

    Science.gov (United States)

    Rappaport, Lance M; Sheerin, Christina; Carney, Dever M; Towbin, Kenneth E; Leibenluft, Ellen; Pine, Daniel S; Brotman, Melissa A; Roberson-Nay, Roxann; Hettema, John M

    2017-12-01

    Hypersensitivity to carbon dioxide (CO 2 )-enriched air may be a promising risk marker for anxiety disorders. Among adult and adolescent samples, heterogeneity in distress response to the CO 2 challenge task indexes 3 underlying classes of individuals, which distinguish between sustained and acute threat response as markers for internalizing disorders, broadly, and anxiety disorders, specifically. The present study examines latent classes in children's response to the CO 2 challenge task to clarify the association of CO 2 hypersensitivity with anxiety and internalizing symptomatology in childhood. Healthy children from a community twin sample (N = 538; age 9-13 years) rated anxious distress every 2 minutes while breathing air enriched to 7.5% CO 2 for 8 minutes. Latent growth mixture modeling evaluated potential classes of individuals with characteristic trajectories of distress during the task to clarify the association with internalizing disorder symptoms and related traits (e.g., anxiety sensitivity, irritability). Although all participants reported increased distress during the task, interindividual heterogeneity in distress indexed 3 underlying classes: a consistently low class ("low"), a consistently high class ("high"), and participants who demonstrated markedly increased acute distress ("acute"). Compared to the low class, the high class reported greater internalizing psychopathology, whereas membership in the acute class was associated with experiencing a panic-like event during the task. As in older individuals, 3 distinct trajectories emerged to capture interindividual heterogeneity in children's distress during the CO 2 challenge task. These classes were distinguished by clinical validators that reinforce the association of CO 2 hypersensitivity and internalizing disorder phenotypes in children. Copyright © 2017 American Academy of Child and Adolescent Psychiatry. All rights reserved.

  7. Study on carbon dioxide conversion by radiation

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young Hyun; Park, Geun Il; Cho, Il Hoon; Choi, Sang Do; Hong, Kwang Hee; Lee, Chang Woo

    1999-09-01

    This study was carried out to investigate the synergistic effects on the CO{sub 2} conversion by the application of semiconductor in the field of gamma-ray. Gamma-ray irradiation was performed to examine the effects of semiconductor application on CO{sub 2} conversion in water and the formation of organic material from carbonate solution. From experimental results it is clear that the supplication of semiconductor in the field of gamma-ray increases the efficiency for CO{sub 2} conversion to organic matter. Based on the obtained experimental results it is obvious that the synergistic effects of semiconductor materials in the gamma-ray field leads to increase of the CO{sub 2} conversion yield to organic matter up to 50 percent compared to the gamma-ray irradiation. The way of achieving higher activity is due to thecatalytic action of semiconductor by gamma-ray irradiation. Zr-doped TiO{sub 2} catalyst prepared by sol-gel method exhibits the higher efficiency for CO{sub 2} conversion in aqueous solution and carbonate containing solution. This effect of Zr-doping can be explained by the formation of additional defects in surface of TiO{sub 2} film. (author)

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

    Directory of Open Access Journals (Sweden)

    Elise Pendall

    Full Text Available 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 effect of these global change factors is especially uncertain because of their potential for interactions and indirectly mediated conditions such as soil moisture. Here, we present observations of CO2 fluxes from a multi-factor experiment in semi-arid grassland that suggests a potentially strong climate - carbon cycle feedback under combined elevated [CO2] and warming. Elevated [CO2] alone, and in combination with warming, enhanced ecosystem respiration to a greater extent than photosynthesis, resulting in net C loss over four years. The effect of warming was to reduce respiration especially during years of below-average precipitation, by partially offsetting the effect of elevated [CO2] on soil moisture and C cycling. Carbon losses were explained partly by stimulated decomposition of soil organic matter with elevated [CO2]. The climate - carbon cycle feedback observed in this semiarid grassland was mediated by soil water content, which was reduced by warming and increased by elevated [CO2]. Ecosystem models should incorporate direct and indirect effects of climate change on soil water content in order to accurately predict terrestrial feedbacks and long-term storage of C in soil.

  9. Irreversible climate change due to carbon dioxide emissions.

    Science.gov (United States)

    Solomon, Susan; Plattner, Gian-Kasper; Knutti, Reto; Friedlingstein, Pierre

    2009-02-10

    The severity of damaging human-induced climate change depends not only on the magnitude of the change but also on the potential for irreversibility. This paper shows that the climate change that takes place due to increases in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop. Following cessation of emissions, removal of atmospheric carbon dioxide decreases radiative forcing, but is largely compensated by slower loss of heat to the ocean, so that atmospheric temperatures do not drop significantly for at least 1,000 years. Among illustrative irreversible impacts that should be expected if atmospheric carbon dioxide concentrations increase from current levels near 385 parts per million by volume (ppmv) to a peak of 450-600 ppmv over the coming century are irreversible dry-season rainfall reductions in several regions comparable to those of the "dust bowl" era and inexorable sea level rise. Thermal expansion of the warming ocean provides a conservative lower limit to irreversible global average sea level rise of at least 0.4-1.0 m if 21st century CO(2) concentrations exceed 600 ppmv and 0.6-1.9 m for peak CO(2) concentrations exceeding approximately 1,000 ppmv. Additional contributions from glaciers and ice sheet contributions to future sea level rise are uncertain but may equal or exceed several meters over the next millennium or longer.

  10. [Thoracoscopic thymectomy with carbon dioxide insufflation in the mediastinum].

    Science.gov (United States)

    Ferrero-Coloma, C; Navarro-Martinez, J; Bolufer, S; Rivera-Cogollos, M J; Alonso-García, F J; Tarí-Bas, M I

    2015-02-01

    The case is presented of a 71 year-old male, diagnosed with a thymoma. A thoracoscopic thymectomy was performed using the carbon dioxide insufflation technique in the mediastinum. During the procedure, while performing one-lung ventilation, the patient's respiration worsened. The contralateral lung had collapsed, as carbon dioxide was travelling from the mediastinum to the thorax through the opened pleura. Two-lung ventilation was decided upon, which clearly improved oxygenation in the arterial gases and airway pressures. Both pH and pCO2 stabilized. The surgical approach and the carbon dioxide technique were continued because 2-lung ventilation did not affect the surgical procedure. This technique has many serious complications and it should always be performed using 2-lung ventilation. Copyright © 2014 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  11. Nanostructured membrane material designed for carbon dioxide separation

    KAUST Repository

    Yave, Wilfredo

    2010-03-15

    In this work carbon dioxide selective membrane materials from a commercially available poly(amide-b-ethylene oxide) (Pebax (R), Arkema) blended with polyethylene glycol ethers are presented. The preferred PEG-ether was PEG-dimethylether (PEG-DME). PEG-DME is well known as a physical solvent for acid gas absorption. It is used under the trade name Genosorb (R) in the Selexol (R) process (UOP) for acid gas removal from natural gas and synthesis gas. The combination of the liquid absorbent with the multiblock copolymer resulted in mechanically stable films with superior CO(2) separation properties. The addition of 50 wt.% PEG-DME to the copolymer resulted in a 8-fold increase of the carbon dioxide permeability; the CO(2)/H(2)-selectivity increased simultaneously from 9.1 to 14.9. It is shown that diffusivity as well as solubility of carbon dioxide is strongly increased by the blending of the copolymer with PEG-ethers. (c) 2009 Elsevier B.V. All rights reserved.

  12. Developing a molecular platform for potential carbon dioxide fixing

    DEFF Research Database (Denmark)

    Mikkelsen, Mette; Jørgensen, Mikkel; Krebs, Frederik C

    2010-01-01

    This paper presents an attempt to develop a new system for fixing carbon dioxide from the atmosphere. The proposed molecular system has been designed to have the capacity to spontaneously bind CO2 from the atmosphere with high affinity. The molecular system is furthermore designed to have...... the ability to liberate CO2 at a later stage in the process, i.e., in a separate compartment. The liberated CO2 presents a carbon neutral way of obtaining pure CO2. The proposed molecular system is based on a small stable organic molecule that potentially have two forms: one without bound CO2 and one...

  13. Fluid phase equilibria during propylene carbonate synthesis from propylene oxide in carbon dioxide medium

    DEFF Research Database (Denmark)

    Gharnati, Loubna; Musko, Nikolai; Jensen, Anker Degn

    2013-01-01

    In the present study the influence of the amount of carbon dioxide on the catalytic performance during the propylene carbonate synthesis from propylene oxide and CO2 was investigated. The reaction was performed in high-pressure batch autoclaves using immobilized 1-hydroxyethyl-9-propyl...

  14. More feed efficient sheep produce less methane and carbon dioxide when eating high-quality pellets.

    Science.gov (United States)

    Paganoni, B; Rose, G; Macleay, C; Jones, C; Brown, D J; Kearney, G; Ferguson, M; Thompson, A N

    2017-09-01

    easier to measure than feed intake and has strong phenotypic and genetic correlations with feed intake. Furthermore, selection for feed intake, feed efficiency, methane, and carbon dioxide can be done early in sheep at postweaning age or hoggets. This early selection reduces the generation interval for breeding, thereby increasing response to selection.

  15. The lifetime of excess atmospheric carbon dioxide

    Science.gov (United States)

    Moore, Berrien; Braswell, B. H.

    1994-03-01

    We explore the effects of a changing terrestrial biosphere on the atmospheric residence time of CO2 using three simple ocean carbon cycle models and a model of global terrestrial carbon cycling. We find differences in model behavior associated with the assumption of an active terrestrial biosphere (forest regrowth) and significant differences if we assume a donor-dependent flux from the atmosphere to the terrestrial component (e.g., a hypothetical terrestrial fertilization flux). To avoid numerical difficulties associated with treating the atmospheric CO2 decay (relaxation) curve as being well approximated by a weighted sum of exponential functions, we define the single half-life as the time it takes for a model atmosphere to relax from its present-day value half way to its equilibrium pCO2 value. This scenario-based approach also avoids the use of unit pulse (Dirac Delta) functions which can prove troublesome or unrealistic in the context of a terrestrial fertilization assumption. We also discuss some of the numerical problems associated with a conventional lifetime calculation which is based on an exponential model. We connect our analysis of the residence time of CO2 and the concept of single half-life to the residence time calculations which are based on using weighted sums of exponentials. We note that the single half-life concept focuses upon the early decline of CO2 under a cutoff/decay scenario. If one assumes a terrestrial biosphere with a fertilization flux, then our best estimate is that the single half-life for excess CO2 lies within the range of 19 to 49 years, with a reasonable average being 31 years. If we assume only regrowth, then the average value for the single half-life for excess CO2 increases to 72 years, and if we remove the terrestrial component completely, then it increases further to 92 years.

  16. Electrocatalytic reduction of carbon dioxide under plasma DBD process

    Science.gov (United States)

    Amouroux, Jacques; Cavadias, Simeon

    2017-11-01

    Carbon dioxide can be converted, by reaction with hydrogen, into fine chemicals and liquid fuels such as methanol and DME. Methane production by the Sabatier reaction opens the way of carbon recycling for a circular economy of carbon resources. The catalytic process of methanation of carbon dioxide produces two molecules of water as a by-product. A current limitation in the CO2 methanation is the ageing of catalysts, mainly due to water adsorption during the process. To avoid this adsorption, the process is operated at high temperature (300 °C–400 °C), leading to carbon deposition on the catalyst and its deactivation. To overcome this problem, a methanation plasma-catalytic process has been developed, which achieves high CO2 conversion rate (80%), and a selectivity close to 100%, working from room temperature to 150 °C, instead of 300 °C–400 °C for the thermal catalytic process. The main characteristics of this process are high-voltage pulses of few nanoseconds duration, activating the adsorption of CO2 in bent configuration and the polarization of the catalyst. The key step in this process is the desorption of water from the polarized catalyst. The high CO2 conversion at low temperature could be explained by the creation of a plasma inside the nanopores of the catalyst.

  17. Investigations about the quantitative changes of carbon dioxide production in humans. Report 2: Carbon dioxide production during fever and its relationship with heat production

    Science.gov (United States)

    Liebermeister, C.

    1978-01-01

    Investigations are cited and explained for carbon dioxide production during fever and its relationship with heat production. The general topics of discussion are: (1) carbon dioxide production for alternating fever attacks; (2) heat balance during the perspiration phase; (3) heat balance during the chill phase; (4) the theory of fever; and (5) chill phase for other fever attacks.

  18. End-tidal carbon dioxide (ETCO2) can replace methods for measuring partial pressure of carbon dioxide (PCO2) in pigs

    DEFF Research Database (Denmark)

    Alstrup, Aage Kristian Olsen

    2017-01-01

    We compared end-tidal carbon dioxide (ETCO2) with partial pressure of carbon dioxide (PCO2) in domestic pigs anesthetized for neuroscience. There was good agreement between ETCO2 and PCO2 under both hypocapnia, normocapnia, and hypercapnia conditions. ETCO2 saves time by continually providing...

  19. Kinetic of formation for single carbon dioxide and mixed carbon dioxide and tetrahydrofuran hydrates in water and sodium chloride aqueous solution

    NARCIS (Netherlands)

    Sabil, K.M.; Duarte, A.R.C.; Zevenbergen, J.F.; Ahmad, M.M.; Yusup, S.; Omar, A.A.; Peters, C.J.

    2010-01-01

    A laboratory-scale reactor system is built and operated to measure the kinetic of formation for single and mixed carbon dioxide-tetrahydrofuran hydrates. The T-cycle method, which is used to collect the kinetic data, is briefly discussed. For single carbon dioxide hydrate, the induction time

  20. Identifying Significant Changes in Cerebrovascular Reactivity to Carbon Dioxide.

    Science.gov (United States)

    Sobczyk, O; Crawley, A P; Poublanc, J; Sam, K; Mandell, D M; Mikulis, D J; Duffin, J; Fisher, J A

    2016-05-01

    Changes in cerebrovascular reactivity can be used to assess disease progression and response to therapy but require discrimination of pathology from normal test-to-test variability. Such variability is due to variations in methodology, technology, and physiology with time. With uniform test conditions, our aim was to determine the test-to-test variability of cerebrovascular reactivity in healthy subjects and in patients with known cerebrovascular disease. Cerebrovascular reactivity was the ratio of the blood oxygen level-dependent MR imaging response divided by the change in carbon dioxide stimulus. Two standardized cerebrovascular reactivity tests were conducted at 3T in 15 healthy men (36.7 ± 16.1 years of age) within a 4-month period and were coregistered into standard space to yield voxelwise mean cerebrovascular reactivity interval difference measures, composing a reference interval difference atlas. Cerebrovascular reactivity interval difference maps were prepared for 11 male patients. For each patient, the test-retest difference of each voxel was scored statistically as z-values of the corresponding voxel mean difference in the reference atlas and then color-coded and superimposed on the anatomic images to create cerebrovascular reactivity interval difference z-maps. There were no significant test-to-test differences in cerebrovascular reactivity in either gray or white matter (mean gray matter, P = .431; mean white matter, P = .857; paired t test) in the healthy cohort. The patient cerebrovascular reactivity interval difference z-maps indicated regions where cerebrovascular reactivity increased or decreased and the probability that the changes were significant. Accounting for normal test-to-test differences in cerebrovascular reactivity enables the assessment of significant changes in disease status (stability, progression, or regression) in patients with time. © 2016 by American Journal of Neuroradiology.

  1. Carbon Dioxide Fixation by Lupin Root Nodules

    Science.gov (United States)

    Laing, William A.; Christeller, John T.; Sutton, William D.

    1979-01-01

    Labeling studies using detached lupin (Lupinus angustifolius) nodules showed that over times of less than 3 minutes, label from [3,4-14C]glucose was incorporated into amino acids, predominantly aspartic acid, to a much greater extent than into organic acids. Only a slight preferential incorporation was observed with [1-14C]- and [6-14C]glucose, while with [U-14C]-glucose more label was incorporated into organic acids than into amino acids at all labeling times. These results are consistent with a scheme whereby the “carbon skeletons” for amino acid synthesis are provided by the phosphoenolpyruvate carboxylase reaction. A comparison of 14CO2 release from nodules supplied with [1-14C]- and [6-14C]glucose indicated that the oxidative pentose phosphate pathway accounted for less than 6% of glucose metabolism. Several enzymes of the oxidative pentose phosphate and glycolytic pathways were assayed in vitro using the 12,000g supernatant fraction from nodule homogenates. In all cases, the specific activities were adequate to account for the calculated in vivo fluxes. Three out of four diverse treatments that inhibited nodule nitrogen fixation also inhibited nodule CO2 fixation, and in the case of the fourth treatment, replacement of N2 with He, it was shown that the normal entry of label from exogenous 14CO2 into the nodule amino acid pool was strongly inhibited. PMID:16660746

  2. Carbon dioxide free production of hydrogen

    Science.gov (United States)

    Stoppel, L.; Fehling, T.; Geißler, T.; Baake, E.; Wetzel, T.

    2017-07-01

    The present report summarizes the theoretical modelling and experimental investigation results of the study on the direct thermal methane cracking. This work is a part of the LIMTECH-Project (Liquid Metal Technologies) funded of Helmholtz Alliance and was carried out from 2012 to 2017. The Project-part B5 “CO2-free production of hydrogen” focused on experimental testing and particularly on modelling the novel methane cracking method based on liquid metal technology. The new method uses a bubble column reactor, filled with liquid metal, where both the chemical reaction of methane decomposition and the separation of gas fraction from solid carbon occur. Such reactor system was designed and built in the liquid metal laboratory (KALLA) at KIT. The influences of liquid metal temperature distribution in reactor and feed gas flow rate on methane conversion ratio were investigated experimentally at the temperature range from 930°C to 1175 °C and methane flow rate at the reactor inlet from 50 to 200 mLn/min. In parallel with experimental investigations, a thermochemical model, giving insight in the influence of the above mentioned parameters has been developed at KIT and a CFD model was developed at LUH to get an overview about the bubble dynamics in the reaction system. The influence of different bubble sizes and shapes, multi-inlet coalescence effects as well as the potential of electromagnetic stirring have been investigated.

  3. Growth enhancement by soil derived carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Grodzinski, B.; Wallis, M.; O' Sullivan, J. (Univ. of Guelph, Ontario (Canada))

    1989-04-01

    The objective of this study was to investigate the role which naturally evolved CO{sub 2} from the soil can play in the early growth and establishment of vegetable transplants in the field. Two planting dates were utilized to examine the effects of the time of tunnel placement on development of a crop of bell peppers, Capsicum annuum L. Ambient CO{sub 2} levels were 340 {plus minus} 4 ppm. In the first 3 weeks of spring (May) CO levels 2 to 3 cm above the soil surface were 420 to 480 ppm. Inside plastic tunnels the upward flux of CO{sub 2} evolved from the soil was restricted effectively raising the tunnel atmosphere to over 3000 ppm even at midday. Data from parallel field and controlled environment chamber experiments support the view that 25-40% of the increase in seedling growth in the field tunnels in the spring was due to enhanced photosynthesis and carbon partitioning into both sugars and starch not merely the elevated temperatures associated with protected structures.

  4. Application of a systematic methodology for sustainable carbon dioxide utilization process design

    DEFF Research Database (Denmark)

    Plaza, Cristina Calvera; Frauzem, Rebecca; Gani, Rafiqul

    there are two methods of reducing carbon dioxide emissions, carbon capture and storage (CCS) and carbon capture and utilization (CCU), CCU is considered promising as it makes further use of the carbon dioxide as a solvent, raw material, and reagent to produce valuable products [1]. Using such utilization...... processes, the emissions can be reduced as they are being utilized and profit can be obtained, or the cost of operation for the carbon dioxide treatment can be returned, through this utilization process. In order to systematically reduce such emissions, carbon capture and utilization is considered rather...... than carbon capture and storage. To achieve this a methodology is developed to design sustainable carbon dioxide utilization processes. First, the information on the possible utilization alternatives is collected, including the economic potential of the process and the carbon dioxide emissions...

  5. The scaling of carbon dioxide release and respiratory water loss in flying fruit flies (Drosophila spp.)

    OpenAIRE

    Lehmann, Fritz-Olaf; Dickinson, Michael H.; Staunton, Jocelyn

    2000-01-01

    By simultaneously measuring carbon dioxide release, water loss and flight force in several species of fruit flies in the genus Drosophila, we have investigated respiration and respiratory transpiration during elevated locomotor activity. We presented tethered flying flies with moving visual stimuli in a virtual flight arena, which induced them to vary both flight force and energetic output. In response to the visual motion, the flies altered their energetic output as measured by changes in ca...

  6. Selected constituents in the smokes of foreign commercial cigaretts: tar, nicotine, carbon monoxide, and carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, R.A.; Quincy, R.B.; Guerin, M.R.

    1979-05-01

    The tar, nicotine, carbon monoxide, and carbon dioxide contents of the smokes of 220 brands of foreign commercial cigarettes are reported. In some instances, filter cigarettes of certain brands were found to deliver as much or more smoke constituents than their nonfilter counterparts. Also, data indicated that there can be a great variation in the tar, nicotine, or carbon monoxide content of the smoke of samples of a given brand of cigarettes, depending on the nation in which they are purchased. 24 tables.

  7. Hydrogen storage and delivery: the carbon dioxide - formic acid couple.

    Science.gov (United States)

    Laurenczy, Gábor

    2011-01-01

    Carbon dioxide and the carbonates, the available natural C1 sources, can be easily hydrogenated into formic acid and formates in water; the rate of this reduction strongly depends on the pH of the solution. This reaction is catalysed by ruthenium(II) pre-catalyst complexes with a large variety of water-soluble phosphine ligands; high conversions and turnover numbers have been realised. Although ruthenium(II) is predominant in these reactions, the iron(II) - tris[(2-diphenylphosphino)-ethyl]phosphine (PP3) complex is also active, showing a new perspective to use abundant and inexpensive iron-based compounds in the CO2 reduction. In the catalytic hydrogenation cycles the in situ formed metal hydride complexes play a key role, their structures with several other intermediates have been proven by multinuclear NMR spectroscopy. In the other hand safe and convenient hydrogen storage and supply is the fundamental question for the further development of the hydrogen economy; and carbon dioxide has been recognised to be a viable H2 vector. Formic acid--containing 4.4 weight % of H2, that is 53 g hydrogen per litre--is suitable for H2 storage; we have shown that in aqueous solutions it can be selectively decomposed into CO-free (CO carbonate solution, opening the way to use cheap, non-noble metal based catalysts for this reaction, too.

  8. Carbon dioxide production during mechanical ventilation

    DEFF Research Database (Denmark)

    Henneberg, S; Söderberg, D; Groth, T

    1987-01-01

    Because of large stores of CO2 in different body tissues, metabolic change cannot be detected by measuring gas exchange until the CO2 stores have adapted to the new situation. Similarly, changes in the CO2 stores not due to metabolic alterations, may lead to error in gas exchange measurements. We...... continuously by a mass spectrometer. Signals from this instrument, together with gas-volume signals from the ventilator, were fed to a computer for calculation of VO2 and VCO2. Twenty to 120 min were required to reach a stable level, depending on the patient's size and circulatory response. Similar results...... and awareness. Ventilatory variables should not be changed substantially during the 90-min period before gas sampling. Cardiac output and muscle blood flow should not have changed 2 to 3 h before measuring RQ. If muscle blood flow is low, the stable periods for body temperature and ventilatory variables should...

  9. Apparatus and method for removing solvent from carbon dioxide in resin recycling system

    Science.gov (United States)

    Bohnert, George W [Harrisonville, MO; Hand, Thomas E [Lee's Summit, MO; DeLaurentiis, Gary M [Jamestown, CA

    2009-01-06

    A two-step resin recycling system and method solvent that produces essentially contaminant-free synthetic resin material. The system and method includes one or more solvent wash vessels to expose resin particles to a solvent, the solvent contacting the resin particles in the one or more solvent wash vessels to substantially remove contaminants on the resin particles. A separator is provided to separate the solvent from the resin particles after removal from the one or more solvent wash vessels. The resin particles are next exposed to carbon dioxide in a closed loop carbon dioxide system. The closed loop system includes a carbon dioxide vessel where the carbon dioxide is exposed to the resin, substantially removing any residual solvent remaining on the resin particles after separation. A separation vessel is also provided to separate the solvent from the solvent laden carbon dioxide. Both the carbon dioxide and the solvent are reused after separation in the separation vessel.

  10. Atmospheric carbon dioxide and the global carbon cycle

    Energy Technology Data Exchange (ETDEWEB)

    Trabalka, J R [ed.

    1985-12-01

    This state-of-the-art volume presents discussions on the global cycle of carbon, the dynamic balance among global atmospheric CO2 sources and sinks. Separate abstracts have been prepared for the individual papers. (ACR)

  11. Adding value to carbon dioxide from ethanol fermentations.

    Science.gov (United States)

    Xu, Yixiang; Isom, Loren; Hanna, Milford A

    2010-05-01

    Carbon dioxide (CO(2)) from ethanol production facilities is increasing as more ethanol is produced for alternative transportation fuels. CO(2) produced from ethanol fermentation processes is of high purity and is nearly a saturated gas. Such highly-concentrated source of CO(2) is a potential candidate for capture and utilization by the CO(2) industry. Quantity, quality and capture of CO(2) from ethanol fermentations are discussed in this review. The established and emerging value-added opportunities and markets for CO(2) from ethanol plants also are reviewed. The majority of CO(2) applications are dedicated to serving carbonated beverage and food processing and preservation markets. Beyond traditional merchant markets, the potential for exploring some fresh and profitable markets are discussed including carbon sources in chemical industries for the following: enhanced oil recovery; production of chemicals, fuels, and polymers; and production of algae-based biofuels through CO(2) fixation by microalgae. Copyright 2010 Elsevier Ltd. All rights reserved.

  12. Carbon dioxide effects research and assessment program. A comprehensive plan. Part I. The global carbon cycle and climatic effects of increasing carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Slade, David H.

    1980-08-01

    Initial plans for research of the carbon dioxide (CO/sub 2/) and climate issue were prepared in 1978 and were reviewed extensively at that time by federal agencies and members of the scientific community. Since then the plans have been used to guide early phases of the Department of Energy's and the nation's efforts related to this issue. This document represents a revision of the 1978 plan to (a) reflect recent ideas and strategies for carbon cycle research, and (b) expand the scope of research on climatic responses to increasing atmospheric concentrations of CO/sub 2/. The revised plan takes into account a number of investigations already being supported by various agencies, and it attempts to build on or add to existing research where there is a crucial need for information directly related to the CO/sub 2/ issue. It should be recognized that this document is the first section of a comprehensive plan on the overall consequences of increasing concentrations of CO/sub 2/, and includes guidelines for research on the Global Carbon Cycle and Climatic Effects of Increasing CO/sub 2/.

  13. Recycling Carbon Dioxide into Sustainable Hydrocarbon Fuels: Electrolysis of Carbon Dioxide and Water

    Science.gov (United States)

    Graves, Christopher Ronald

    Great quantities of hydrocarbon fuels will be needed for the foreseeable future, even if electricity based energy carriers begin to partially replace liquid hydrocarbons in the transportation sector. Fossil fuels and biomass are the most common feedstocks for production of hydrocarbon fuels. However, using renewable or nuclear energy, carbon dioxide and water can be recycled into sustainable hydrocarbon fuels in non-biological processes which remove oxygen from CO2 and H2O (the reverse of fuel combustion). Capture of CO2 from the atmosphere would enable a closed-loop carbon-neutral fuel cycle. The purpose of this work was to develop critical components of a system that recycles CO2 into liquid hydrocarbon fuels. The concept is examined at several scales, beginning with a broad scope analysis of large-scale sustainable energy systems and ultimately studying electrolysis of CO 2 and H2O in high temperature solid oxide cells as the heart of the energy conversion, in the form of three experimental studies. The contributions of these studies include discoveries about electrochemistry and materials that could significantly improve the overall energy use and economics of the CO2-to-fuels system. The broad scale study begins by assessing the sustainability and practicality of the various energy carriers that could replace petroleum-derived hydrocarbon fuels, including other hydrocarbons, hydrogen, and storage of electricity on-board vehicles in batteries, ultracapacitors, and flywheels. Any energy carrier can store the energy of any energy source. This sets the context for CO2 recycling -- sustainable energy sources like solar and wind power can be used to provide the most energy-dense, convenient fuels which can be readily used in the existing infrastructure. The many ways to recycle CO2 into hydrocarbons, based on thermolysis, thermochemical loops, electrolysis, and photoelectrolysis of CO2 and/or H 2O, are critically reviewed. A process based on high temperature co

  14. Life cycle study. Carbon dioxide emissions lower in electric heating than in oil heating

    Energy Technology Data Exchange (ETDEWEB)

    Heikkinen, A.; Jaervinen, P.; Nikula, A.

    1996-11-01

    A primary objective of energy conservation is to cut carbon dioxide emissions. A comparative study on the various heating forms, based on the life cycle approach, showed that the carbon dioxide emissions resulting form heating are appreciably lower now that electric heating has become more common. The level of carbon dioxide emissions in Finland would have been millions of tonnes higher had oil heating been chosen instead of electric heating. (orig.)

  15. Solid carbon dioxide to promote the extraction of extra-virgin olive oil

    OpenAIRE

    Zinnai, A.; Venturi, F; Quartacci, M.F.; Sanmartin, C.; Favati, F.; Andrich, G.

    2016-01-01

    The use of solid carbon dioxide (dry ice) as a cryogen is widespread in the food industry to produce high quality wines, rich in color and perfumes. The direct addition of carbon dioxide to olives in the solid state before milling represents a fundamental step which characterizes this innovative extraction system. At room temperature conditions solid carbon dioxide evolves directly into the air phase (sublimation), and the direct contact between the cryogen and the olives induces a partial so...

  16. Mechanistical studies on the formation of carbon dioxide in extraterrestrial carbon monoxide ice analog samples.

    Science.gov (United States)

    Bennett, Chris J; Jamieson, Corey S; Kaiser, Ralf I

    2009-06-07

    Binary ice mixtures of two carbon monoxide isotopomers, (13)C(16)O and (12)C(18)O, were subjected at 10 K to energetic electrons to investigate the interaction of ionizing radiation with extraterrestrial, carbon monoxide bearing ices. The chemical modifications were monitored on line and in situ via absorption-reflection-absorption Fourier transform infrared spectroscopy as well as in the gas-phase via a quadrupole mass spectrometer. Detected products include two newly formed carbon monoxide isotopomers ((12)C(16)O and (13)C(18)O), carbon dioxide ((12)C(16)O(2), (12)C(18)O(16)O, (12)C(18)O(2), (13)C(16)O(2), (13)C(18)O(16)O, and (13)C(18)O(2)), and dicarbon monoxide ((12)C(13)C(16)O and (13)C(13)C(16)O). Kinetic profiles of carbon monoxide and of carbon dioxide were extracted and fit to derive reaction mechanisms and information on the decomposition of carbon monoxide and on the formation of carbon dioxide in extraterrestrial ice analog samples.

  17. Metal-organic frameworks for electrocatalytic reduction of carbon dioxide.

    Science.gov (United States)

    Kornienko, Nikolay; Zhao, Yingbo; Kley, Christopher S; Zhu, Chenhui; Kim, Dohyung; Lin, Song; Chang, Christopher J; Yaghi, Omar M; Yang, Peidong

    2015-11-11

    A key challenge in the field of electrochemical carbon dioxide reduction is the design of catalytic materials featuring high product selectivity, stability, and a composition of earth-abundant elements. In this work, we introduce thin films of nanosized metal-organic frameworks (MOFs) as atomically defined and nanoscopic materials that function as catalysts for the efficient and selective reduction of carbon dioxide to carbon monoxide in aqueous electrolytes. Detailed examination of a cobalt-porphyrin MOF, Al2(OH)2TCPP-Co (TCPP-H2 = 4,4',4″,4‴-(porphyrin-5,10,15,20-tetrayl)tetrabenzoate) revealed a selectivity for CO production in excess of 76% and stability over 7 h with a per-site turnover number (TON) of 1400. In situ spectroelectrochemical measurements provided insights into the cobalt oxidation state during the course of reaction and showed that the majority of catalytic centers in this MOF are redox-accessible where Co(II) is reduced to Co(I) during catalysis.

  18. Carbon dioxide emissions from estuaries of northern and northeastern Brazil

    Science.gov (United States)

    Noriega, Carlos; Araujo, Moacyr

    2014-01-01

    The carbon dioxide flux through the air–water interface of coastal estuarine systems must be quantified to understand the regional balance of carbon and its transport through adjacent coastal regions. We estimated and calculated the emissions of carbon dioxide (FCO2) and the partial pressure of CO2 (pCO2) values in 28 estuarine environments at a variety of spatial scales in the northern and northeastern regions of Brazil. The results showed a mean FCO2 (water to air) of 55 ± 45 mmol·m−2·d−1. Additionally, a negative correlation between dissolved oxygen saturation and pCO2 was observed, indicating a control by biological processes and especially by organic matter degradation. This leads to increased dissolved CO2 concentration in estuarine waters which results in a pCO2 that reached 8,638 μatm. Our study suggests that northern and northeastern Brazilian estuaries act as sources of atmospheric CO2. The range of pCO2 observed were similar to those found in inner estuaries in other places around the world, with the exception of a few semi-arid estuaries (Köppen climate classification – BSh) in which record low levels of pCO2 have been detected. PMID:25145418

  19. Lidar detection of carbon dioxide in volcanic plumes

    Science.gov (United States)

    Fiorani, Luca; Santoro, Simone; Parracino, Stefano; Maio, Giovanni; Del Franco, Mario; Aiuppa, Alessandro

    2015-06-01

    Volcanic gases give information on magmatic processes. In particular, anomalous releases of carbon dioxide precede volcanic eruptions. Up to now, this gas has been measured in volcanic plumes with conventional measurements that imply the severe risks of local sampling and can last many hours. For these reasons and for the great advantages of laser sensing, the thorough development of volcanic lidar has been undertaken at the Diagnostics and Metrology Laboratory (UTAPRAD-DIM) of the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA). In fact, lidar profiling allows one to scan remotely volcanic plumes in a fast and continuous way, and with high spatial and temporal resolution. Two differential absorption lidar instruments will be presented in this paper: BILLI (BrIdge voLcanic LIdar), based on injection seeded Nd:YAG laser, double grating dye laser, difference frequency mixing (DFM) and optical parametric amplifier (OPA), and VULLI (VULcamed Lidar), based on injection seeded Nd:YAG laser and optical parametric oscillator (OPO). The first one is funded by the ERC (European Research Council) project BRIDGE and the second one by the ERDF (European Regional Development Fund) project VULCAMED. While VULLI has not yet been tested in a volcanic site, BILLI scanned the gas emitted by Pozzuoli Solfatara (Campi Flegrei volcanic area, Naples, Italy) during a field campaign carried out from 13 to 17 October 2014. Carbon dioxide concentration maps were retrieved remotely in few minutes in the crater area. Lidar measurements were in good agreement with well-established techniques, based on different operating principles. To our knowledge, it is the first time that carbon dioxide in a volcanic plume is retrieved by lidar, representing the first direct measurement of this kind ever performed on an active volcano and showing the high potential of laser remote sensing in geophysical research.

  20. Yeast-based microporous carbon materials for carbon dioxide capture.

    Science.gov (United States)

    Shen, Wenzhong; He, Yue; Zhang, Shouchun; Li, Junfen; Fan, Weibin

    2012-07-01

    A hierarchical microporous carbon material with a Brunauer-Emmett-Teller surface area of 1348 m(2) g(-1) and a pore volume of 0.67 cm(3) g(-1) was prepared from yeast through chemical activation with potassium hydroxide. This type of material contains large numbers of nitrogen-containing groups (nitrogen content >5.3 wt%), and, consequently, basic sites. As a result, this material shows a faster adsorption rate and a higher adsorption capacity of CO(2) than the material obtained by directly carbonizing yeast under the same conditions. The difference is more pronounced in the presence of N(2) or H(2)O, showing that chemical activation of discarded yeast with potassium hydroxide could afford high-performance microporous carbon materials for the capture of CO(2). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Relationship between Sampling Distance and Carbon Dioxide Emission under Oil Palm Plantation

    Directory of Open Access Journals (Sweden)

    Ai Dariah

    2013-05-01

    Full Text Available A carbon dioxide emission on peatland under oil palm plantation was highly varied due to many factors involved. The objectives of the research were to evaluate the effect of sampling distance from center of oil palm tree on Carbon dioxide flux, and to study the factors that cause variability of carbon dioxide flux on peatland under oil palm plantation. The study was conducted on peatland at Arang-Arang Village, Kumpek Ulu Sub-District, Muaro Jambi District, Jambi Province, on six-years old oil palm plantation. The study was conducted in the form of observational exploratory. Emission measurements were performed on 5 selected oil palm trees at points within 100, 150, 200, 250, 300, 350, and 400 cm from the center of trunk. Carbon dioxide flux was measured using (IRGA, Li-COR 820. The results showed that there was significant correlation between the distance of sampling from center of oil palm tree and Carbon dioxide flux. The farther distance from the tree, the more decreased of Carbon dioxide flux . Before applying fertilizer, variability of soil fertility was not significantly correlated with the flux of Carbon dioxide, so the difference of Carbon dioxide flux based on distance sampling can be caused by root distribution factor. After fertilizer application, variability of Carbon dioxide flux under the oil palm tree were not only affected by differences in root distribution but also greatly influenced by fertilization.

  2. High-resolution carbon dioxide concentration record 650,000-800,000 years before present

    DEFF Research Database (Denmark)

    Lüthi, Dieter; Le Floch, Martine; Bereiter, Bernhard

    2008-01-01

    Changes in past atmospheric carbon dioxide concentrations can be determined by measuring the composition of air trapped in ice cores from Antarctica. So far, the Antarctic Vostok and EPICA Dome C ice cores have provided a composite record of atmospheric carbon dioxide levels over the past 650......,000 years. Here we present results of the lowest 200 m of the Dome C ice core, extending the record of atmospheric carbon dioxide concentration by two complete glacial cycles to 800,000 yr before present. From previously published data and the present work, we find that atmospheric carbon dioxide...

  3. Carbon Dioxide and Nitrogen Infused Compressed Air Foam for Depopulation of Caged Laying Hens

    Science.gov (United States)

    Gurung, Shailesh; White, Dima; Archer, Gregory; Styles, Darrel; Zhao, Dan; Farnell, Yuhua; Byrd, James; Farnell, Morgan

    2018-01-01

    Simple Summary Compressed air, detergent, and water make up compressed air foam. Our laboratory has previously reported that compressed air foam may be an effective method for mass depopulation of caged layer hens. Gases, such as carbon dioxide and nitrogen, have also been used for poultry euthanasia and depopulation. The objective of this study was to produce compressed air foam infused with carbon dioxide or nitrogen to compare its efficacy against foam with air and gas inhalation methods (carbon dioxide or nitrogen) for depopulation of caged laying hens. The study showed that a carbon dioxide-air mixture or 100% nitrogen can replace air to make compressed air foam. However, the foam with carbon dioxide had poor foam quality compared to the foam with air or nitrogen. The physiological stress response of hens subjected to foam treatments with and without gas infusion did not differ significantly. Hens exposed to foam with nitrogen died earlier as compared to methods such as foam with air and carbon dioxide. The authors conclude that infusion of nitrogen into compressed air foam results in better foam quality and shortened time to death as compared to the addition of carbon dioxide. Abstract Depopulation of infected poultry flocks is a key strategy to control and contain reportable diseases. Water-based foam, carbon dioxide inhalation, and ventilation shutdown are depopulation methods available to the poultry industry. Unfortunately, these methods have limited usage in caged layer hen operations. Personnel safety and welfare of birds are equally important factors to consider during emergency depopulation procedures. We have previously reported that compressed air foam (CAF) is an alternative method for depopulation of caged layer hens. We hypothesized that infusion of gases, such as carbon dioxide (CO2) and nitrogen (N2), into the CAF would reduce physiological stress and shorten time to cessation of movement. The study had six treatments, namely a negative control

  4. Extraction of heavy oil by supercritical carbon dioxide

    DEFF Research Database (Denmark)

    Rudyk, Svetlana Nikolayevna; Spirov, Pavel; Søgaard, Erik Gydesen

    2010-01-01

    The present study deals with the extraction of heavy oil by supercritical carbon dioxide at the pressure values changing from 16 to 56 MPa at the fixed value of temperature: 60oC. The amount of the recovered liquid phase of oil was calculated as a percentage of the extracted amount to the initial...... to apply it for the efficient displacement of oil through CO2 injection. A much higher recovery rate of 48% for liquid phase and 27% for the gas phase was observed at the pressure of 56 MPa. That shows that supercritical CO2 can provide high recovery rates when applied to heavy oil, facilitating...

  5. Drivers of seasonality in Arctic carbon dioxide fluxes

    DEFF Research Database (Denmark)

    Mbufong, Herbert Njuabe

    and the potential for widespread feedbacks with global consequences. In this thesis, I present and discuss the findings of an investigation of comparable drivers of the seasonality in carbon dioxide (CO2) fluxes across heterogeneous Arctic tundra ecosystems. Due to the remoteness and the harsh climatic conditions...... that monitoring, modelling and manipulation experiments of drivers of greenhouse gas fluxes be intensified across the globe. The Arctic tundra represents an important biome in the context of global climate change. This is because of the highly sensitive nature of the Arctic tundra to climatic perturbations...

  6. Chemical looping integration with a carbon dioxide gas purification unit

    Science.gov (United States)

    Andrus, Jr., Herbert E.; Jukkola, Glen D.; Thibeault, Paul R.; Liljedahl, Gregory N.

    2017-01-24

    A chemical looping system that contains an oxidizer and a reducer is in fluid communication with a gas purification unit. The gas purification unit has at least one compressor, at least one dryer; and at least one distillation purification system; where the gas purification unit is operative to separate carbon dioxide from other contaminants present in the flue gas stream; and where the gas purification unit is operative to recycle the contaminants to the chemical looping system in the form of a vent gas that provides lift for reactants in the reducer.

  7. Distribution of Carbon Dioxide Produced by People in a Room:

    DEFF Research Database (Denmark)

    Naydenov, Kiril Georgiev; Baránková, Petra; Sundell, Jan

    2004-01-01

    Carbon dioxide exhaled by people can be used as a tracer gas for air change measurements in homes. Good mixing of tracer gas with room air is a necessary condition to obtain accurate results. However, the use of fans to ensure mixing is inconvenient. The natural room distribution of metabolic CO2...... was detected in both studies when constant CO2 emission was obtained. Several critical points of insufficient mixing were identified. If such locations are avoided, additional mixing may not be necessary when using CO2 as a tracer gas in decay and constant emission methods....

  8. Office workers' sick building syndrome and indoor carbon dioxide concentrations.

    Science.gov (United States)

    Tsai, Dai-Hua; Lin, Jia-Shiang; Chan, Chang-Chuan

    2012-01-01

    This study attempted to determine whether any association exists between sick building syndrome (SBS) and indoor carbon dioxide (CO(2)) concentrations. We evaluated SBS among 111 office workers in August and November 2003. The environmental conditions in the office, including CO(2) concentrations, temperature, relative humidity, and fine particulate matter (PM(2.5)), were continuously monitored. The most prevalent symptoms of the five SBS groups were eye irritation and nonspecific and upper respiratory symptoms. The generalized estimating equation (GEE) models show that workers exposed to indoor CO(2) levels greater than 800 ppm were likely to report more eye irritation or upper respiratory symptoms.

  9. New and future developments in catalysis activation of carbon dioxide

    CERN Document Server

    Suib, Steven L

    2013-01-01

    New and Future Developments in Catalysis is a package of books that compile the latest ideas concerning alternate and renewable energy sources and the role that catalysis plays in converting new renewable feedstock into biofuels and biochemicals. Both homogeneous and heterogeneous catalysts and catalytic processes will be discussed in a unified and comprehensive approach. There will be extensive cross-referencing within all volumes. This volume presents a complete picture of all carbon dioxide (CO2) sources, outlines the environmental concerns regarding CO2, and critica

  10. TIR-1 carbon dioxide laser system for fusion

    Science.gov (United States)

    Adamovich, V. A.; Anisimov, V. N.; Afonin, E. A.; Baranov, V. Iu.; Borzenko, V. L.; Kozochkin, S. M.; Maliuta, D. D.; Satov, Iu. A.; Sebrant, A. Iu.; Smakovski, Iu. B.

    1980-03-01

    The paper examines the TIR-1 carbon dioxide laser system for fusion. The current efforts are concentrated on (1) the microsecond laser pulse plasma heating in solenoids and theta pinches, and (2) nanosecond CO2 laser utilization for inertial confinement fusion. The TIR-1 system was designed to develop nanosecond CO2 laser technology and to study laser-target interaction at 10 microns. This system consists of an oscillator-preamplifier that produces about 1-nsec laser pulse with an energy contrast ratio of 1 million, a large triple-pass amplifier, and a target chamber with diagnostic equipment.

  11. A Review of Carbon Dioxide Selective Membranes: A Topical Report

    Energy Technology Data Exchange (ETDEWEB)

    Dushyant Shekhawat; David R. Luebke; Henry W. Pennline

    2003-12-01

    Carbon dioxide selective membranes provide a viable energy-saving alternative for CO2 separation, since membranes do not require any phase transformation. This review examines various CO2 selective membranes for the separation of CO2 and N2, CO2 and CH4, and CO2 and H2 from flue or fuel gas. This review attempts to summarize recent significant advances reported in the literature about various CO2 selective membranes, their stability, the effect of different parameters on the performance of the membrane, the structure and permeation properties relationships, and the transport mechanism applied in different CO2 selective membranes.

  12. Carbon dioxide stripping in aquaculture -- part III: model verification

    Science.gov (United States)

    Colt, John; Watten, Barnaby; Pfeiffer, Tim

    2012-01-01

    Based on conventional mass transfer models developed for oxygen, the use of the non-linear ASCE method, 2-point method, and one parameter linear-regression method were evaluated for carbon dioxide stripping data. For values of KLaCO2 enrichment remains to be determined. The one-parameter linear regression model was used to vary the C*CO2 over the test, but it did not result in a better fit to the experimental data when compared to the ASCE or fixed C*CO2 assumptions.

  13. Supercritical carbon dioxide: the art of technology in art conservation

    Directory of Open Access Journals (Sweden)

    Ana Aguiar-Ricardo

    2007-01-01

    Full Text Available Herein we present a survey of reported work covering specific applications of liquid and supercritical carbon dioxide (scCO2 in art conservation. CO2 has been tested and applied in a wide range of materials, as well as in various steps of a conservation / restoration operation, such as cleaning, protection and consolidation, and it has been demonstrated that CO2 has a great potential in replacing current conventional conservation processes. In this paper we will present some of the main results published in literature, concerning CO2 applications for the conservation and restoration of paper, wood, waterlogged, ethnographic materials, stone and textiles.

  14. Fractional Carbon Dioxide Laser in Treatment of Acne Scars

    OpenAIRE

    Andrej Petrov; Vesna Pljakovska

    2015-01-01

    BACKGROUND: Scars appear as a result of skin damage during the process of the skin healing. There are two types of acne scars, depending on whether there is a loss or accumulation of collagen: atrophic and hypertrophic. In 80-90% it comes to scars with loss of collagen compared to smaller number of hypertrophic scars and keloids. AIM: The aim of the study was to determine efficiency and safety of fractional carbon dioxide laser in the treatment of acne scars. MATERIAL AND METHODS: The...

  15. Synthesis and characterization of zwitterionic carbon dioxide fixing reagents

    DEFF Research Database (Denmark)

    Mikkelsen, Mette; Jørgensen, Mikkel; Krebs, Frederik C

    2010-01-01

    The synthesis of three amine-based carbon dioxide fixing reagents is presented. The reagents were designed so that they would be able to bind CO2 reversibly through the formation of the well known carbamates that was stabilized through forming a zwitterion. CO2 fixing experiments were performed...... with 13CO2 labeling and medium pressure NMR. The experiments showed that two of the three reagents were able to form carbamates and thus bind CO2. In addition we investigated this particular class of molecules for the possible formation of neutrally charged spiro compounds and we show that these did...

  16. Extraction of bixin from annatto seeds using supercritical carbon dioxide

    OpenAIRE

    Silva,G. F.; Gamarra,Felix M. C.; Oliveira,A. L.; Cabral,F. A.

    2008-01-01

    The solubility of 93% pure bixin in supercritical carbon dioxide (SC-CO2) and of the bixin present in annatto seeds (Bixa orellana L.) was measured. For the seeds, the measurements were made in a temperature range from 30 to 50ºC and pressure between 10 and 35 MPa and for the pure bixin, at 40ºC from 10 to 35 MPa. The main pigments of annatto seeds are bixin and norbixin, but the extracts only showed the presence of cis and trans-bixin, indicating that norbixin is not soluble in SC-CO2. The a...

  17. Effects of tropospheric ozone on methane and carbon dioxide fluxes from peatland mesocosms

    Science.gov (United States)

    Toet, Sylvia; Oliver, Vikki; Helgason, Thorunn; Peacock, Simon; Barnes, Jeremy; Ineson, Phil; Ashmore, Mike

    2010-05-01

    Tropospheric ozone is currently the third most important greenhouse gas, and also the most important gaseous air pollutant globally in terms of effects on vegetation world-wide. At present levels it poses a significant threat to crop yield and forest productivity of sensitive species, while background ozone concentrations are expected to increase further during the next decades. The potential importance of ozone in reducing carbon assimilation, and consequently in increasing atmospheric carbon dioxide concentrations, has been recognised. However, regional modelling studies are based on the impact of ozone on photosynthetic rates and above-ground growth, and do not consider effects of ozone on belowground carbon fluxes. The limited experimental data on the long-term effects of ozone on belowground carbon processes, mainly from arable crop and forest systems, are a major constraint to understanding the impacts of ozone on global carbon fluxes. Very little attention has been paid to ozone effects on peatland carbon dynamics, though northern peatlands store a third of the global soil organic carbon pool and are an important source of atmospheric methane. The aims of this study were to assess the long-term effects of elevated ozone on carbon dioxide and methane fluxes in temperate peatland mesocosms and to identify underlying plant, soil and microbial processes. Mesocosms from a wet heath (Isle of Skye, UK) with vegetation dominated by the peat moss Sphagnum papillosum and the sedge Schoenus nigricans have been exposed to ambient (control) and three elevated levels of ozone in open-top chambers from May 2008. Methane emission, carbon dioxide fluxes and relevant plant and soil variables were measured every 6 weeks (growing season) or 8 weeks (winter). Methane emissions were significantly reduced by elevated ozone over the first 18 months of the experiment. Ecosystem respiration only showed a significant increase in response to ozone in the second growing season, while

  18. Game Changing Development Program - Next Generation Life Support Project: Oxygen Recovery From Carbon Dioxide Using Ion Exchange Membrane Electrolysis Technology

    Science.gov (United States)

    Burke, Kenneth A.; Jiao, Feng

    2016-01-01

    This report summarizes the Phase I research and development work performed during the March 13, 2015 to July 13, 2016 period. The proposal for this work was submitted in response to NASA Research Announcement NNH14ZOA001N, "Space Technology Research, Development, Demonstration, and Infusion 2014 (SpaceTech-REDDI-2014)," Appendix 14GCD-C2 "Game Changing Development Program, Advanced Oxygen Recovery for Spacecraft Life Support Systems Appendix" The Task Agreement for this Phase I work is Document Control Number: GCDP-02-TA-15015. The objective of the Phase I project was to demonstrate in laboratories two Engineering Development Units (EDU) that perform critical functions of the low temperature carbon dioxide electrolysis and the catalytic conversion of carbon monoxide into carbon and carbon dioxide. The low temperature carbon dioxide electrolysis EDU was built by the University of Delaware with Dr. Feng Jiao as the principal investigator in charge of this EDU development (under NASA Contract NNC15CA04C). The carbon monoxide catalytic conversion EDU was built by the NASA Glenn Research Center with Kenneth Burke as the principal investigator and overall project leader for the development of both EDUs. Both EDUs were successfully developed and demonstrated the critical functions for each process. The carbon dioxide electrolysis EDU was delivered to the NASA Johnson Space Center and the carbon monoxide catalytic conversion EDU was delivered to the NASA Marshall Spaceflight Center.

  19. Optimizing the Process Parameters for Electrochemical Reduction of Carbon Dioxide

    Science.gov (United States)

    Mudunur, Santosh shekar

    One the major problems of this modern industrialized world is its dependence on fossil fuels for its energy needs. Burning of fossils fuels generates green-house gases which have adverse effects on global climate contributing to global warming. According to Environmental Protection Agency (EPA), carbon dioxide makes up 80 percent of green-house gases emitted in USA. Electrochemical reduction of carbon dioxide is an approach which uses CO2 emissions to produce other useful hydrocarbons which can be used in many ways. In this study, primary focus was on optimizing the operating conditions, determining the better catalyst material, and analyzing the reaction products for the process of electrochemical reduction of carbon dioxide (ERC). Membrane electrode assemblies (MEA's) are developed by air bushing the metal particles with a spray gun on to Nafion-212 which is a solid polymer based electrolyte (SPE), to support the electrodes in the electrochemical reactor gas diffusion layers (GDL) are developed using porous carbon paper. Anode was always made using the same material which is platinum but cathode material was changed as it is the working electrode. The membrane electrode assembly (MEA) is then placed into the electrochemical reactor along with gas diffusion layer (GDL) to assess the performance of the catalyst material by techniques like linear sweep voltammetry and chronoamperometry. Performance of MEA was analyzed at 4 different potentials, 2 different temperatures and for 2 different cathode catalyst materials. The reaction products of the process are analyzed using gas chromatography (GC) which has thermal conductivity detector (TCD) used for detecting hydrogen (H2), carbon monoxide (CO) and flame ionization detector (FID) used for detecting hydrocarbons. The experiments performed at 40° C gave the better results when compared with the experiments performed at ambient temperature. Also results suggested that copper oxide cathode catalyst has better durability

  20. Carbon dioxide adsorption in chemically activated carbon from sewage sludge.

    Science.gov (United States)

    de Andrés, Juan Manuel; Orjales, Luis; Narros, Adolfo; de la Fuente, María del Mar; Encarnación Rodríguez, María

    2013-05-01

    In this work, sewage sludge was used as precursor in the production of activated carbon by means of chemical activation with KOH and NaOH. The sludge-based activated carbons were investigated for their gaseous adsorption characteristics using CO2 as adsorbate. Although both chemicals were effective in the development of the adsorption capacity, the best results were obtained with solid NaOH (SBA(T16)). Adsorption results were modeled according to the Langmuir and Freundlich models, with resulting CO2 adsorption capacities about 56 mg/g. The SBA(T16) was characterized for its surface and pore characteristics using continuous volumetric nitrogen gas adsorption and mercury porosimetry. The results informed about the mesoporous character of the SBA(T16) (average pore diameter of 56.5 angstroms). The Brunauer-Emmett-Teller (BET) surface area of the SBA(T16) was low (179 m2/g) in comparison with a commercial activated carbon (Airpel 10; 1020 m2/g) and was mainly composed of mesopores and macropores. On the other hand, the SBA(T16) adsorption capacity was higher than that of Airpel 10, which can be explained by the formation of basic surface sites in the SBA(T16) where CO2 experienced chemisorption. According to these results, it can be concluded that the use of sewage-sludge-based activated carbons is a promising option for the capture of CO2. Adsorption methods are one of the current ways to reduce CO2 emissions. Taking this into account, sewage-sludge-based activated carbons were produced to study their CO2 adsorption capacity. Specifically, chemical activation with KOH and NaOH of previously pyrolyzed sewage sludge was carried out. The results obtained show that even with a low BET surface area, the adsorption capacity of these materials was comparable to that of a commercial activated carbon. As a consequence, the use of sewage-sludge-based activated carbons is a promising option for the capture of CO2 and an interesting application for this waste.

  1. Sulfur dioxide leaching of spent zinc-carbon-battery scrap

    Science.gov (United States)

    Avraamides, J.; Senanayake, G.; Clegg, R.

    Zinc-carbon batteries, which contain around 20% zinc, 35% manganese oxides and 10% steel, are currently disposed after use as land fill or reprocessed to recover metals or oxides. Crushed material is subjected to magnetic separation followed by hydrometallurgical treatment of the non-magnetic material to recover zinc metal and manganese oxides. The leaching with 2 M sulfuric acid in the presence of hydrogen peroxide recovers 93% Zn and 82% Mn at 25 °C. Alkaline leaching with 6 M NaOH recovers 80% zinc. The present study shows that over 90% zinc and manganese can be leached in 20-30 min at 30 °C using 0.1-1.0 M sulfuric acid in the presence of sulfur dioxide. The iron extraction is sensitive to both acid concentration and sulfur dioxide flow rate. The effect of reagent concentration and particle size on the extraction of zinc, manganese and iron are reported. It is shown that the iron and manganese leaching follow a shrinking core kinetic model due to the formation of insoluble metal salts/oxides on the solid surface. This is supported by (i) the decrease in iron and manganese extraction from synthetic Fe(III)-Mn(IV)-Zn(II) oxide mixtures with increase in acid concentration from 1 M to 2 M, and (ii) the low iron dissolution and re-precipitation of dissolved manganese and zinc during prolonged leaching of battery scrap with low sulfur dioxide.

  2. The Carbon-Nitrogen Balance of the Nodule and Its Regulation under Elevated Carbon Dioxide Concentration

    Directory of Open Access Journals (Sweden)

    Marc Libault

    2014-01-01

    Full Text Available Legumes have developed a unique way to interact with bacteria: in addition to preventing infection from pathogenic bacteria like any other plant, legumes also developed a mutualistic symbiotic relationship with one gender of soil bacteria: rhizobium. This interaction leads to the development of a new root organ, the nodule, where the differentiated bacteria fix for the plant the atmospheric dinitrogen (atmN2. In exchange, the symbiont will benefit from a permanent source of carbon compounds, products of the photosynthesis. The substantial amounts of fixed carbon dioxide dedicated to the symbiont imposed to the plant a tight regulation of the nodulation process to balance carbon and nitrogen incomes and outcomes. Climate change including the increase of the concentration of the atmospheric carbon dioxide is going to modify the rates of plant photosynthesis, the balance between nitrogen and carbon, and, as a consequence, the regulatory mechanisms of the nodulation process. This review focuses on the regulatory mechanisms controlling carbon/nitrogen balances in the context of legume nodulation and discusses how the change in atmospheric carbon dioxide concentration could affect nodulation efficiency.

  3. The carbon-nitrogen balance of the nodule and its regulation under elevated carbon dioxide concentration.

    Science.gov (United States)

    Libault, Marc

    2014-01-01

    Legumes have developed a unique way to interact with bacteria: in addition to preventing infection from pathogenic bacteria like any other plant, legumes also developed a mutualistic symbiotic relationship with one gender of soil bacteria: rhizobium. This interaction leads to the development of a new root organ, the nodule, where the differentiated bacteria fix for the plant the atmospheric dinitrogen (atmN2). In exchange, the symbiont will benefit from a permanent source of carbon compounds, products of the photosynthesis. The substantial amounts of fixed carbon dioxide dedicated to the symbiont imposed to the plant a tight regulation of the nodulation process to balance carbon and nitrogen incomes and outcomes. Climate change including the increase of the concentration of the atmospheric carbon dioxide is going to modify the rates of plant photosynthesis, the balance between nitrogen and carbon, and, as a consequence, the regulatory mechanisms of the nodulation process. This review focuses on the regulatory mechanisms controlling carbon/nitrogen balances in the context of legume nodulation and discusses how the change in atmospheric carbon dioxide concentration could affect nodulation efficiency.

  4. The Carbon-Nitrogen Balance of the Nodule and Its Regulation under Elevated Carbon Dioxide Concentration

    Science.gov (United States)

    2014-01-01

    Legumes have developed a unique way to interact with bacteria: in addition to preventing infection from pathogenic bacteria like any other plant, legumes also developed a mutualistic symbiotic relationship with one gender of soil bacteria: rhizobium. This interaction leads to the development of a new root organ, the nodule, where the differentiated bacteria fix for the plant the atmospheric dinitrogen (atmN2). In exchange, the symbiont will benefit from a permanent source of carbon compounds, products of the photosynthesis. The substantial amounts of fixed carbon dioxide dedicated to the symbiont imposed to the plant a tight regulation of the nodulation process to balance carbon and nitrogen incomes and outcomes. Climate change including the increase of the concentration of the atmospheric carbon dioxide is going to modify the rates of plant photosynthesis, the balance between nitrogen and carbon, and, as a consequence, the regulatory mechanisms of the nodulation process. This review focuses on the regulatory mechanisms controlling carbon/nitrogen balances in the context of legume nodulation and discusses how the change in atmospheric carbon dioxide concentration could affect nodulation efficiency. PMID:24987690

  5. Poly(urethane–carbonate)s from Carbon Dioxide

    KAUST Repository

    Chen, Zuliang

    2017-03-09

    A one-pot, two-step protocol for the direct synthesis of polyurethanes containing few carbonate linkages through polycondensation of diamines, dihalides, and CO2 in the presence of Cs2CO3 and tetrabutylammonium bromide is described. The conditions were optimized by studying the polycondensation of CO2 with 1,6-hexanediamine and 1,4-dibromobutane as model monomers. Then, various diamines and dihalides were tested under optimal conditions. Miscellaneous samples of such carbonate-containing polyurethanes exhibiting molar masses from 6000 to 22 000 g/mol (GPC) and yields higher than 85% were obtained. The thermal properties of such polyurethanes were unveiled by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA): they were found very similar to those of traditional polyurethanes obtained by diisocyanates + diols polycondensation.

  6. Evaluation and Enhancement of Carbon Dioxide Flooding Through Sweep Improvement

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Richard

    2009-09-30

    Carbon dioxide displacement is a common improved recovery method applied to light oil reservoirs (30-45{degrees}API). The economic and technical success of CO{sub 2} floods is often limited by poor sweep efficiency or large CO{sub 2} utilization rates. Projected incremental recoveries for CO{sub 2} floods range from 7% to 20% of the original oil in place; however, actual incremental recoveries range from 9% to 15% of the original oil in place, indicating the potential for significant additional recoveries with improved sweep efficiency. This research program was designed to study the effectiveness of carbon dioxide flooding in a mature reservoir to identify and develop methods and strategies to improve oil recovery in carbon dioxide floods. Specifically, the project has focused on relating laboratory, theoretical and simulation studies to actual field performance in a CO{sub 2} flood in an attempt to understand and mitigate problems of areal and vertical sweep efficiency. In this work the focus has been on evaluating the status of existing swept regions of a mature CO{sub 2} flood and developing procedures to improve the design of proposed floods. The Little Creek Field, Mississippi has been studied through laboratory, theoretical, numerical and simulation studies in an attempt to relate performance predictions to historical reservoir performance to determine sweep efficiency, improve the understanding of the reservoir response to CO{sub 2} injection, and develop scaling methodologies to relate laboratory data and simulation results to predicted reservoir behavior. Existing laboratory information from Little Creek was analyzed and an extensive amount of field data was collected. This was merged with an understanding of previous work at Little Creek to generate a detailed simulation study of two portions of the field – the original pilot area and a currently active part of the field. This work was done to try to relate all of this information to an understanding

  7. Transport Models for Radioactive Carbon Dioxide at RWMC

    Energy Technology Data Exchange (ETDEWEB)

    Hull, Laurence Charles; Hohorst, Frederick August

    2001-12-01

    Radioactive carbon dioxide (formed by oxidation of carbon-14) is a highly mobile, radioactive contaminant released from solid wastes buried at the Subsurface Disposal Area (SDA) at the Radioactive Waste Management Complex (RWMC) at the Idaho National Engineering and Environmental Laboratory (INEEL). Radioactive CO2 is chemically active in the environment, volatile, water soluble, and subject to adsorption on solids. For this reason, its fate must be understood and controlled to meet radiological requirements (protection of the atmosphere, aquifer, vadose zones, plants and animals). In the present work, the migration of carbon-14 as dissolved bicarbonate was studied using miscible displacement experiments in water-saturated columns containing sediments from RWMC. Dissolved carbon-14 was retarded relative to the movement of water by a factor of about 3.6, which translates to a partition coefficient (Kd) of 0.8 ml/g. Two different adsorption sites were identified, with one site possibly having a nonlinear adsorption isotherm. A conservative tracer gas, sulfur hexafluoride, was used to measure the tortuosity of sedimentary material for gaseous diffusion. The tortuosity of the RWMC sediment (Spreading Area B sediment) was determined to be 3.2, which is slightly greater than predicted by the commonly used Millington-Quirk equation. In terms of affecting the migration of carbon-14 to the aquifer, the relative importance of the parameters studied is: (1) natural moisture content of the sediments, (2) sediment tortuosity to gas-phase diffusion, and (3) adsorption onto solid phases.

  8. Product selectivity in plasmonic photocatalysis for carbon dioxide hydrogenation

    Science.gov (United States)

    Zhang, Xiao; Li, Xueqian; Zhang, Du; Su, Neil Qiang; Yang, Weitao; Everitt, Henry O.; Liu, Jie

    2017-01-01

    Photocatalysis has not found widespread industrial adoption, in spite of decades of active research, because the challenges associated with catalyst illumination and turnover outweigh the touted advantages of replacing heat with light. A demonstration that light can control product selectivity in complex chemical reactions could prove to be transformative. Here, we show how the recently demonstrated plasmonic behaviour of rhodium nanoparticles profoundly improves their already excellent catalytic properties by simultaneously reducing the activation energy and selectively producing a desired but kinetically unfavourable product for the important carbon dioxide hydrogenation reaction. Methane is almost exclusively produced when rhodium nanoparticles are mildly illuminated as hot electrons are injected into the anti-bonding orbital of a critical intermediate, while carbon monoxide and methane are equally produced without illumination. The reduced activation energy and super-linear dependence on light intensity cause the unheated photocatalytic methane production rate to exceed the thermocatalytic rate at 350 °C. PMID:28230100

  9. Carbon dioxide capture using resin-wafer electrodeionization

    Science.gov (United States)

    Lin, YuPo J.; Snyder, Seth W.; Trachtenberg, Michael S.; Cowan, Robert M.; Datta, Saurav

    2015-09-08

    The present invention provides a resin-wafer electrodeionization (RW-EDI) apparatus including cathode and anode electrodes separated by a plurality of porous solid ion exchange resin wafers, which when in use are filled with an aqueous fluid. The apparatus includes one or more wafers comprising a basic ion exchange medium, and preferably includes one or more wafers comprising an acidic ion exchange medium. The wafers are separated from one another by ion exchange membranes. The fluid within the acidic and/or basic ion exchange wafers preferably includes, or is in contact with, a carbonic anhydrase (CA) enzyme to facilitate conversion of bicarbonate ion to carbon dioxide within the acidic medium. A pH suitable for exchange of CO.sub.2 is electrochemically maintained within the basic and acidic ion exchange wafers by applying an electric potential across the cathode and anode.

  10. Catalytic conversion of methane: Carbon dioxide reforming and oxidative coupling

    KAUST Repository

    Takanabe, Kazuhiro

    2012-01-01

    Natural gas conversion remains one of the essential technologies for current energy needs. This review focuses on the mechanistic aspects of the development of efficient and durable catalysts for two reactions, carbon dioxide reforming and the oxidative coupling of methane. These two reactions have tremendous technological significance for practical application in industry. An understanding of the fundamental aspects and reaction mechanisms of the catalytic reactions reviewed in this study would support the design of industrial catalysts. CO 2 reforming of methane utilizes CO 2, which is often stored in large quantities, to convert as a reactant. Strategies to eliminate carbon deposition, which is the major problem associated with this reaction, are discussed. The oxidative coupling of methane directly produces ethylene in one reactor through a slightly exothermic reaction, potentially minimizing the capital cost of the natural gas conversion process. The focus of discussion in this review will be on the attainable yield of C 2 products by rigorous kinetic analyses.

  11. Carbonate fuel cell system with integrated carbon dioxide/thermal management

    Energy Technology Data Exchange (ETDEWEB)

    Paetsch, L.

    1995-08-01

    The objective of the present work is to define the stack design and system requirements for a commercial-scale carbonate fuel cell with an integrated carbon dioxide management system. Significant simplification and cost reduction of the system is achieved by direct transfer of the fuel exhaust to the oxidant inlet of the fuel cell, thereby eliminating the anode exhaust converter and high temperature piping utilized in conventional system designs.

  12. Reactions of Vanadocene-Carbyls with Carbon Monoxide, Xylylisocyanide and Carbon Dioxide

    NARCIS (Netherlands)

    Nieman, J.; Teuben, J.H.

    1985-01-01

    Vanadocene-allyl Cp2V(η1-C3H5) (1a) reacts with strong π-acceptor substrate ligands such as carbon monoxide, carbon dioxide and isonitriles. No reactions are observed with poorer π-acceptor substrates such as alkynes and nitriles. Reaction of 1a with CO gives Cp[η4-C5H5(C3H5)]V(CO)2, showing that

  13. Effects of Carbonization Parameters of Moso-Bamboo-Based Porous Charcoal on Capturing Carbon Dioxide

    OpenAIRE

    Pei-Hsing Huang; Jhih-Wei Jhan; Yi-Ming Cheng; Hau-Hsein Cheng

    2014-01-01

    This study experimentally analyzed the carbon dioxide adsorption capacity of Moso-bamboo- (Phyllostachys edulis-) based porous charcoal. The porous charcoal was prepared at various carbonization temperatures and ground into powders with 60, 100, and 170 meshes, respectively. In order to understand the adsorption characteristics of porous charcoal, its fundamental properties, namely, charcoal yield, ash content, pH value, Brunauer-Emmett-Teller (BET) surface area, iodine number, pore volume, a...

  14. Glutamine Synthetases GLN1;2 and GLN2 in Relation to Arabidopsis Growth Response to Elevated Atmospheric Carbon Dioxide and Varying Nitrogen Forms

    DEFF Research Database (Denmark)

    Vurrakula, Swathi

    content while diluting nitrogen concentrations. Such a reduction in nitrogen concentration will affect plant response to stress and seed/grain yield. Glutamine synthetase (GS) is the central nitrogen-assimilatory enzyme, performing primary and secondary nitrogen assimilation, in response to environmental...... in nitrate assimilation. This was the case as the gln2 mutant biomass was highly reduced with an increased supply of nitrate in solo. Nitrate assimilation was impaired in the mutant in parallel with reduced NR activity and activation state (%), leading to reduced glutamine content while glycine accumulated...

  15. Performance of carbon dioxide vent for direct methanol fuel cells

    Science.gov (United States)

    Prakash, Shruti; Kohl, Paul A.

    Direct methanol fuel cells have potentially high energy density if the balance of plant and fuel losses can be kept to a minimum. CO 2 accumulation in the fuel tank can lower the efficiency and performance of closed-tank methanol fuel cells. This report discusses the implementation of a passive CO 2 vent fabricated with poly(1-trimethyl silyl propyne) and 1,6-divinylperfluorohexane. The performance of the membrane as a selective vent for carbon dioxide in the presence of methanol has been studied at various operating conditions. First, the selectivity of the vent membrane improved with temperature. Second, the activation energy for permeation through the polymer membrane corresponded to diffusion controlled transport of CO 2 and sorption controlled transport for methanol vapor. The activation energy for CO 2 transport through the poly(1-trimethyl silyl propyne) and 1,6-divinylperfluorohexane membrane was less than that for a pure poly(1-trimethyl silyl propyne) membrane. Finally, the polymer had a high selectivity for carbon dioxide compared to both liquid and vapor phase methanol.

  16. Experimental performance of carbon dioxide compressor with parallel compression

    Energy Technology Data Exchange (ETDEWEB)

    Bella, Bachir; Kaemmer, Norbert [Emerson Climate Technologies GmbH, Aachen (Germany)

    2011-07-01

    Carbon dioxide (CO2) was proposed in the recent years as a natural fluid to replace the HFCs in refrigeration applications. Its implementation in refrigeration, first in subcritical and recently in transcritical systems is becoming a technology of increasing importance. Trans-critical CO2 system presents lower COP compared to HFCs systems when the ambient temperature is high. Reciprocating compressors with two compression stages having a vapor injection port (VI) have been proposed for parallel compression to improve the efficiency of the system. Many publications have been presented to explain the application advantage but experimental data are lacking to support the theoretical analysis. The work presented here highlight the advantage of the parallel compresion and explains the experimental tests carried-out on a reciprocating prototype with carbon dioxide working with two compression stages (parallel compression) and finally discusses the experimental results. The compressor is a semi-hermetic four cylinders compressor with one compression chamber (cylinder) dedicated to the parallel compression. The tests was performed on hot gas by-pass cycle at -10 C evaporating temperature varying the intermediate and discharge pressures. The experimental result shows the performance at different operating conditions varying the intermediate pressure. It highlights the influence of the intermediate pressure on the efficiency of the compressor and the system. The intermediate pressure influences the volumetric efficiency of the compressor and consequently the COP of the system. Finally, a system efficiency comparison between this configuration and dedicated compressor for parallel compression have been evaluated.

  17. Electrochemical device for converting carbon dioxide to a reaction product

    Science.gov (United States)

    Masel, Richard I.; Chen, Qingmei; Liu, Zengcai; Kutz, Robert

    2016-11-01

    An electrochemical device converts carbon dioxide to a reaction product. The device includes an anode and a cathode, each comprising a quantity of catalyst. The anode and cathode each has reactant introduced thereto. A polymer electrolyte membrane is interposed between the anode and the cathode. At least a portion of the cathode catalyst is directly exposed to gaseous carbon dioxide during electrolysis. The average current density at the membrane is at least 20 mA/cm.sup.2, measured as the area of the cathode gas diffusion layer that is covered by catalyst, and CO selectivity is at least 50% at a cell potential of 3.0 V. In some embodiments, the polymer electrolyte membrane comprises a polymer in which a constituent monomer is (p-vinylbenzyl)-R, where R is selected from the group consisting of imidazoliums, pyridiniums and phosphoniums. In some embodiments, the polymer electrolyte membrane is a Helper Membrane comprising a polymer containing an imidazolium ligand, a pyridinium ligand, or a phosphonium ligand.

  18. Carbon Dioxide Shuttling Thermochemical Storage Using Strontium Carbonate

    Energy Technology Data Exchange (ETDEWEB)

    Mei, Renwei [Univ. of Florida, Gainesville, FL (United States). Dept. of Mechanical and Aerospace Engineering

    2015-06-15

    Phase I concludes with significant progress made towards the SunShot ELEMENTS goals of high energy density, high power density, and high temperature by virtue of a SrO/SrCO3 based material. A detailed exploration of sintering inhibitors has been conducted and relatively stable materials supported by YSZ or SrZO3 have been identified as the leading candidates. In 15 cycle runs using a 3 hour carbonation duration, several materials demonstrated energy densities of roughly 1500 MJ/m3 or greater. The peak power density for the most productive materials consistently exceeded 40 MW/m3—an order of magnitude greater than the SOPO milestone. The team currently has a material demonstrating nearly 1000 MJ/m3 after 100 abbreviated (1 hour carbonation) cycles. A subsequent 8 hour carbonation after the 100 cycle test exhibited over 1500 MJ/m3, which is evidence that the material still has capacity for high storage albeit with slower kinetics. Kinetic carbonation experiments have shown three distinct periods: induction, kinetically-controlled, and finally a diffusion-controlled period. In contrast to thermodynamic equilibrium prediction, higher carbonation temperatures lead to greater conversions over a 1 hour periods, as diffusion of CO2 is more rapid at higher temperatures. A polynomial expression was fit to describe the temperature dependence of the linear kinetically-controlled regime, which does not obey a traditional Arrhenius relationship. Temperature and CO2 partial pressure effects on the induction period were also investigated. The CO2 partial pressure has a strong effect on the reaction progress at high temperatures but is insignificant at temperatures under 900°C. Tomography data for porous SrO/SrCO3 structures at initial stage and after multiple carbonation/decomposition cycles have been obtained. Both 2D slices and 3D reconstructed representations have

  19. Carbon dioxide capture using polyethylenimine-loaded mesoporous carbons.

    Science.gov (United States)

    Wang, Jitong; Chen, Huichao; Zhou, Huanhuan; Liu, Xiaojun; Qiao, Wenming; Long, Donghui; Ling, Licheng

    2013-01-01

    A high efficiency sorbent for CO2 capture was developed by loading polyethylenimine (PEI) on mesoporous carbons which possessed well-developed mesoporous structures and large pore volume. The physicochemical properties of the sorbent were characterized by N2 adsorption/desorption, scanning electron microscopy (SEM), thermal gravimetric analysis (TG) and Fourier transform infrared spectroscopy (FT-IR) techniques followed by testing for CO2 capture. Factors that affected the sorption capacity of the sorbent were studied. The sorbent exhibited extraordinary capture capacity with CO2 concentration ranging from 5% to 80%. The optimal PEI loading was determined to be 65 wt.% with a CO2 sorption capacity of 4.82 mmol-CO2/g-sorbent in 15% CO2/N2 at 75 degrees C, owing to low mass-transfer resistance and a high utilization ratio of the amine compound (63%). Moisture had a promoting effect on the sorption separation of CO2. In addition, the developed sorbent could be regenerated easily at 100 degrees C, and it exhibited excellent regenerability and stability. These results indicate that this PEI-loaded mesoporous carbon sorbent should have a good potential for CO2 capture in the future.

  20. Method of carbon dioxide-free hydrogen production from hydrocarbon decomposition over metal salts

    Energy Technology Data Exchange (ETDEWEB)

    Erlebacher, Jonah; Gaskey, Bernard

    2017-10-03

    A process to decompose methane into carbon (graphitic powder) and hydrogen (H.sub.2 gas) without secondary production of carbon dioxide, employing a cycle in which a secondary chemical is recycled and reused, is disclosed.