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1

Diffusion of air (1); carbon dioxide (2)  

Microsoft Academic Search

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) air; (2) carbon dioxide

J. Winkelmann

2007-01-01

2

Carbon Dioxide Extraction from Air: Is It An Option?  

SciTech Connect

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

Klaus Lackner; Hans-Joachim Ziock; Patrick Grimes

1999-02-01

3

Moisture swing sorbent for carbon dioxide capture from ambient air.  

PubMed

An amine-based anion exchange resin dispersed in a flat sheet of polypropylene was prepared in alkaline forms so that it would capture carbon dioxide from air. The resin, with quaternary ammonium cations attached to the polymer structure and hydroxide or carbonate groups as mobile counterions, absorbs carbon dioxide when dry and releases it when wet. In ambient air, the moist resin dries spontaneously and subsequently absorbs carbon dioxide. This constitutes a moisture induced cycle, which stands in contrast to thermal pressure swing based cycles. This paper aims to determine the isothermal performance of the sorbent during such a moisture swing. Equilibrium experiments show that the absorption and desorption process can be described well by a Langmuir isothermal model. The equilibrium partial pressure of carbon dioxide over the resin at a given loading state can be increased by 2 orders of magnitude by wetting the resin. PMID:21688825

Wang, Tao; Lackner, Klaus S; Wright, Allen

2011-07-06

4

Modeling of carbon dioxide based air-to-air air conditioners  

Microsoft Academic Search

The world-wide agreement to restrict the use of chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) has prompted recent research exploring the possibilities of replacement refrigerants, particularly those occurring naturally in the environment. One such natural refrigerant, carbon dioxide, has been considered for certain refrigeration and air conditioning applications. In order to evaluate the potential performance of a refrigeration cycle based on carbon

Douglas MacArthur Robinson

2000-01-01

5

Equipment for Measuring Air Flow, Air Temperature, Relative Humidity, and Carbon Dioxide in Schools. Technical Bulletin.  

ERIC Educational Resources Information Center

|Information on equipment and techniques that school facility personnel may use to evaluate IAQ conditions are discussed. Focus is placed on the IAQ parameters of air flow, air temperature, relative humidity, as well as carbon dioxide and the equipment used to measure these factors. Reasons for measurement and for when the measurement of these…

Jacobs, Bruce W.

6

Elevated air carbon dioxide concentrations increase dissolved carbon leaching from a cropland soil  

Microsoft Academic Search

Increasing leaching losses of carbon from soils due to accelerated weathering and increasing concentrations of dissolved carbon\\u000a as a result of intensified soil respiration are suspected to provide a negative feedback on rising atmospheric CO2 concentrations. We tested this hypothesis by studying concentrations of dissolved carbon and groundwater recharge at the\\u000a Braunschweig free air carbon dioxide enrichment (FACE) experiment under

Jan Siemens; Andreas Pacholski; Katia Heiduk; Anette Giesemann; Ulrike Schulte; René Dechow; Martin Kaupenjohann; Hans-Joachim Weigel

7

On the Robustness of Air-Sea Flux Estimates of Carbon Dioxide from Ocean Inversions  

Microsoft Academic Search

Inverse methods analogous to those used for atmospheric inversions have been adapted to estimate regional air-sea fluxes of carbon dioxide using ocean interior observations of dissolved inorganic carbon and related tracers and an Ocean General Circulation Model (OGCM). We estimate seperately the preindustrial component and the component due to the anthropogenic perturbation of atmospheric carbon dioxide. Previous sensitivity studies have

S. E. Mikaloff Fletcher; N. P. Gruber; A. Jacobson; S. Doney; S. Dutkiewicz; M. Follows; K. Lindsay; D. Menemenlis; A. Mouchet

2004-01-01

8

Carbon dioxide in the prevention of air embolism during open-heart surgery  

Microsoft Academic Search

The factors which are important in the design and use of apparatus for the effective displacement of air by carbon dioxide from chest cavities are examined. High levels of carbon dioxide can be achieved by flowing carbon dioxide at a total flow rate of 51.\\/min. into the chest cavity through two nozzles of 0·5 to 1·0 cm. diameter. The effect

W. Shang Ng; Michael Rosen

1968-01-01

9

Reconstriction of atmospheric carbon dioxide and isotopic carbon-13 dioxide from air occluded in ice cores from Greenland and Antarctica  

SciTech Connect

Carbon dioxide (CO{sub 2}) dioxide (CO{sub 2}) mixing ratio and isotopic carbon-13 dioxide {delta}{sup 13}CO{sub 2} was measured in the air extracted form ice cores from Greenland (GISP 2, Greenland Ice Sheet Project 2) and from Antarctica (Vostok). The goals are to determine the phasing between temperature and atmospheric CO{sub 2} changes during periods of different climatic conditions and to gain insight into the mechanisms producing the observed CO{sub 2} variations. Experimentally, the dry extraction technique at low temperature for CO{sub 2} was used. The extracted air is then condensed quickly at 35{degrees}K and subsequently released into a cell, where the CO{sub 2} mixing ratio is determined by tunable diode infrared laser spectroscopy on a single vibrational-rotational transition in the 4.3-micrometer ({mu}m) band by measuring the absorbance relative to standards. Three standards are processed identically to samples with every three samples. The experimental uncertainty is {plus_minus}3 parts per million (ppm). {delta}{sup 13}/CO{sub 2} is measured in duplicate by using a dry air extraction technique similar to Etheridge, Pearman, and de Silva on larger samples. CO{sub 2} is separated cryogenically from the extracted air, and {delta}{sup 13}CO{sub 2} is measured by stable isotope ratio mass spectrometry. Severe extraction fractionation is observed. It is controlled and accounted for by admitting standard air samples over the ice; the standard air samples are then processed in the same manner as the extracted air samples are then processed in the same manner as the extracted air samples. The {delta}{sup 13}CO{sub 2} results are corrected for nitrous oxide mass interferences and for gravitational fractionation. The experimental uncertainty is better then {plus_minus}0.1 permil. 5 refs., 3 figs.

Wahlen, M. [Univ. of California, La Jolla, CA (United States)

1994-12-31

10

Temperature VS Carbon Dioxide  

NSDL National Science Digital Library

In this activity, students examine the relationship between carbon dioxide levels and global temperature change by studying a graph of these two variables. They will discover that by using data from ice cores, scientists can determine temperature and carbon dioxide levels in the air as far back as a hundred thousand years in the past. The students try to predict which variable is the independent one and then make a graph of temperature change and carbon dioxide levels. After making their graph, students describe the relationship between temperature and carbon dioxide levels in the atmosphere to determine if their predictions were correct.

11

Methane and carbon dioxide ratio in excreted air for quantification of the methane production from ruminants  

Microsoft Academic Search

This technical note presents a simple, fast, reliable and cheap method to estimate the methane (CH4) production from animals by using the CH4 and carbon dioxide (CO2) concentrations in air near the animals combined with an estimation of the total CO2 production from information on intake of metabolizable energy or heat producing units. By using portable equipment to analyse the

J. Madsen; B. S. Bjerg; T. Hvelplund; M. R. Weisbjerg; P. Lund

2010-01-01

12

Infrared Carbon Dioxide Sensor and its Applications in Automotive Air-Conditioning Systems  

Microsoft Academic Search

In this paper, we present the first carbon dioxide sensor designed for automotive applications. The sensor is based on the spectroscopic measurement principle. It includes a new robust micromachined infrared gas-detector and a corresponding, newly developed ASIC. First application studies show its suitability for automatic vehicle airmanagement systems and for leak detection in R744 air conditioning systems.

M. Arndt; M. Sauer

13

On the causal link between carbon dioxide and air pollution mortality  

Microsoft Academic Search

Greenhouse gases and particle soot have been linked to enhanced sea-level, snowmelt, disease, heat stress, severe weather, and ocean acidification, but the effect of carbon dioxide (CO2) on air pollution mortality has not been examined or quantified. Here, it is shown that increased water vapor and temperatures from higher CO2 separately increase ozone more with higher ozone; thus, global warming

Mark Z. Jacobson

2008-01-01

14

Equation of state of shock-compressed liquids - Carbon dioxide and air  

Microsoft Academic Search

Equation-of-state data were measured for liquid carbon dioxide and air shock-compressed to pressures in the range 28-71 GPa using a two-stage light-gas gun. The experimental methods are described. The data indicate that shock-compressed liquid CO2 decomposes at pressures above 34 GPa. Liquid air dissociates above a comparable shock pressure, as does liquid nitrogen. Theoretical intermolecular potentials are derived for CO2

W. J. Nellis; A. C. Mitchell; F. H. Ree; M. Ross; N. C. Holmes; R. J. Trainor; D. J. Erskine

1991-01-01

15

Equation of state of shock-compressed liquids: Carbon dioxide and air  

Microsoft Academic Search

Equation-of-state data were measured for liquid carbon dioxide and air shock-compressed to pressures in the range 28–71 GPa (280–710 kbar) using a two-stage light-gas gun. The experimental methods are described. The data indicate that shock-compressed liquid CO2 decomposes at pressures above 34 GPa. Liquid air dissociates above a comparable shock pressure, as does liquid nitrogen. Theoretical intermolecular potentials are derived

W. J. Nellis; A. C. Mitchell; F. H. Ree; M. Ross; N. C. Holmes; R. J. Trainor; D. J. Erskine

1991-01-01

16

Carbon dioxide  

NSDL National Science Digital Library

Bubbles are an indicator of a chemical reaction. An indicator is an object, material, or organism that tells you if a specific substance is present. In the sugar test, carbon dioxide gas release is an indicator that yeast is using sugar to grow. The more gas produced, the more sugar a specific substance contains.

Arie Melamed-Katz (None;)

2007-06-19

17

Soil Surface Carbon Dioxide Fluxes and Carbon Dioxide Concentrations in Soil Air  

Microsoft Academic Search

We have been monitoring soil surface CO2 fluxes at three AmeriFlux sites in eastern Nebraska for several years. Recently, we have installed soil CO2 sensors at the rainfed soybean site in order to obtain profiles of CO2 concentrations in soil air (to 0.8 m depth). Supporting data include profiles of soil water content and soil temperature, aboveground biomass, leaf area

T. J. Arkebauer; D. Billesbach

2006-01-01

18

Carbon dioxide partial pressure and carbon fluxes of air-water interface in Taihu Lake, China  

NASA Astrophysics Data System (ADS)

To obtain carbon dioxide (CO2) flux between water-air interface of Taihu lake, monthly water samplers at 14 sites and the local meteorological data of the lake were collected and analyzed in 1998. Carbon dioxide partial pressures (pCO2) at air-water interface in the lake were calculated using alkalinity, pH, ionic strength, active coefficient, and water temperature. The carbon fluxes at different sublakes and areas were estimated by concentration gradient between water and air in consideration of Schmidt numbers of 600 and daily mean windspeed at 10 m above water surface. The results indicated that the mean values of pCO2 in Wuli Lake, Meiliang Bay, hydrophyte area, west littoral zone, riverine mouths, and the open lake areas were 1 807.8±1 071.4 (mean±standard deviation) ?atm (1atm=1.013 25×105Pa), 416.3±217.0 ?atm, 576.5±758.8 ?atm, 304.2±243.5 ?atm, 1 933.6±1 144.7 ?atm, and 448.5±202.6 ?atm, respectively. Maximum and minimum pCO2 values were found in the hypertrophic (4 053.7 ?atm) and the eutrophic (3.2 ?atm) areas. The riverine mouth areas have the maximum fluxes (82.0±62.8 mmol/m2a). But there was no significant difference between eutrophic and mesotrophic areas in pCO2 and the flux of CO2. The hydrophyte area, however, has the minimum (-0.58±12.9 mmol/m2a). In respect to CO2 equilibrium, input of the rivers will obviously influence inorganic carbon distribution in the riverine estuary. For example, the annual mean CO2 flux in Zhihugang River estuary was 19 times of that in Meiliang Bay, although the former is only a part of the latter. The sites in the body of the lake show a clear seasonal cycle with pCO2 higher than atmospheric equilibrium in winter, and much lower than atmospheric in summer due to CO2 consumption by photosynthesis. The CO2 amount of the net annual evasion that enters the atmosphere is 28.42×104 t/a, of which those from the west littoral zone and the open lake account for 53.8% and 36.7%, respectively.

Fan, Chengxin; Hu, Weiping; Ford, Phillip W.; Chen, Yuwei; Qu, Wenchuan; Zhang, Lu

2005-03-01

19

Carbon dioxide insufflation versus air insufflation during endoscopic retrograde cholangiopancreatography: a meta-analysis  

PubMed Central

Background and aims Adequate visualization during endoscopic retrograde cholangiopancreatography (ERCP) procedure requires distention of the bowel lumen, usually insufflated with room air. Patients often complain of abdominal pain post-procedure. The use of carbon dioxide insufflation in colonoscopy has been shownto result in less post-procedure abdominal pain and distension. Recently, it has been reported the use of carbon dioxide (CO2) insufflation during ERCP procedure is similarly helpful. The purpose of this study was to evaluate the efficiency, safety and comfort of ERCP involving carbon dioxide insufflation through a meta-analysis of published randomized control trials. Methods Databases including PubMed, EMBASE, the Cochrane Library, the Science Citation Index and momentous meeting abstracts were searched and evaluated by two reviewers independently. Results Five randomized control trials involving 446 patients were analyzed. Meta-analysis showed that patientsin the CO2 insufflation group had lower pain score (VAS) at 1-hour [MD ?12.37, 95%CI(?20.96,?3.78)], 3-hours [MD ?9.81, 95%CI (?17.05, ?2.57)) and 6-hours [MD ?8.78, 95%CI (?13.71, ?3.85)] compared with air insufflation group after procedure. However, there were no significant differences between the two groups regardingtotal procedure time and procedure complication. Conclusions Insufflation with carbon dioxide during ERCP may decrease post-procedure abdominal discomfort without any additional adverse reactions. Thus, CO2 insufflation seems appropriate to use during ERCP procedure. Large trials are required to prove any additional advantages to carbon dioxide insufflation during ERCP.

Wu, Jun

2013-01-01

20

Patient-Controlled Room Air Insufflation Versus Automated Carbon Dioxide Delivery for CT Colonography  

Microsoft Academic Search

OBJECTIVE. Our objective was to prospectively compare colonic distention and patient comfort at screening CT colonography (CTC) with patient-controlled room air (RA) insuffla- tion versus automated carbon dioxide (CO2) delivery. SUBJECTS AND METHODS. Two hundred eight adults undergoing CTC were ran- domized to RA or CO2 (104 per method). Colonic distention was prospectively assessed by seg- ment using a 4-point

Theodore J. Shinners; Perry J. Pickhardt; Andrew J. Taylor; Debra A. Jones; Cara H. Olsen; Shinners TJ; Taylor AJ; Jones DA; Olsen CH

21

Equation of state of shock-compressed liquids - Carbon dioxide and air  

NASA Astrophysics Data System (ADS)

Equation-of-state data were measured for liquid carbon dioxide and air shock-compressed to pressures in the range 28-71 GPa using a two-stage light-gas gun. The experimental methods are described. The data indicate that shock-compressed liquid CO2 decomposes at pressures above 34 GPa. Liquid air dissociates above a comparable shock pressure, as does liquid nitrogen. Theoretical intermolecular potentials are derived for CO2 from the data. The calculated shock temperature for the onset of CO2 decomposition is 4500 K at a volume of 17 cu cm/mol.

Nellis, W. J.; Mitchell, A. C.; Ree, F. H.; Ross, M.; Holmes, N. C.; Trainor, R. J.; Erskine, D. J.

1991-10-01

22

Equation of state of shock-compressed liquids: Carbon dioxide and air  

SciTech Connect

Equation-of-state data were measured for liquid carbon dioxide and air shock-compressed to pressures in the range 28--71 GPa (280--710 kbar) using a two-stage light-gas gun. The experimental methods are described. The data indicate that shock-compressed liquid CO{sub 2} decomposes at pressures above 34 GPa. Liquid air dissociates above a comparable shock pressure, as does liquid nitrogen. Theoretical intermolecular potentials are derived for CO{sub 2} from the data. The calculated shock temperature for the onset of CO{sub 2} decomposition is 4500 K at a volume of 17 cm{sup 3}/mol.

Nellis, W.J.; Mitchell, A.C.; Ree, F.H.; Ross, M.; Holmes, N.C.; Trainor, R.J.; Erskine, D.J. (Lawrence Livermore National Laboratory, University of California, Livermore, California (USA))

1991-10-01

23

Houston Rural vs. Urban Ozone and Carbon Dioxide Concentrations and Air-Surface Exchange Rates  

NASA Astrophysics Data System (ADS)

The Gulf Coast has a unique and complex interaction of chemical production and meteorological conditions. These factors affect ozone distribution in eastern Texas, particularly Houston. Weather conditions during the sample period were unusually hot and dry, and ozone concentrations were exceptionally high for an extended period. Continuous measurements of ozone and carbon dioxide were taken at four meteorological/flux tower sites in the Houston area from mid-August to early September 2000. Ozone concentration and deposition rates and carbon dioxide fluxes will be examined and compared between the urban and rural settings. The ozone deposition rates will be compared to a two-layer biogeochemical model that has been adapted to predict ozone. This model has been developed primarily as a module for regional air quality models.

Gunter, R. L.; Meyers, T. P.

2002-12-01

24

Brookhaven National Laboratory free-air carbon dioxide enrichment forest prototype -- Interim report  

SciTech Connect

A variety of approaches have been used in fumigation experiments to quantify the effects of increasing atmospheric carbon dioxide concentration ([CO{sub 2}]{sub atm}) on plants. Mot of these approaches, reviewed elsewhere (Allen 1992), entail some type of enclosure or chamber. Chambers provide containment of the CO{sub 2}-enriched air and in this way reduce the amount of CO{sub 2} required for the experiment. At the same time, chambers alter microclimate conditions in a variety of ways so that there is a significant chamber effect on the plants within. Free-air carbon dioxide enrichment (FACE) is an alternative experimental strategy in which CO{sub 2}-enriched air is released into the ambient environment in such a way as to provide effective experimental control over [CO{sub 2}]{sub atm} without causing any change in other environmental variables. Early types of free-air exposure systems were built in the Netherlands and England for exposing vegetation to elevated concentrations of atmospheric trace gases. The FACE Program at Brookhaven National Laboratory (BNL) considered these original ideas in designing the BNL FACE systems. The purpose of the current BNL project in the Duke Forest is to develop a FACE system that can provide adequate control over [CO{sub 2}]{sub atm} in a tall forest setting. This report is a preliminary overview of the data and much remains to be done in the analysis.

Hendrey, G.R.; Lewin, K.F.; Nagy, J.

1994-08-01

25

Soil carbon isotopic composition and soil carbon content in an agroecosystem during six years of Free Air Carbon dioxide Enrichment (FACE)  

Microsoft Academic Search

The Free Air Carbon dioxide Enrichment (FACE) experiment conducted at the Federal Agricultural Research Centre (FAL) in Braunschweig in an arable crop rotation (total duration six years) allowed us to trace carbon (C) input in the soil C pool, as the CO2, used in the experiment to increase the atmospheric CO2 concentration, was depleted in C. Accurate assessment of the

Anette Giesemann; Hans-Joachim Weigel

2008-01-01

26

Carbon Dioxide and Oxygen-Nitrogen Ratios as Factors Affecting Salmon Survival in Air-Supersaturated Water  

Microsoft Academic Search

Juvenile sockeye salmon (Oncorhynchus nerka) were exposed to lethal levels of air-supersaturated water (120 percent, 125 percent, 130 percent total gas saturation) containing different oxygen-nitrogen ratios and different carbon dioxide concentrations. Fish mortality was not significantly different at different carbon dioxide levels (1.7 to 22.0 mg\\/liter CO2) when tested at the same total gas saturation concentrations. Total gas saturation levels

Alan V. Nebeker; Gerald R. Bouck; Donald G. Stevens

1976-01-01

27

Air-sea carbon dioxide exchange in the North Pacific Subtropical Gyre: Impplications for the global carbon budget  

Microsoft Academic Search

The role of the ocean as a sink for anthropogenic carbon dioxide is a subject of intensive investigation and debate. Interest in this process is driven by the need to predict the rate of future increase of atmospheric carbon dioxide and subsequent global climatic change. Although estimates of the magnitude of the oceanic sink for carbon dioxide appear to be

Christopher D. Winn; Fred T. Mackenzie; Christopher J. Carrilo; Christopher L. Sabine; David M. Karl

1994-01-01

28

Air-sea carbon dioxide exchange in the North Pacific Subtropical Gyre: Implications for the Global Carbon Budget  

Microsoft Academic Search

The role of the ocean as a sink for anthropogenic carbon dioxide is a subject of intensive investigation and debate. Interest in this process is driven by the need to predict the rate of future increase of atmospheric carbon dioxide and subsequent global climatic change. Although estimates of the magnitude of the oceanic sink for carbon dioxide appear to be

Christopher D. Winn; Fred T. Mackenzie; Christopher J. Carrillo; Christopher L. Sabine; David M. Karl

1994-01-01

29

The air pressure effect on the homogeneous nucleation of carbon dioxide by molecular simulation  

Microsoft Academic Search

Vapour–liquid equilibria (VLE) and the influence of an inert carrier gas on homogeneous vapour to liquid nucleation are investigated by molecular simulation for quaternary mixtures of carbon dioxide, nitrogen, oxygen, and argon. Canonical ensemble molecular dynamics simulation using the Yasuoka–Matsumoto method is applied to nucleation in supersaturated vapours that contain more carbon dioxide than in the saturated state at the

M. Horsch; Z. Lin; T. Windmann; H. Hasse; J. Vrabec

2011-01-01

30

Moisture-swing sorption for carbon dioxide capture from ambient air: a thermodynamic analysis.  

PubMed

An ideal chemical sorbent for carbon dioxide capture from ambient air (air capture) must have a number of favourable properties, such as environmentally benign behaviour, a high affinity for CO(2) at very low concentration (400 ppm), and a low energy cost for regeneration. The last two properties seem contradictory, especially for sorbents employing thermal swing adsorption. On the other hand, thermodynamic analysis shows that the energy cost of an air capture device need only be slightly larger than that of a flue gas scrubber. The moisture swing separation process studied in this paper provides a novel approach to low cost CO(2) capture from air. The anionic exchange resin sorbent binds CO(2) when dry and releases it when wet. A thermodynamic model with coupled phase and chemical equilibria is developed to study the complex H(2)O-CO(2)-resin system. The moisture swing behaviour is compatible with hydration energies changing with the activity of water on the resin surfaces. This activity is in turn set by the humidity. The rearrangement of hydration water on the resin upon the sorption of a CO(2) molecule is predicted as a function of the humidity and temperature. Using water as fuel to drive the moisture swing enables an economical, large-scale implementation of air capture. By generating CO(2) with low partial pressures, the present technology has implications for in situ CO(2) utilizations which require low pressure CO(2) gas rather than liquid CO(2). PMID:23172123

Wang, Tao; Lackner, Klaus S; Wright, Allen B

2012-11-21

31

Air-sea carbon dioxide exchange in the North Pacific subtropical Gyre: Implications for the global carbon budget  

Microsoft Academic Search

After 20 years of investigation the scientific community has been unable to resolve the magnitudes and direction of carbon dioxide fluxes involving oceans and terrestrial biomass. Studies of the authors over the last four years measuring inorganic carbon parameters suggest that the North Pacific Subtropical Cyre (NPSG) is a sink for atmospheric carbon dioxide. This paper presents a mechanism by

Christopher D. Winn; Fred T. Mackenzie; Christopher J. Carrillo; D. M. Karl; C. L. Sabine

1994-01-01

32

Screen for Carbon Dioxide.  

ERIC Educational Resources Information Center

|Presents a set of laboratory experiments that can assist students in the detection of carbon dioxide. Offers a variation of the supported drop method of carbon dioxide detection that provides readily visible positive results. Includes background information on carbon dioxide. (ML)|

Foster, John; And Others

1986-01-01

33

Lubricity effect of carbon dioxide used as an environmentally friendly refrigerant in air-conditioning and refrigeration compressors  

Microsoft Academic Search

Environmental concerns have increased the interest in alternative natural refrigerants for air-conditioning and refrigeration compressors. Carbon dioxide (CO2) or R744 is an attractive candidate to replace harmful hydrofluorocarbon refrigerants, which will need to be replaced in the near future due to their high global warming potential. In this paper the tribological behavior of gray cast iron in the presence of

Emerson Escobar Nunez; Kyriaki Polychronopoulou; Andreas A. Polycarpou

2010-01-01

34

Is the Earth Warming? A Test of the Effect of Increased Carbon Dioxide on the Thermal Properties of Air  

NSDL National Science Digital Library

In this activity, air with increased concentrations of carbon dioxide is produced and the rate of heat loss of that air is compared to today's normal air. This is used to help demonstrate the environmental and economic effects of increased carbon dioxide (CO2) content in the atmosphere. It tests the claim that the Earth's climate is warming due to changes in the relative concentration of gases in the atmosphere. The activity involves students heating and cooling the air in a large glass vessel as a model of the atmosphere. Temperature readings are taken and plotted. This will show the rate of heat loss from "normal" air. Then, the CO2 concentration of the air will be increased and the experiment repeated. The results will demonstrate the effects of increased CO2 on the rate of heat loss from air. Students will then evaluate claims that increasing carbon dioxide will significantly increase the temperature of the atmosphere, and thus lead to climate change, in their lifetime.

Davies, David

35

The air pressure effect on the homogeneous nucleation of carbon dioxide by molecular simulation  

Microsoft Academic Search

Vapour-liquid equilibria (VLE) and the influence of an inert carrier gas on\\u000ahomogeneous vapour to liquid nucleation are investigated by molecular\\u000asimulation for quaternary mixtures of carbon dioxide, nitrogen, oxygen, and\\u000aargon. Canonical ensemble molecular dynamics simulation using the\\u000aYasuoka-Matsumoto method is applied to nucleation in supersaturated vapours\\u000athat contain more carbon dioxide than in the saturated state at the

Martin Horsch; Zengyong Lin; Thorsten Windmann; Hans Hasse; Jadran Vrabec

2010-01-01

36

Soil gas fluxes of N 2 O, CH 4 and CO 2 beneath Lolium perenne under elevated CO 2 : The Swiss free air carbon dioxide enrichment experiment  

Microsoft Academic Search

Fluxes of nitrous oxide, methane and carbon dioxide were measured from soils under ambient (350 µL L-1) and enhanced (600 µL L-1) carbon dioxide partial pressures (pCO2) at the ‘Free Air Carbon Dioxide Enrichment’ (FACE) experiment, Eidgenössische Technische Hochschule (ETH), Eschikon, Switzerland in July 1995, using a GC housed in a mobile laboratory. Measurements were made in plots of Lolium

P. Ineson; P. A. Coward; U. A. Hartwig

1998-01-01

37

Fine root responses of mature deciduous forest trees to free air carbon dioxide enrichment (FACE)  

Microsoft Academic Search

Summary 1. Elevated atmospheric carbon dioxide (CO 2 ) concentrations have often been reported to increase carbon allocation below-ground, particularly to fine root production. However, for trees these responses have primarily been studied in young expanding systems while the evidence for late successional systems that have reached steady state above- and below-ground is very limited. 2. At the Swiss Canopy

Martin Bader; Erika Hiltbrunner; Christian Körner

2009-01-01

38

On the causal link between carbon dioxide and air pollution mortality  

NASA Astrophysics Data System (ADS)

Greenhouse gases and particle soot have been linked to enhanced sea-level, snowmelt, disease, heat stress, severe weather, and ocean acidification, but the effect of carbon dioxide (CO2) on air pollution mortality has not been examined or quantified. Here, it is shown that increased water vapor and temperatures from higher CO2 separately increase ozone more with higher ozone; thus, global warming may exacerbate ozone the most in already-polluted areas. A high-resolution global-regional model then found that CO2 may increase U.S. annual air pollution deaths by about 1000 (350-1800) and cancers by 20-30 per 1 K rise in CO2-induced temperature. About 40% of the additional deaths may be due to ozone and the rest, to particles, which increase due to CO2-enhanced stability, humidity, and biogenic particle mass. An extrapolation by population could render 21,600 (7400-39,000) excess CO2-caused annual pollution deaths worldwide, more than those from CO2-enhanced storminess.

Jacobson, Mark Z.

2008-02-01

39

Indoor air quality assessment of daycare facilities with carbon dioxide, temperature, and humidity as indicators.  

PubMed

Poor indoor air quality (IAQ) in daycare facilities affects both attending children and care providers. Incident rates of upper-respiratory-tract infections have been reported to be higher in children who attend daycare. Excessive carbon dioxide (CO2) exposure can cause several health effects and even sudden infant death. For this study, 26 facilities were randomly selected in a Midwestern county of the United States. CO2, room temperature, and relative humidity were used as indicators for IAQ and comfort levels. These IAQ parameters were continuously monitored for eight hours at each facility by a direct-reading instrument that was calibrated before each measurement. More than 50 percent of the facilities had an average CO2 level over the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) standard of 1,000 parts per million (ppm). For temperature and relative humidity, respectively, 42.3 percent and 15.4 percent of facilities were outside of the ASHRAE-recommended comfort zones. The nap-time average CO2 level was about 117 ppm higher than the non-nap-time level. The increment of the nap-time CO2 level in the sleeping-only room over the level in multipurpose rooms was statistically significant (p < .05). According to stepwise multiple regression analysis, nap-time CO2 level was predicted by CO2 level before occupancy, nap-time average temperature, carbon monoxide, and child density (R2 = .83). It is recommended that an appropriate IAQ standard for daycare facilities be established and that children should not be placed in a completely isolated room during nap time. PMID:12415886

Ferng, Shiaw-Fen; Lee, Li-Wen

2002-11-01

40

Carbon Dioxide Reduction System.  

National Technical Information Service (NTIS)

An automatically operated carbon dioxide reduction system was developed, fabricated and tested. The system was designed to reduce the carbon dioxide equivalent to that produced by one man, and to produce carbon and oxygen. A system such as this is require...

H. Chandler

1964-01-01

41

Separation of root respiration from total soil respiration using carbon-13 labelling during free-air carbon dioxide enrichment (FACE)  

SciTech Connect

Soil respiration constitutes a major component of the global carbon cycle and is likely to be altered by climate change. However, there is an incomplete understanding of the extent to which various processes contribute to total soil respiration, especially the contributions of root and rhizosphere respiration. Here, using a stable carbon isotope tracer, the authors separate the relative contributions of root and soil heterotrophic respiration to total soil respiration in situ. The Free-Air Carbon dioxide Enrichment (FACE) facility in the Duke University Forest (NC) fumigates plots of an undisturbed loblolly pine (Pinus taeda L.) forest with CO{sub 2} that is strongly depleted in {sup 13}C. This labeled CO{sub 2} is found in the soil pore space through live root and mycorrhizal respiration and soil heterotroph respiration of labile root exudates. By measuring the depletion of {sup 13}CO{sub 2} in the soil system, the authors found that the rhizosphere contribution to soil CO{sub 2} reflected the distribution of fine roots in the soil and that late in the growing season roots contributed 55% of total soil respiration at the surface. This estimate may represent an upper limit on the contribution of roots to soil respiration because high atmospheric CO{sub 2} often increases in root density and/or root activity in the soil.

Andrews, J.A.; Harrison, K.G.; Matamala, R.; Schlesinger, W.H.

1999-10-01

42

Soil air carbon dioxide and nitrous oxide concentrations in profiles under tallgrass prairie and cultivation  

SciTech Connect

Assessing the dynamics of gaseous production in soils is of interest because they are important sources and sinks of greenhouse gases. Changes in soil air carbon dioxide (CO{sub 2}) and nitrous oxide (N{sub 2}O) concentrations were studied in a Reading silt loam under prairie and cultivation. Concentrations were measured in situ over a 17-mo period to a depth of 3 m. Multilevel samples permitted collection of gases with subsequent measurement by gas chromatography in the laboratory. Soil air N{sub 2}O concentrations were near atmospheric levels for a majority of the study period in the prairie site but were significantly higher in the cultivated site. Annual mean N{sub 2}O concentrations were 0.403 and 1.09 {micro}L L{sup {minus}1} in the prairie and cultivated sites, respectively. Soil air CO{sub 2} annual mean concentrations were 1.56 {times} 10{sup 4} and 1.10 {times} 10{sup 4} {micro}L L{sup {minus}1} and ranged from 0.096 {times} 10{sup 4} to 6.45 {times} 10{sup 4} {micro}L L{sup {minus}1} and 0.087 {times} 10{sup 4} to 3.59 {times} 10{sup 4} {micro}L L{sup {minus}1} in the prairie and cultivated sites, respectively. Concentrations generally increased with depth, with maximum soil air N{sub 2}O and CO{sub 2} concentrations at 1.0 m in the prairie site and 0.5 m in the cultivated site. Nitrous oxide in the cultivated site and CO{sub 2} at both sites did not change markedly over winter months, but CO{sub 2} and N{sub 2}O concentrations reached maximums during the summer months and decreased as the year progressed. Although soil air concentrations peaked and decreased faster at shallower depths, deeper depths exhibited relative maximum concentrations for longer time periods.

Sotomayor, D. [Univ. of Puerto Rico, Mayagueez (Puerto Rico). Agronomy and Soils Dept.; Rice, C.W. [Kansas State Univ., Manhattan, KS (United States). Dept. of Agronomy

1999-05-01

43

Examination of Mask Disturbance Behavior during a Carbon Dioxide-Enriched Air Challenge  

PubMed Central

Background and Objectives The present investigation examined mask disturbance behavior in the context of a biological challenge. Method Participants included 128 adults (63.3% women; Mage = 23.2, SD = 8.9) who underwent a 10% carbon dioxide-enriched air challenge. Results Mask disturbance behavior, including complete or partial mask removal, was common during the challenge. Moreover, mask removal behavior during the challenge was significantly related to a greater increase in anxiety pre- to post-challenge, as well as greater levels of self-reported avoidance of a future challenge administration. However, mask touching and lifting behaviors were not related to other challenge criterion variables. Limitations The current study consisted primarily of young adults and did not include individuals with a panic disorder diagnosis. Replication and extension of the current findings is recommended. Conclusions Results suggest that mask removal behavior during the challenge may represent a possible behavioral marker of panic-relevant risk, although further work is necessary to determine its usefulness as a challenge measure.

Marshall-Berenz, Erin C.; Gonzalez, Adam; Leyro, Teresa M.; Zvolensky, Michael J.

2011-01-01

44

Carbon dioxide–air mixtures: mass transfer in recycling packed-bed absorption columns operating under high liquid flow rates  

Microsoft Academic Search

The absorption of carbon dioxide–air mixtures in water in a packed-bed recirculating absorption column with an inner diameter of 0.08m and a length of 1.20m was investigated. A model is derived and numerically solved for recycling packed-bed absorption systems in order to determine the overall mass transfer coefficients. The relationship between the KLa values calculated in this work and the

Vural Evren; Tuncay Ça?atay; Ahmet R. Özdural

1999-01-01

45

Role of activated carbon pellets in carbon dioxide removal  

Microsoft Academic Search

The removal of carbon dioxide from gas\\/air streams is more often becoming necessary in many industries for different purposes. In cryogenic air separation plant, air has to be free from carbon dioxide before its liquefaction otherwise blockage due to freezing of heat exchange equipment would result. Enrichment of methane in biogas to have fuel of higher calorific value can be

S. C Sarkar; A Bose

1997-01-01

46

Air-sea carbon dioxide exchange in the North Pacific subtropical Gyre: Implications for the global carbon budget  

SciTech Connect

After 20 years of investigation the scientific community has been unable to resolve the magnitudes and direction of carbon dioxide fluxes involving oceans and terrestrial biomass. Studies of the authors over the last four years measuring inorganic carbon parameters suggest that the North Pacific Subtropical Cyre (NPSG) is a sink for atmospheric carbon dioxide. This paper presents a mechanism by which the NPSG can be a net sink for atmospheric carbon dioxide and the magnitude of this sink is calculated as approximately 0.2 Gt C yr. The authors note that this sink is still approximately an order of magnitude smaller than that needed to balance the global carbon budget. 41 refs., 3 figs., 1 tab.

Winn, C.D.; Mackenzie, F.T.; Carrillo, C.J.; Karl, D.M. (Univ. of Hawaii, Honolulu, HI (United States)); Sabine, C.L. (Princeton Univ., NJ (United States))

1994-06-01

47

Carbon Dioxide Exchange at the Air–Sea Interface: Flux Augmentation by Chemical Reaction  

Microsoft Academic Search

Numerical results for typical ocean conditions indicate that for film thicknesses less than, say, 400tz. oceanic exchange is not influenced by the hydration\\/dehydration reactions of dissolved carbon dioxide. This conclusion is in substantial agreement with the approximate analysis of Bolin [1960]. However, if suitable catalysts are present in the ocean (there is recent evidence to suggest that this may be

J. A. Quinn; N. C. Otto

1971-01-01

48

Development of Models for Carbon Dioxide Reduction Technologies for Spacecraft Air Revitalization.  

National Technical Information Service (NTIS)

Through the respiration process, humans consume oxygen (O2) while producing carbon dioxide (CO2) and water (H2O) as byproducts. For long term space exploration, CO2 concentration in the atmosphere must be managed to prevent hypercapnia. Moreover, CO2 can ...

M. Anderson M. J. Swickrath

2012-01-01

49

Modeling Interactions among Carbon Dioxide, Nitrogen, and Climate on Energy Exchange of Wheat in a Free Air Carbon Dioxide Experiment  

Microsoft Academic Search

upon site conditions. The direction and extent of these changes are important in estimating whether ecosystems Changes in mass and energy exchange by crops under rising atmo- will become more or less water-limited when both Ca spheric CO2 concentration (Ca ) may be affected by N and weather; and air temperatures are rising as hypothesized in cur- Ca interacts with

Robert F. Grant; Bruce A. Kimball; Talbot J. Brooks; Gary W. Wall; Paul J. Pinter; Doug J. Hunsaker; Floyd J. Adamsen; Robert L. Lamorte; Steven W. Leavitt; Thomas L. Thompson; Allan D. Matthias

2001-01-01

50

Production of Carbon Dioxide  

NSDL National Science Digital Library

In this chemistry activity, learners use common chemicals to produce carbon dioxide and observe its properties. This resource includes brief questions for learners to answer after the experiment. Use this activity to introduce learners to carbon dioxide and its use as a fire extinguisher. Note: this activity involves an open flame.

House, The S.

2013-05-15

51

Carbon Dioxide and Climate.  

ERIC Educational Resources Information Center

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

Brewer, Peter G.

1978-01-01

52

Carbon Dioxide Fountain  

ERIC Educational Resources Information Center

|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.)…

Kang, Seong-Joo; Ryu, Eun-Hee

2007-01-01

53

Carioca buoy: Carbon dioxide monitor - multiple-sensor autonomous system monitors carbon dioxide concentration at the ocean sea-air interface  

Microsoft Academic Search

Concentrations of carbon dioxide in the atmosphere are increasing largely because of fossil-fuel combustion, but the rate of increase is only about half of the total emission rate. The balance of the carbon must be taken up in the oceans and the terrestrial biosphere, but the relative importance of each of these sinks - as well as their geographic distribution

L. Merlivat; P. Brault

1995-01-01

54

Measurements of concentrations of chlorofluoromethanes (CFMs) carbon dioxide and carbon isotope ratio in stratospheric and tropospheric air by grab-sampling systems  

Microsoft Academic Search

Measurements of concentrations of chlorofluoromethanes (CFMs), carbon dioxide and carbon isotope ratio in stratospheric and tropospheric air by grab-sampling systems are reported. The balloon-borne grab-sampling system has been launched from Sanriku Balloon Center three times since 1981. It consists of: (1) six sampling cylinders, (2) eight motor driven values, (3) control and monitor circuits, and (4) pressurized housing. Particular consideration

T. Itoh; H. Kubo; H. Honda; T. Tominaga; Y. Makide; A. Yakohata; H. Sakai

1985-01-01

55

Extraction and detection of pesticide residues from air filter inserts using supercritical carbon dioxide  

SciTech Connect

Trace quantities of airborne herbicide residues were collected on adsorbent bed cartridges and were subsequently extracted from the adsorbent using supercritical carbon dioxide. An apparatus was constructed to facilitate the extraction and recovery of the desired analytes. The resulting extracts were analyzed using gas chromatography/mass spectrometry (GC/MS) or high performance liquid chromatography (HPLC) techniques. Results are presented for a series of analytes representative of common commercial pesticides or herbicides.

Zemanian, T.S.; Robins, W.H.; Lee, R.N.; Wright, B.W.

1994-10-01

56

Carbon Dioxide Disposal via Carbonation  

Microsoft Academic Search

Carbonation is a solidification\\/stabilization process. The availability of a carbon dioxide (CO2) fixation technology would serve as insurance in case global warming causes severe restrictions on CO2 emissions. In order to prevent rapid climate change, it will be necessary to stabilize CO2 as carbonate by the carbonation process. Carbonation of the widely occurring mineral olivine (Mg2SiO4) converts CO2 into an

A. Demirbas

2007-01-01

57

Carioca buoy: Carbon dioxide monitor - multiple-sensor autonomous system monitors carbon dioxide concentration at the ocean sea-air interface  

SciTech Connect

Concentrations of carbon dioxide in the atmosphere are increasing largely because of fossil-fuel combustion, but the rate of increase is only about half of the total emission rate. The balance of the carbon must be taken up in the oceans and the terrestrial biosphere, but the relative importance of each of these sinks - as well as their geographic distribution and the uptake mechanisms involved - are still a matter of debate. The rate at which the ocean absorbs carbon dioxide is poorly known. Until now, sensors measuring the concentration of carbon dioxide have been working with the gas phase exclusively by chromatography or infrared analysis. The set of data available today starts to be relatively large and shows that distribution displays a very large time and space variability. Thus, continuous time series measurements made in selected key areas over a long period are necessary. For this purpose an automatic measuring carbon dioxide drifting buoy was developed. The industrial aim of the CARIOCA (carbon interface ocean atmosphere) project is to implement a high accuracy sensor on a drifting buoy in the open sea. This article discusses the technology and specifications of the CARIOCA project.

Merlivat, L. [Universite Paris (France); Brault, P. [SERPE/IESM, Guidel (France)

1995-10-01

58

Eects of breathing air containing 3% carbon dioxide, 35% oxygen or a mixture of 3% carbon dioxide\\/35% oxygen on cerebral and peripheral oxygenation at 150 m and 3459 m  

Microsoft Academic Search

The eects of gas mixtures comprising supplementary 3% carbon dioxide, 35% oxygen or a combination of 3% CO2 plus 35% O2 in ambient air have been compared on arterial blood gases, peripheral and cerebral oxygenation and middle cerebral artery velocity (MCAV) at 150 m and on acute exposure to 3459 m in 12 healthy subjects. Breathing 3% CO2 or 35%

C. H. E. IMRAY; S. WALSH; T. CLARKE; C. TIIVAS; H. HOAR; T. C. HARVEY; C. W. M. CHAN; P. J. G. FORSTER; A. R. BRADWELL; A. D. WRIGHT; Coventry CV

59

Carbon dioxide (reduction).  

National Technical Information Service (NTIS)

The twin problems of global warming, caused by an increase in atmospheric carbon dioxide (CO2) concentrations, and limited fossil fuel resources have stimulated research in the utilization of CO2. These problems would be partially alleviated by the develo...

A. Fujita

2000-01-01

60

Carbon Dioxide Monitoring.  

National Technical Information Service (NTIS)

The collection of luminescent microorganisms are maintained under cultivation to provide suitable biosensors for the testing program for carbon dioxide. The basic bioluminescent agar medium is currently being used for growth of the cultures. Tests of lumi...

P. S. Biernacki J. J. Kalvinskas

1973-01-01

61

Carbon Dioxide Monitoring.  

National Technical Information Service (NTIS)

The program was initiated to establish the feasibility of applying bioluminescent technology for monitoring of carbon dioxide (CO2) in life-support systems for divers, swimmers and underwater habitats. Experiments were performed to obtain bioluminescent c...

P. S. Biernacki J. J. Kalvinskas

1973-01-01

62

Carbon Dioxide Monitoring.  

National Technical Information Service (NTIS)

The program was initiated to establish the feasibility of applying bioluminescent technology for monitoring of carbon dioxide (CO2) in life-support systems for divers, swimmers and underwater habitats. Experiments were performed to obtain bioluminescent c...

P. S. Biernacki J. L. Kalvinskas

1974-01-01

63

Carbon Dioxide Absorption Manifold.  

National Technical Information Service (NTIS)

The device is for removing carbon dioxide from the atmosphere without the attendant release or production of noxious chemicals. It is for use in a submerged submarine. The device includes a housing, inlets, canisters containing lithium hydroxide, a blower...

W. E. McConnaughey

1965-01-01

64

Distributions and air-sea fluxes of carbon dioxide in the Western Arctic Ocean  

NASA Astrophysics Data System (ADS)

The uptake of carbon dioxide (CO2) by the Arctic Ocean is most likely increasing because of the rapid sea-ice retreat that lifted the barriers preventing gas exchange and light penetration for biological growth. Measurements of atmospheric and surface sea water partial pressure of CO2 (pCO2) were conducted during the Chinese National Arctic Research Expedition (CHINARE) cruises from July to September in 2003 and 2008. The latitudinal distribution of pCO2 along the 169°W transect showed a below-atmopsheric pCO2 level in most of the Western Arctic Ocean, with distinct regional differences from Bering Strait northward to the Central Acrctic Ocean. The average air-sea CO2 fluxes on the shelf and slope of the Chukchi Sea were -17.0 and -8.1 mmol m-2 d-1 respectively. In the ice-free zone, the partially ice-covered zone, and the heavily ice-covered zone of the Canada Basin, the fluxes were -4.2, -8.6, -2.5 mmol m-2 d-1 respectively. These rates are lower than other recent estimates. Our new results not only confirmed previous observations that most areas of the Western Arctic Ocean were a CO2 sink in general, but they also revealed that the previously unsampled central basins were a moderate CO2 sink. Analysis of controlling factors in different areas shows that pCO2 in Bering Strait was influenced not only by the Bering inflow waters but also by the high biological production. However, pCO2 fluctuated sharply because of strong water mixing both laterally and vertically. In the marginal ice zone (Chukchi Sea), pCO2 was controlled by ice melt and biological production, both of which would decrease pCO2 onshore of the ice edge. In the nearly ice-free southern Canada Basin, pCO2 increasd latitudinally as a result of atmospheric CO2 uptake due to intensive gas exchange, increased temperature, and decresed biological CO2 uptake due to limited nutrient supply. Finally, pCO2 was moderately lower than the atmospheric value and was relatively stable under the ice sheet of the central Arctic Ocean in very high latitudes. Thus it appears that the Arctic Ocean has a strong potential capacity of absorbing atmospheric CO2 in the future.

Gao, Zhongyong; Chen, Liqi; Sun, Heng; Chen, Baoshan; Cai, Wei-Jun

2012-12-01

65

Carbon dioxide poisoning.  

PubMed

Carbon dioxide is a physiologically important gas, produced by the body as a result of cellular metabolism. It is widely used in the food industry in the carbonation of beverages, in fire extinguishers as an 'inerting' agent and in the chemical industry. Its main mode of action is as an asphyxiant, although it also exerts toxic effects at cellular level. At low concentrations, gaseous carbon dioxide appears to have little toxicological effect. At higher concentrations it leads to an increased respiratory rate, tachycardia, cardiac arrhythmias and impaired consciousness. Concentrations >10% may cause convulsions, coma and death. Solid carbon dioxide may cause burns following direct contact. If it is warmed rapidly, large amounts of carbon dioxide are generated, which can be dangerous, particularly within confined areas. The management of carbon dioxide poisoning requires the immediate removal of the casualty from the toxic environment, the administration of oxygen and appropriate supportive care. In severe cases, assisted ventilation may be required. Dry ice burns are treated similarly to other cryogenic burns, requiring thawing of the tissue and suitable analgesia. Healing may be delayed and surgical intervention may be required in severe cases. PMID:16499405

Langford, Nigel J

2005-01-01

66

Carbon dioxide foam flooding  

Microsoft Academic Search

A method of conducting an enhanced oil recovery process in a subterranean reservoir is described. There is injected into the reservoir as a sweep fluid a foam containing carbon dioxide, water, and a foaming agent having the formula ROCOCHâSOâOM, where R is a straight chain alkyl radical having from 10 to 16 carbon atoms, and M is an alkali metal

P. W. Fischer; L. W. Holm; D. S. Pye

1978-01-01

67

Carbon Dioxide Removal  

NSDL National Science Digital Library

In this experiment using sprigs of Elodea, learners will observe a natural process that removes carbon dioxide (CO2) from Earth's atmosphere. This process is a part of the carbon cycle and results in temperature suitable for life. Note: this experiment requires that learners make observations an hour or the next day after they set up the materials.

History, American M.

2008-01-01

68

A carbon dioxide gas sensor based on solid electrolyte for air quality control  

Microsoft Academic Search

A practical CO2 gas sensor for air quality control is developed by using a combination of a Na3Zr2Si2PO12 (NASICON) as a solid electrolyte and Li2CO3 as a carbonate phase. The sensor's electromotive force (emf) shows a linear relationship with the logarithm of CO2 concentration. Zeolite is chosen as a filter material in order to minimize the effect of interfering gases

K Kaneyasu; K Otsuka; Y Setoguchi; S Sonoda; T Nakahara; I Aso; N Nakagaichi

2000-01-01

69

High accuracy measurements of dry mole fractions of carbon dioxide and methane in humid air  

NASA Astrophysics Data System (ADS)

Traditional techniques for measuring the mole fractions of greenhouse gases in the well-mixed atmosphere have required dry sample gas streams (dew point < -25 °C) to achieve the inter-laboratory compatibility goals set forth by the Global Atmosphere Watch programme of the World Meteorological Organisation (WMO/GAW) for carbon dioxide (±0.1 ppm in the Northern Hemisphere and ±0.05 ppm in the Southern Hemisphere) and methane (±2 ppb). Drying the sample gas to low levels of water vapour can be expensive, time-consuming, and/or problematic, especially at remote sites where access is difficult. Recent advances in optical measurement techniques, in particular cavity ring down spectroscopy, have led to the development of greenhouse gas analysers capable of simultaneous measurements of carbon dioxide, methane and water vapour. Unlike many older technologies, which can suffer from significant uncorrected interference from water vapour, these instruments permit accurate and precise greenhouse gas measurements that can meet the WMO/GAW inter-laboratory compatibility goals (WMO, 2011a) without drying the sample gas. In this paper, we present laboratory methodology for empirically deriving the water vapour correction factors, and we summarise a series of in-situ validation experiments comparing the measurements in humid gas streams to well-characterised dry-gas measurements. By using the manufacturer-supplied correction factors, the dry-mole fraction measurements have been demonstrated to be well within the GAW compatibility goals up to a water vapour concentration of at least 1%. By determining the correction factors for individual instruments once at the start of life, this water vapour concentration range can be extended to at least 2% over the life of the instrument, and if the correction factors are determined periodically over time, the evidence suggests that this range can be extended up to and even above 4% water vapour concentrations.

Rella, C. W.; Chen, H.; Andrews, A. E.; Filges, A.; Gerbig, C.; Hatakka, J.; Karion, A.; Miles, N. L.; Richardson, S. J.; Steinbacher, M.; Sweeney, C.; Wastine, B.; Zellweger, C.

2013-03-01

70

High accuracy measurements of dry mole fractions of carbon dioxide and methane in humid air  

NASA Astrophysics Data System (ADS)

Traditional techniques for measuring the mole fractions of greenhouse gas in the well-mixed atmosphere have required extremely dry sample gas streams (dew point < -25 °C) to achieve the inter-laboratory compatibility goals set forth by the Global Atmospheric Watch program of the World Meteorological Organization (WMO/GAW) for carbon dioxide (±0.1 ppm) and methane (±2 ppb). Drying the sample gas to low levels of water vapor can be expensive, time-consuming, and/or problematic, especially at remote sites where access is difficult. Recent advances in optical measurement techniques, in particular Cavity Ring Down Spectroscopy (CRDS), have led to the development of highly stable and precise greenhouse gas analyzers capable of highly accurate measurements of carbon dioxide, methane, and water vapor. Unlike many older technologies, which can suffer from significant uncorrected interference from water vapor, these instruments permit for the first time accurate and precise greenhouse gas measurements that can meet the WMO/GAW inter-laboratory compatibility goals without drying the sample gas. In this paper, we present laboratory methodology for empirically deriving the water vapor correction factors, and we summarize a series of in-situ validation experiments comparing the measurements in humid gas streams to well-characterized dry-gas measurements. By using the manufacturer-supplied correction factors, the dry-mole fraction measurements have been demonstrated to be well within the GAW compatibility goals up to at least 1% water vapor. By determining the correction factors for individual instruments once at the start of life, this range can be extended to at least 2% over the life of the instrument, and if the correction factors are determined periodically over time, the evidence suggests that this range can be extended above 4%.

Rella, C. W.; Chen, H.; Andrews, A. E.; Filges, A.; Gerbig, C.; Hatakka, J.; Karion, A.; Miles, N. L.; Richardson, S. J.; Steinbacher, M.; Sweeney, C.; Wastine, B.; Zellweger, C.

2012-08-01

71

Aspects of carbon dioxide utilization  

Microsoft Academic Search

Carbon dioxide reacts with hydrogen, alcohols, acetals, epoxides, amines, carbon–carbon unsaturated compounds, etc. in supercritical carbon dioxide or in other solvents in the presence of metal compounds as catalysts. The products of these reactions are formic acid, formic acid esters, formamides, methanol, dimethyl carbonate, alkylene carbonates, carbamic acid esters, lactones, carboxylic acids, polycarbonate (bisphenol-based engineering polymer), aliphatic polycarbonates, etc. Especially,

Iwao Omae

2006-01-01

72

Improved cerebral protection through replacement of residual intracavital air by carbon dioxide: a porcine model using diffusion-weighted magnetic resonance imaging  

Microsoft Academic Search

BackgroundMajor risk of central or peripheral organ damage is attributed to air embolism from incompletely de-aired cardiac chambers after cardiac operations. Replacement of air by carbon dioxide insufflation into the thoracic cavity is widely used. Diffusion-weighted magnetic resonance imaging of the brain detects ischemia within minutes after onset. The reversibility of ischemia in cerebral tissue after massive gaseous emboli has

S Martens; A Theisen; J. O Balzer; M Dietrich; K Graubitz; M Scherer; C Schmitz; M Doss; A Moritz

2004-01-01

73

Carbon dioxide as a feedstock.  

National Technical Information Service (NTIS)

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,...

Creutz Fujita

2000-01-01

74

Air plasma gasification of RDF as a prospective method for reduction of carbon dioxide emission  

NASA Astrophysics Data System (ADS)

Waste disposal dumps are one of sources of carbonic gas penetration in the atmosphere. The waste is treated into RDF (refuse-derived fuel) and used in boilers for electric power or heat generation for decrease in carbonic gas emissions in the atmosphere. In industry power stations on the basis of the combined cycle have the highest efficiency of burning. The paper deals with the application of an air-plasma gasifier using the down draft scheme of RDF transformation into synthesis gas, which afterwards can be used in the combined cycle. Results of calculations of the process characteristics for various RDF compositions are presented. The advantage of the plasma method in comparison with autothermal one is shown. Experimental data are shown.

Bratsev, A. N.; Kumkova, I. I.; Kuznetsov, V. A.; Popov, V. E.; Shtengel', S. V.; Ufimtsev, A. A.

2011-03-01

75

Carbon dioxide absorption methanol process  

Microsoft Academic Search

A process is described for removing carbon dioxide from a feed stream of natural gas, having at least methane, ethane and heavier hydrocarbon, comprising: separating the feed stream in a first separator to form a first stream, having substantially all of the propane and heavier hydrocarbons and carbon dioxide and ethane, and a second stream, having methane, carbon dioxide and

Apffel

1987-01-01

76

Bench Remarks: Carbon Dioxide.  

ERIC Educational Resources Information Center

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

Bent, Henry A.

1987-01-01

77

Carbon dioxide fixation.  

National Technical Information Service (NTIS)

Solar carbon dioxide fixation offers the possibility of a renewable source of chemicals and fuels in the future. Its realization rests on future advances in the efficiency of solar energy collection and development of suitable catalysts for CO(sub 2) conv...

E. Fujita

2000-01-01

78

Aqueous carbon dioxide monitor  

Microsoft Academic Search

This patent describes an apparatus for measuring low levels of carbon dioxide in water sample. It comprises: means for exchanging cations for hydrogen connected to a sample stream; a first membrane separator connected to the cation exchanging means, the first membrane separator having a first and second compartment with the first and second compartments being separated by a membrane, the

1991-01-01

79

Randomized, Controlled Trial of Carbon Dioxide Insufflation During Colonoscopy  

Microsoft Academic Search

INTRODUCTION: Insufflation of air is a cause of discomfort during and after colonoscopy. Although this can be minimized by good technique, the use of carbon dioxide insufflation may provide further benefits. Carbon dioxide is rapidly absorbed and excreted through the lungs. We hypothesized that carbon dioxide would alleviate postcolonoscopy discomfort. METHODS: After they had provided informed consent, patients presenting for

J. Church; C. Delaney

2003-01-01

80

Chemical Extraction of Carbon Dioxide From Air: A Strategy to Avoid Climate Change and Sustain Fossil Energy?  

NASA Astrophysics Data System (ADS)

Fossil energy use has benefited humankind but also threatens our environment. It has increased atmospheric carbon dioxide (CO2) levels from 280 ppm to 370 ppm, over the past century. This rise has been linked to with observed ocean acidification and global warming. Projections indicate that atmospheric CO2 could reach 540 to 970 ppm in 2100, with significant effects on our earth system. Given that fossil fuels are plentiful, cost-effective, and energy rich their use will be limited by our ability to mitigate their environmental impact. Carbon management provides potential solutions to this. Current approaches to manage carbon focus on capturing CO2 from large point sources such as power plants. They are limited because they fail to address emissions from transportation and the myriad of dispersed sources that amount to about half of all emissions. To solve this problem we have proposed and are developing direct CO2 extraction from air as a means to capture emissions from all sources [1-3]. It preserves our fuel distribution and transportation systems, and in principle could allow us to restore CO2 to pre-industrial levels. Our concept utilizes atmospheric circulation to capture CO2 directly from the dilute stream in air (370 ppm) by binding it to an adsorbent. Subsequent heating releases the bound CO2 as a pure stream suitable for permanent sequestration. For example, this cycle is favorable for Ca(OH)2 which reacts rapidly with CO2 to form CaCO3. The heat to recover CO2 from CaCO3 is 190 kJ/mole of C, less than half the heat of combustion of 500 kJ/ mole of C for coal. The scale of CO2 air-extraction plants to offset global emissions is large but could be manageable, and favorable relative to renewable sources. We report experiments on CO2 uptake by alkaline solutions as a function of pH, contact time, and mixing. Both active and passive mixing conditions are explored. Gram scale quantities of CO2 has been extracted from air by Ca(OH)2 and the product CaCO3 analyzed by X ray diffraction and thermal gravimetric analysis. We identify the atmospheric sub-laminar boundary layer and the stagnant liquid surface as potential barriers to CO2 uptake. Strategies to overcome these limits are developed. We discuss other renewable, energy efficient, and effective CO2 scrubbers with lower binding energies. High-resolution simulations are also being performed to characterize the effects of atmospheric mixing, size and geometry of extractors on the collection efficiency. Capture of CO2 from air is a promising long term strategy to sustain fossil energy use by avoiding climate change but much research and development is needed to implement it. [1] Elliott S. et al.,Compensation of atmospheric CO2 buildup through engineered chemical sinkage, Geophys. Res. Lett., 28(7), 1235-1238, 2001. [2] Dubey, M. K. et al., Extraction of carbon dioxide from the atmosphere through engineered chemical sinkage, 2002 American Chemical Society, Division of Fuel Chemistry Preprints, 47(1), 81-84, 2002. [3] Johnston, et al. Chemical Transport Modeling of Potential Atmospheric Carbon Dioxide Sinks, in press Energy Conversion & Management, 2002.

Dubey, M. K.; Ziock, H.; Rueff, G.; Colman, J.; Smith, W. S.

2002-12-01

81

Summer Ice and Carbon Dioxide  

NASA Astrophysics Data System (ADS)

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

Kukla, G.; Gavin, J.

1981-10-01

82

Summer ice and carbon dioxide  

SciTech Connect

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

Kukla, G.; Gavin, J.

1981-10-30

83

Balancing Atmospheric Carbon Dioxide  

Microsoft Academic Search

ABSTRACT Rising carbon dioxide and global temperatures are causing increasingworldwide concern, and pressure towards an internationallaw 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 rainforests, and Caribbean coral reefs suggest that the biological,effects,of climate,change,may,be more,severe,than,climate,models,predict. Efforts to limit

J. Goreau

84

Extraction of semivolatile organic compounds from high-efficiency particulate air (HEPA) filters by supercritical carbon dioxide  

SciTech Connect

Supercritical fluid extraction (SFE) using unmodified carbon dioxide has been explored as an alternative method for the extraction of semivolatile organic compounds from high-efficiency particulate air (HEPA) filters. HEPA filters provide the final stage of containment on many exhaust systems in US Department of Energy (DOE) facilities by preventing the escape of chemical and radioactive materials entrained in the exhausted air. The efficiency of the filters is tested by the manufacturer and DOE using dioctylphthalate (DOP), a substance regulated by the US Environmental Protection Agency under the Resource Conservation and Recovery Act. Therefore, the filters must be analyzed for semivolatile organics before disposal. Ninety-eight acid, base, and neutral semivolatile organics were spiked onto blank HEPA material and extracted using SFE, Soxhlet, automated Soxhlet, and sonication techniques. The SFE conditions were optimized using a Dionex SFE-703 instrument. Average recoveries for the 98 semivolatile compounds are 82.7% for Soxhlet, 74.0% for sonication, 70.2% for SFE, and 62.9% for Soxtec. Supercritical fluid extraction reduces the extraction solvent volume to 10--15 mL, a factor of 20--30 less than Soxhlet and more than 5 times less than Soxtec and sonication. Extraction times of 30--45 min are used compared to 16--18 h for Soxhlet extraction.

Schilling, J.B.

1997-09-01

85

Carbon dioxide absorption methanol process  

Microsoft Academic Search

This patent describes a process for removing carbon dioxide from a feed stream of natural gas having at least methane, ethane and heavier. It comprises: first, separating the feed stream in a first separator to form a first stream having substantially all of the propane and heavier hydrocarbons and carbon dioxide and ethane and a second stream, having methane, carbon

Apffel

1989-01-01

86

THE RESPIRATORY RESPONSE TO CARBON DIOXIDE  

PubMed Central

1. A technique for determining the respiratory response to carbon dioxide on the Peabody principle is described. 2. The relation between minute volume of total pulmonary ventilation and percentage of carbon dioxide in the inspired air can be expressed by a simple mathematical formula, viz. Y = K + abz, in which Y is the ventilation rate, X is the CO2 content of the inspired air, and K, a, and b are constants characteristic for the individual. 3. The respiratory response to carbon dioxide as expressed by the total pulmonary ventilation is slightly greater at high oxygen percentages (90 per cent ±) than at normal oxygen percentages in the inspired air. 4. Respiratory fatigue may consist of two elements—one nervous, manifesting itself in increased excitability of the center and a more marked response when the demand for pulmonary ventilation is small, the other muscular and involving an inability to respond when the demand for pulmonary ventilation is great.

Davies, H. Whitridge; Brow, George R.; Binger, Carl A. L.

1925-01-01

87

SOIL AIR CARBON DIOXIDE CONCENTRATIONS IN A NEW ENGLAND SPRUCE-FIR FORESTS  

EPA Science Inventory

Research and modeling efforts to evaluate soil-soil solution chemical interactions must take into account solution equilibria with soil air CO2. Measurements of soil air CO2 and soil temperature were made in the major horizons of a forest soil in eastern Maine through the 1985 gr...

88

Soil Air Carbon Dioxide Concentrations in a New England Spruce-Fir Forests.  

National Technical Information Service (NTIS)

Research and modeling efforts to evaluate soil-soil solution chemical interactions must take into account solution equilibria with soil air CO2. Measurements of soil air CO2 and soil temperature were made in the major horizons of a forest soil in eastern ...

I. J. Fernandex P. A. Kosian

1987-01-01

89

Air plasma gasification of RDF as a prospective method for reduction of carbon dioxide emission  

Microsoft Academic Search

Waste disposal dumps are one of sources of carbonic gas penetration in the atmosphere. The waste is treated into RDF (refuse-derived fuel) and used in boilers for electric power or heat generation for decrease in carbonic gas emissions in the atmosphere. In industry power stations on the basis of the combined cycle have the highest efficiency of burning. The paper

A. N. Bratsev; I. I. Kumkova; V. A. Kuznetsov; V. E. Popov; S. V. Shtengel; A. A. Ufimtsev

2011-01-01

90

Carbon dioxide and climate  

SciTech Connect

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.

Not Available

1990-10-01

91

Coral reefs and carbon dioxide  

SciTech Connect

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

Buddemeier, R.W. [Kansas Geological Survey, Lawrence, KS (United States)

1996-03-01

92

Effect of Dilution by Nitrogen and\\/or Carbon Dioxide on Methane and Iso-Octane Air Flames  

Microsoft Academic Search

The impact of dilution on laminar burning speed of two different fuels (methane and isooctane) is studied. In the present study, three different diluents are used—nitrogen, carbon dioxide, and a mixture representative of exhaust gases issued from a stoichiometric combustion of methane. Experimental results and PREMIX computations of the CHEMKIN package, using two different kinetic schemes, are presented and compared

F. Halter; F. Foucher; L. Landry; C. Mounaïm-Rousselle

2009-01-01

93

Is Granger causality analysis appropriate to investigate the relationship between atmospheric concentration of carbon dioxide and global surface air temperature?  

NASA Astrophysics Data System (ADS)

Many time series based studies use Granger causality analysis in order to investigate the connection between atmospheric carbon-dioxide concentrations and global mean temperature. This note re-examines the causal relationship between these variables and shows the inappropriateness of the Granger test to the problem under investigation.

Triacca, U.

2005-07-01

94

Heat Transfer Analysis of Air-to-Carbon Dioxide Two-Phase Heat Absorption and Supercritical Heat Rejection  

Microsoft Academic Search

Regulations restricting the present and future use of fluorocarbon-based refrigerants have prompted a worldwide investigation of new refrigerants and refrigeration cycles. In particular, carbon dioxide is a fluid with a history of being used as a refrigerant that has recently been considered for certain applications that may take advantage of its unique thermophysical properties. The high volumetric heat capacity of

Douglas M. Robinson; Eckhard A. Groll

1998-01-01

95

A hybrid process combining oxygen enriched air combustion and membrane separation for post-combustion carbon dioxide capture  

Microsoft Academic Search

For carbon dioxide capture and storage (CCS), similar to a large majority of industrial processes, the separation (i.e. capture) step dominates the costs of the technological chain. Based on a concept of minimal work of concentration, the evaluation of a tentative capture framework which combines an oxygen enrichment step before combustion and a CO2 capture step from flue gas has

Eric Favre; Roda Bounaceur; Denis Roizard

2009-01-01

96

Chemical Extraction of Carbon Dioxide From Air: A Strategy to Avoid Climate Change and Sustain Fossil Energy?  

Microsoft Academic Search

Fossil energy use has benefited humankind but also threatens our environment. It has increased atmospheric carbon dioxide (CO2) levels from 280 ppm to 370 ppm, over the past century. This rise has been linked to with observed ocean acidification and global warming. Projections indicate that atmospheric CO2 could reach 540 to 970 ppm in 2100, with significant effects on our

M. K. Dubey; H. Ziock; G. Rueff; J. Colman; W. S. Smith

2002-01-01

97

Absorption of Carbon Dioxide on Carbonic Anhydrase Containing Substrates.  

National Technical Information Service (NTIS)

Carbonic anhydrase (CA), an enzyme catalyzing carbon dioxide hydration, was evaluated for its enhancement of carbon dioxide removal when it is present in granular materials with high water content during exposure to carbon dioxide in an aerating stream. A...

J. P. Allen

1968-01-01

98

Carbon Dioxide and Ionic Liquid Refrigerants: Compact, Efficient Air Conditioning with Ionic Liquid-Based Refrigerants  

SciTech Connect

BEETIT Project: Notre Dame is developing an air-conditioning system with a new ionic liquid and CO2 as the working fluid. Synthetic refrigerants used in air conditioning and refrigeration systems are potent GHGs and can trap 1,000 times more heat in the atmosphere than CO2 alone—making CO2 an attractive alternative for synthetic refrigerants in cooling systems. However, operating cooling systems with pure CO2 requires prohibitively high pressures and expensive hardware. Notre Dame is creating a new fluid made of CO2 and ionic liquid that enables the use of CO2 at low pressures and requires minimal changes to existing hardware and production lines. This new fluid also produces no harmful emissions and can improve the efficiency of air conditioning systems— enabling new use of CO2 as a refrigerant in cooling systems.

None

2010-10-01

99

Marine Technician's Handbook, Instructions for Taking Air Samples on Board Ship: Carbon Dioxide Project.  

ERIC Educational Resources Information Center

|This booklet is one of a series intended to provide explicit instructions for the collection of oceanographic data and samples at sea. The methods and procedures described have been used by the Scripps Institution of Oceanography and found reliable and up-to-date. Instructions are given for taking air samples on board ship to determine the…

Keeling, Charles D.

100

Evaluation of indoor air quality using the decibel concept based on carbon dioxide and TVOC  

Microsoft Academic Search

Two new units are proposed for the evaluation of indoor air quality using the decibel concept, which give a much better approximation of the human perception of odour intensity, compared to the CO2 and TVOC concentration scales: the decicarbdiox and the decitvoc. On the Psycho-Physical Scale according to Yaglou, the weakest odour that can be detected by the human smell

M. V. Jokl

2000-01-01

101

FREE-AIR CARBON DIOXIDE ENRICHMENT OF SOYBEAN: INFLUENCE OF CROP VARIETY ON RESIDUE DECOMPOSITION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Elevated atmospheric CO2 can result in larger plants returning greater amounts of residues to the soil. However, the effects of elevated CO2 on carbon (C) and nitrogen (N) cycling for different soybean varieties has not been examined. Aboveground residue of eight soybean varieties (Glycine max [L....

102

Carbon dioxide: atmospheric overload  

SciTech Connect

The level of carbon dioxide in the atmosphere is increasing and may double within the next century. The result of this phenomenon, climatic alterations, will adversely affect crop production, water supplies, and global temperatures. Sources of CO2 include the combustion of fossil fuels, photosynthesis, and the decay of organic matter in soils. The most serious effect of possible climatic changes could occur along the boundaries of arid and semiarid regions. Shifts is precipitation patterns could accelerate the processes of desertification. An increase of 5..cap alpha..C in the average temperature of the top 1000 m of ocean water would raise sea level by 2 m. CO2 releases to the atmosphere can be reduced by controlling emissions from fossil fuel-fired facilities and by careful harvesting of forest regions. (3 photos, 5 references)

Not Available

1980-04-01

103

Spectroscopic carbon dioxide sensor for automotive applications  

Microsoft Academic Search

In this paper, we present the first spectroscopic carbon dioxide sensor designed for automotive applications. The sensor is based on the well known infrared measurement principle. It includes a new robust infrared gas-detector and a corresponding, newly developed, ASIC. First application studies show its suitability for automatic vehicle ventilation systems and for leak detection in R744 air conditioning systems.

Michael Arndt; Maximilian Sauer

2004-01-01

104

Carbon Dioxide Emissions and Carbonation Sensors  

Microsoft Academic Search

The gases with higher heat capacities than those of O2 and N2 cause greenhouse effects. Carbon dioxide (CO2) is the main greenhouse gas associated with global climate change. At the present time, coal is responsible for 30–40% of world CO2 emissions from fossil fuels. There was a higher correlation between the amount of carbon dioxide emission and percentage of carbon

A. Demirbas

2007-01-01

105

Pressurized Fuel\\/Air Operated Solid Oxide Fuel Cell Combined Carbon-Dioxide-Capturing High-Performance Power Generation System  

Microsoft Academic Search

The authors recently proposed a solid oxide fuel cell (SOFC) and closed-cycle MHD combined carbon-dioxide-capturing high-performance power generation system using pure oxygen as the oxidant. This combined system can make the best use of the merit of pure oxygen combustion, while its demerit of efficiency deterioration by large required power for oxygen generation still remains. In the present study, the

Yoshitaka Inui; Taichi Ishida; Tomohiro Matsumae

2003-01-01

106

Free-air carbon dioxide enrichment of cotton: Root morphological characteristics  

SciTech Connect

The response of plants to rising global CO{sub 2} concentration is of critical research interest but one neglected aspect is its effect on roots. Root morphological changes in cotton [Gossypium hirsutum (L.)`Delta Pine 77`] were examined in a 2-yr field study. The test crop was grown under two water regimes (wet, 100% of evapotranspiration [ET] replaced and dry, 75% [1990] and 67% [1991] of ET replaced) and two atmospheric CO{sub 2} concentrations (ambient = 370 {mu}mol mol{sup -1} and free-air CO{sub 2} enrichment [FACE] = 550 {mu}mol mol{sup -1}). A FACE technique that allows for CO{sub 2} exposure under field conditions with minimal alteration of plant microclimate was used. Excavated root systems were partitioned into taproot and lateral roots at two growth phases (vegetative and reproductive) Vertical root-pulling resistance was determined at the second sampling; this measure was higher because of CO{sub 2} enrichment but was unaffected by water stress. Water stress affected root variables only at the second sampling; water stress reduced taproot variables more than lateral variables. The larger diameter taproots seen at all sample dates under FACE exhibited large increases in dry weight and volume. FACE often increased lateral root number and lateral dry weights were higher at all sample dates. The development of more robust taproot systems in CO{sub 2}-enriched environments may allow for greater carbohydrate storage for utilization during periods such as boll filling and to ensure root growth for continued exploration of the soil profile to meet nutrient and water demands during peak demand periods. 32 refs., 2 figs., 2 tabs.

Prior, S.A.; Royers, H.H. [National Soil Dynamics Lab., Auburn, AL (United States); Runion, G.B. [Auburn Univ., AL (United States)] [and others

1995-07-01

107

Separation of root respiration from total soil respiration using carbon-13 labelling during free-air carbon dioxide enrichment (FACE)  

Microsoft Academic Search

Soil respiration constitutes a major component of the global carbon cycle and is likely to be altered by climate change. However, there is an incomplete understanding of the extent to which various processes contribute to total soil respiration, especially the contributions of root and rhizosphere respiration. Here, using a stable carbon isotope tracer, the authors separate the relative contributions of

Jeffrey A. Andrews; Kevin G. Harrison; Roser Matamala; William H. Schlesinger

1999-01-01

108

Diffuse volcanic emissions of carbon dioxide from Vulcano Island, Italy  

Microsoft Academic Search

RECENT investigations on Mount Etna (Sicily)1-3 have revealed that volcanoes may release abundant carbon dioxide not only from their active craters, but also from their flanks, as diffuse soil emanations. Here we present analyses of soil gases and air in water wells on Vulcano Island which provide further evidence of such lateral degassing. Nearly pure carbon dioxide, enriched in helium

J. C. Baubron; P. Allard; J. P. Toutain

1990-01-01

109

Physical variation of water vapor, and the relation with carbon dioxide  

Microsoft Academic Search

Analysis of the long term NOAA carbon dioxide flask sample records to examine the exchange among the continental Antarctic air mass and other air masses shows a meteorological variation of carbon dioxide concentration. There is an inverse relation between the seasonal variation of carbon dioxide concentration and water vapor at all stations examined. Well established diffusion coefficients indicate an interaction

W. G. Egan; A. W. Hogan; H. Zhu

1991-01-01

110

Intercomparison of measurements of sulfur dioxide in ambient air by carbonate-impregnated filters and Teco pulsed-fluorescence analyzers  

Microsoft Academic Search

In two previous University of Washington field programs, airborne measurements of SO2 using carbonate-impregnated filters and a Teco pulsed-fluorescence analyzer showed excellent agreement over a range of ambient concentrations from 2 to 127 ppbv. As part of the Gas-Phase Sulfur Intercomparison Experiment (GASIE), ambient air, diluted fivefold to tenfold with zero air, was sampled in the concentration range of 0.02

Ronald J. Ferek; Paul A. Covert; Winston Luke

1997-01-01

111

Magnesite disposal of carbon dioxide  

SciTech Connect

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.

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

1997-08-01

112

Plants Can't Do without Carbon Dioxide.  

ERIC Educational Resources Information Center

Describes an experiment to induce carbon dioxide deficiency to demonstrate its effects on plant growth. Suggests further studies to examine respiration by soil microbes and the effects of relative humidity, other gases, and air pollution on plant growth. (MDH)

Hershey, David R.

1992-01-01

113

Plants Can't Do without Carbon Dioxide.  

ERIC Educational Resources Information Center

|Describes an experiment to induce carbon dioxide deficiency to demonstrate its effects on plant growth. Suggests further studies to examine respiration by soil microbes and the effects of relative humidity, other gases, and air pollution on plant growth. (MDH)|

Hershey, David R.

1992-01-01

114

Net carbon dioxide exchange rates and predicted growth patterns in Alstroemeria Jacqueline' at varying irradiances, carbon dioxide concentrations, and air temperatures  

Microsoft Academic Search

The influence of irradiance, CO[sub 2] concentration, and air temperature on leaf and whole-plant net C exchange rate (NCER) of Alstroemeria Jacqueline' was studied. At ambient CO[sub 2], leaf net photosynthesis was maximum at irradiances above 600 [mu]mol[center dot]m[sup [minus]2][center dot]s[sup [minus]1] photosynthetically active radiation (PAR), while whole-plant NCER required 1,200 [mu]mol[center dot]m[sup [minus]2][center dot]s[sup [minus]1] PAR to be saturated.

E. D. Leonardos; M. J. Tsujita; B. Grodzinski

1994-01-01

115

Carbon dioxide and climate: a bibliography  

Microsoft Academic Search

This bibliography with abstracts presents 394 citations retrieved from the Energy Data Base of the Department of Energy Technical Information Center, Oak Ridge, Tennessee. The citations cover all aspects of the climatic effects of carbon dioxide emissions to the atmosphere. These include carbon cycling, temperature effects, carbon dioxide control technologies, paleoclimatology, carbon dioxide sources and sinks, mathematical models, energy policies,

Ringe

1980-01-01

116

Carbon dioxide and climate. A bibliography  

Microsoft Academic Search

This updated bibliography with abstracts presents 667 citations retrieved from the Energy Data Base of the Department of Energy Technical Information Center, Oak Ridge, Tennessee. The citations cover all aspects of the climatic effects of carbon dioxide emissions to the atmosphere. These include carbon cycling, temperature effects, carbon dioxide control technologies, paleoclimatology, carbon dioxide sources and sinks, mathematical models, energy

Ringe

1981-01-01

117

Carbon Dioxide Information Center thesaurus  

SciTech Connect

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.

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

1986-04-01

118

An alpine treeline in a carbon dioxide-rich world: synthesis of a nine-year free-air carbon dioxide enrichment study.  

PubMed

We evaluated the impacts of elevated CO2 in a treeline ecosystem in the Swiss Alps in a 9-year free-air CO2 enrichment (FACE) study. We present new data and synthesize plant and soil results from the entire experimental period. Light-saturated photosynthesis (A max) of ca. 35-year-old Larix decidua and Pinus uncinata was stimulated by elevated CO2 throughout the experiment. Slight down-regulation of photosynthesis in Pinus was consistent with starch accumulation in needle tissue. Above-ground growth responses differed between tree species, with a 33 % mean annual stimulation in Larix but no response in Pinus. Species-specific CO2 responses also occurred for abundant dwarf shrub species in the understorey, where Vaccinium myrtillus showed a sustained shoot growth enhancement (+11 %) that was not apparent for Vaccinium gaultherioides or Empetrum hermaphroditum. Below ground, CO2 enrichment did not stimulate fine root or mycorrhizal mycelium growth, but increased CO2 effluxes from the soil (+24 %) indicated that enhanced C assimilation was partially offset by greater respiratory losses. The dissolved organic C (DOC) concentration in soil solutions was consistently higher under elevated CO2 (+14 %), suggesting accelerated soil organic matter turnover. CO2 enrichment hardly affected the C-N balance in plants and soil, with unaltered soil total or mineral N concentrations and little impact on plant leaf N concentration or the stable N isotope ratio. Sustained differences in plant species growth responses suggest future shifts in species composition with atmospheric change. Consistently increased C fixation, soil respiration and DOC production over 9 years of CO2 enrichment provide clear evidence for accelerated C cycling with no apparent consequences on the N cycle in this treeline ecosystem. PMID:23340765

Dawes, Melissa A; Hagedorn, Frank; Handa, Ira Tanya; Streit, Kathrin; Ekblad, Alf; Rixen, Christian; Körner, Christian; Hättenschwiler, Stephan

2013-01-23

119

21 CFR 582.1240 - Carbon dioxide.  

Code of Federal Regulations, 2010 CFR

...SUBSTANCES GENERALLY RECOGNIZED AS SAFE General Purpose Food Additives § 582.1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with...

2009-04-01

120

Will peak oil accelerate carbon dioxide emissions?  

Microsoft Academic Search

The relative scarcity of oil suggests that oil production is peaking and will decline thereafter. Some have suggested that this represents an opportunity to reduce carbon dioxide emissions. However, in the absence of constraints on carbon dioxide emission, \\

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

2008-01-01

121

Dust Retardation Studies of Carbon Dioxide Sorbents.  

National Technical Information Service (NTIS)

Surfaces of carbon dioxide sorbent granules were treated with various liquid preparations to diminish dusting tendency and to improve carbon dioxide capacity. Emphasis was placed on a screening program whereby granules of lithium hydroxide were impregnate...

F. Tepper J. V. Friel

1968-01-01

122

Reaction of Calcium Hydroxide with Carbon Dioxide.  

National Technical Information Service (NTIS)

Details for carrying out an experiment on the reaction of calcium hydroxide with carbon dioxide are given. The addition of water is necessary for a reaction between dry calcium hydroxide and carbon dioxide. (ERA citation 02:005491)

F. W. Dorst

1975-01-01

123

Carbon dioxide adsorption on nanomaterials  

NASA Astrophysics Data System (ADS)

In this study, CO2 adsorption in the presence and absence of co-adsorbed H2O was investigated on different nanomaterials including nanocrystalline NaY zeolite (nano NaY), ZnO, MgO and gamma-Al 2O3 nanoparticles as well as mixed phase aluminum nanowhiskers. In the case of nano NaY, FTIR spectra show that a majority of CO2 adsorbs in the pores of these zeolites in a linear complex with the exchangeable cation. Most interesting is the formation of carbonate and bicarbonate on the external surface of nano NaY zeolites, suggesting unique sites for CO 2 adsorption on the surface of these small nanomaterials. Adsorption of 18O-labeled carbon dioxide and theoretical quantum chemical calculations confirms the assignment of these different species. For aluminum oxyhydroxide nanowhiskers and gamma alumina in the absence of co-adsorbed water, CO2 reacts with surface hydroxyl groups to yield adsorbed bicarbonate as well as some carbonate. C18O2 adsorption confirms these assignments. In the case of nanoparticulate ZnO, CO2 adsorption under dry conditions results in formation of carbonate, bicarbonates as well as carboxylates. However, in the presence of co-adsorbed water, only carbonate species is formed. 18O-labeled carbon dioxide adsorption and theoretical quantum chemical calculations confirm the vibrational assignment for these different species. Mixed isotope studies with H2 16O + C18O2 and H2 18O + C16O2 suggest that there is extensive exchange between oxygen in adsorbed water and oxygen atoms in gas-phase carbon dioxide. CO2 adsorption on MgO surfaces, under dry conditions results in formation of carbonate and bicarbonates. Implications for the use of these nanomaterials in carbon dioxide uptake and storage are discussed.

Galhotra, Pragati

124

Carbon Dioxide - Sources and Sinks  

NSDL National Science Digital Library

In this lab activity, students use a chemical indicator (bromothymol blue) to detect the presence of carbon dioxide in animal and plant respiration and in the burning of fossil fuels and its absence in the products of plant photosynthesis. After completing the five parts of this activity, students compare the colors of the chemical indicator in each part and interpret the results in terms of the qualitative importance of carbon sinks and sources.

Universe, Windows T.

125

Aircraft monitoring of surface carbon dioxide exchange  

Microsoft Academic Search

Aircraft-mounted sensors were used to measure the exchange of carbon dioxide above a cornfield, a forest, and a lake under midday conditions. Mean absorption values of 3400, 1200, and 100 milligrams of carbon dioxide per square meter per hour, respectively, are consistent with reported ground-based observations of carbon dioxide flux. Such information, gathered by aircraft, could be used to provide

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

1982-01-01

126

Aircraft Monitoring of Surface Carbon Dioxide Exchange  

Microsoft Academic Search

Aircraft-mounted sensors were used to measure the exchange of carbon dioxide above a cornfield, a forest, and a lake under midday conditions. Mean absorption values of 3400, 1200, and 100 milligrams of carbon dioxide per square meter per hour, respectively, are consistent with reported ground-based observations of carbon dioxide flux. Such information, gathered by aircraft, could be used to provide

R. L. Desjardins; E. J. Brach; P. Alvo; P. H. Schuepp

1982-01-01

127

Modelling Sublimation of Carbon Dioxide  

ERIC Educational Resources Information Center

|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…

Winkel, Brian

2012-01-01

128

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

129

Carbon dioxide and past Antarctic temperature linked  

NASA Astrophysics Data System (ADS)

Antarctic ice core records indicate a strong connection between a rapid rise in temperature and a rapid increase in atmospheric carbon dioxide (CO2) that occurred during the last ice age. Ahn et al. analyzed the carbon dioxide content of air preserved in Antarctic ice cores covering a time period about 37 to 47 thousand years ago, during which Antarctica went through two warming events in the midst of an ice age. The authors show that approximately half of the CO2 increase that occurred during that period happened very quickly, over less than 200 years. Furthermore, this rapid rise in CO2 occurred nearly simultaneously with a rapid rise in Antarctic temperature. Improved knowledge of the past connection between CO2 and climate can help inform understanding of the feedback relationship between CO2 and climate today. (Geophysical Research Letters, doi:10.1029/2012GL053018, 2012)

Balcerak, Ernie

2012-11-01

130

Investigations of the spatial and temporal resolution of retrievals of atmospheric carbon dioxide from the Atmospheric InfraRed Sounder (AIRS).  

NASA Astrophysics Data System (ADS)

As the dominant anthropogenic greenhouse gas, carbon dioxide (CO 2), represents an important component of climate change (IPCC 2007). Owing to burning of fossil fuels and deforestation, atmospheric CO2 concentrations have increased over 110 parts-per-million by volume (ppmv) from 270 ppmv to 380 ppmv since the dawn of the Industrial Revolution. Understanding of the spatial distribution of the sources and sinks of atmospheric CO 2 is necessary not only to predict the future atmospheric abundances but also their effect on future climate. Although designed for deriving high precision temperature and moisture profiles, NASA's Atmospheric InfraRed Sounder (AIRS) IR measurements include broad vertical sensitivity (between 3 and 10 km) to atmospheric CO2 variations. Coupled with AIRS' broad swath pattern and a technique referred to as "cloud-clearing" these measurements enable daily global spatial coverage. Nevertheless, AIRS' ability to determine the spatial distribution of carbon dioxide (CO2) is strongly dependent on its ability to separate the radiative effects of CO2 from temperature not to mention measurement uncertainties due to clouds and other geophysical variables such as moisture and ozone. This research presents a thorough investigation into the temporal and spatial scales that the AIRS can separate temperature (and other geophysical variables) from CO2. Through our detailed understanding of the way satellites view the Earth's atmosphere, we have developed an algorithm capable of retrieving global middle-to-upper tropospheric CO2 concentrations in all-weather conditions with total uncertainties ranging between 1 to 2 ppmv. From a radiative perspective, roughly equivalent to 30 mK to 60 mK, 1 to 2 ppmv, is an awesome feat for a space-borne sensor. Necessary for the remarkable performance of this algorithm, we developed methodologies capable of separating the radiative effect of CO2 variability from temperature, improved the fast rapid transmittance algorithm for AIRS, and derived algorithm diagnostics that provide the case-dependent skill of AIRS algorithms for temperature and all other constituents (e.g. H2O, O3, CO, CH4, and CO2) from theoretical considerations. As a result, the 1 to 2 ppmv uncertainties match extremely well with simulation experiments performed before validation experiments had collected data and the retrieval algorithm was still in its infancy.

Maddy, Eric Sean

131

CARIOCA - monitoring carbon dioxide exchange  

SciTech Connect

Carbon dioxide (CO[sub 2]) gas has been identified as a major contributor to global warming as a so-called [open quotes]greenhouse gas[close quotes]. The ocean acts as the largest sink of atmospheric carbon dioxide, but the calculated values of this effect (2.0 [times] 10[sup 15] grams carbon per annum) are subject to huge inaccuracies of the order of 30 percent. There is a need for data on the geographical distribution of the various sinks and sources of atmospheric carbon dioxide and the variation of the extent of exchange over an annual cycle. Equipment is required that is capable of making measurements over a 12-month period in order to monitor annual variations and spread throughout the world's oceans. The CARIOCA project was set up in order to develop a suitably instrumented drifting buoy. It is a pan-European cooperative effort. This paper describes the sensor and buoy development with particular reference to how the sensors were designed. Preliminary trials have been successfully completed and the overall aim of CARIOCA will be to release a buoyed network of 100 to 150 buoys.

Walton, J. (Chelsea Instruments Ltd., Surry (United Kingdom))

1994-10-01

132

Passive colorimetric dosimeter tubes for ammonia, carbon monoxide, carbon dioxide, hydrogen sulfide, nitrogen dioxide, and sulfur dioxide  

SciTech Connect

Colorimetric, stain length, personal dosimeters operating by gas diffusion have been developed to determine worker exposure for up to an 8-h period for several inorganic airborne contaminants in the range of their threshold limit values. Length of stain, colorimetric dosimeters have been made for the detection of ammonia (NH/sub 3/), carbon monoxide (CO), carbon dioxide (CO/sub 2/), hydrogen sulfide (H/sub 2/S), nitrogen dioxide (NO/sub 2/), and sulfur dioxide (SO/sub 2/) in air. For each gas detection system, the sampler depends on the transfer of the gas by diffusion into a glass tube containing a colorimetric length of stain indicator. The stain length developed in a given period of time is compared to a calibration chart to determine, on the spot, the average gas concentration to which the dosimeter has been exposed. These dosimeters are known by the trade name Vapor Gard.

McKee, E.S.; Pritts, I.M.

1981-08-01

133

Passive colorimetric dosimeter tubes for ammonia, carbon monoxide, carbon dioxide, hydrogen sulfide, nitrogen dioxide and sulfur dioxide  

SciTech Connect

Colorimetric, stain length, personal dosimeters operating by gas diffusion have been developed to determine worker exposure for up to an eight-hour period for several inorganic airborne contaminants in the range of their Threshold Limit Values. Length of stain, colorimetric dosimeters have been made for the detection of ammonia (NH/sub 3/), carbon monoxide (CO), carbon dioxide (CO/sub 2/), hydrogen sulfide (H/sub 2/S), nitrogen dioxide (NO/sub 2/), and sulfur dioxide (SO/sub 2/) in air. For each gas detection system, the sampler depends on the transfer of the gas by diffusion into a glass tube containing a colorimetric length of stain indicator. The stain length developed in a given period of time is compared to a calibration chart to determine, on the spot, the average gas concentration to which the dosimeter has been exposed. These dosimeters are known by the trade name Vapor Gard.

McConnaughey, P.W.; McKee, E.S.; Pritts, I.M.

1985-07-01

134

Carbon dioxide absorption by MEA  

Microsoft Academic Search

Biogas generally contains significant quantities of carbon dioxide in addition to methane. A bubbling column reactor operating\\u000a at atmospheric pressure is proposed for cheap separation and a Mettler RC1 reaction calorimeter was used to build a simplified\\u000a empirical model for measuring the molar heat of solubility of CO2 in aqueous solutions of monoethanolamine (MEA). Determinations were performed in 12 mass%

N. Palmeri; S. Cavallaro; J. C. J. Bart

2008-01-01

135

Lifetime of Excess Atmospheric Carbon Dioxide.  

National Technical Information Service (NTIS)

The authors explore the effects of a changing terrestrial biosphere on the atmospheric residence time of carbon dioxide using three simple ocean carbon cycling models and a model of global terrestrial carbon cycling. We find differences in model behavior ...

B. Moore B. H. Braswell

1994-01-01

136

Management practices affects soil carbon dioxide emission and carbon storage  

Technology Transfer Automated Retrieval System (TEKTRAN)

Agricultural practices contribute about 25% of total anthropogenic carbon dioxide emission, a greenhouse gas responsible for global warming. Soil can act both as sink or source of atmospheric carbon dioxide. Carbon dioxide fixed in plant biomass through photosynthesis can be stored in soil as organi...

137

CORN ROOT INFLUENCE ON AUTOMATED MEASUREMENT OF CARBON DIOXIDE CONCENTRATIONS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Carbon dioxide (CO2) production is a more desirable indicator of soil carbon (C) dynamics than CO2 flux at the soil-air interface, which is significantly influenced by the gas-transport condition of the soil. Production of CO2 can be computed from CO2 concentrations if high-temporal measurements are...

138

Carbon dioxide pneumoperitoneum prevents mortality from sepsis  

Microsoft Academic Search

Background  Carbon dioxide (CO2) pneumoperitoneum has been shown to attenuate the inflammatory response after laparoscopy. This study tested the hypothesis\\u000a that abdominal insufflation with CO2 improves survival in an animal model of sepsis and investigated the associated mechanism.\\u000a \\u000a \\u000a \\u000a Methods  The effect of CO2, helium, and air pneumoperitoneum on mortality was studied by inducing sepsis in 143 rats via intravenous injection of lipopolysaccharide

E. J. Hanly; J. M. Fuentes; A. R. Aurora; S. L. Bachman; A. De Maio; M. R. Marohn; M. A. Talamini

2006-01-01

139

Carbon Dioxide Review: 1982  

NASA Astrophysics Data System (ADS)

A series of publications appeared in 1982 on climatic implications of increases in CO2 concentration. Analyzing the status of numerical modeling of CO2 impact on climate, M. Schlesinger (Oregon State University) has compiled a summary of 66 models, which is, nevertheless, quite inadequate, since Soviet studies as well as some other investigations have not been considered. All these studies show that the recently growing interest in the problem of anthropogenic effects on climate is far from abating, which is quite natural in view of the enormous practical implications of the climate change problem.Since no climatic consequences of CO2 increase have been observed so far, the major way of studying this effect has been numerical simulation of varying complexity, aimed first at an approximate assessment of possible changes in mean global climate (characterized by air surface temperature), and then in zonal and regional climates considered in sophisticated three-dimensional models. Though the estimates of mean global climate warming, on the assumption of a doubled CO2 concentration, vary widely, most of the experts believe that the value 3±1.5°C is most likely. However, this conclusion is inconsistent with the results of studies carried out by R.E. Newell and T.G. Dopplick and by S.B. Idso. Their results show that mean global warming should be about an order of magnitude less. However, their work has been severly criticized and considered erroneous (odd that obviously overestimated values of CO2 warming have not been so radically criticized).

Kondratyev, K. Ya.

140

Carbon dioxide equilibria and their applications  

Microsoft Academic Search

Carbon dioxide, bicarbonate ion, and carbonate ion comprise the most important acid-base system in natural waters, and the equilibria between them regulate the pH of seawater, as well as most rainwater, stream water, river water, and groundwater. Carbon Dioxide Equilibria and Their Applications provides a clear, compact presentation of this topic, which is central to geochemistry and environmental engineering. It

1992-01-01

141

Catalyst Cartridge for Carbon Dioxide Reduction Unit.  

National Technical Information Service (NTIS)

A catalyst cartridge is described for use in a system for the reduction of carbon dioxide to water and carbon, utilizing the Bosch catalytic reaction. A mixture of hydrogen and carbon dioxide gases is compressed, heated to a reaction temperature of 1000 t...

R. F. Holmes

1971-01-01

142

Solubility of Carbon Dioxide in Water.  

ERIC Educational Resources Information Center

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

Bush, Pat; And Others

1992-01-01

143

Capture of green-house carbon dioxide in Portland cement  

SciTech Connect

A novel process has been developed to sequester green-house carbon dioxide produced by the cement industry in precast cement products. Typically, 10--24 wt % of CO{sub 2} produced by calcination of calcium carbonate during clinkering of the cement may be captured. The carbonation process also cures the cement paste within minutes into hard bodies. The process maintains high pH conditions during curing, to allow conventional steel reinforcement of concrete. The process will save time and money to the cement industry, and at the same time, help them to comply with the Clean Air Act by sequestering the green-house carbon dioxide.

Wagh, A.S.; Singh, D.; Pullockaran, J.; Knox, L.

1993-12-31

144

Climate models should include carbon dioxide increases  

NSDL National Science Digital Library

The specific impacts of elevated atmospheric carbon dioxide concentrations during the Australian summer were examined. It was found that plant response to increased carbon dioxide influences atmospheric temperatures and the climate in ways that are not currently captured by climate models. The authors suggest that local and global climate models should include a measure of vegetation response to natural and man-made carbon dioxide increases to accurately account for biospheric feedback.

Al., Narisma E.; Agu

145

Estimated Carbon Dioxide Emissions in 2008: United States  

SciTech Connect

Flow charts depicting carbon dioxide emissions in the United States have been constructed from publicly available data and estimates of state-level energy use patterns. Approximately 5,800 million metric tons of carbon dioxide were emitted throughout the United States for use in power production, residential, commercial, industrial, and transportation applications in 2008. Carbon dioxide is emitted from the use of three major energy resources: natural gas, coal, and petroleum. The flow patterns are represented in a compact 'visual atlas' of 52 state-level (all 50 states, the District of Columbia, and one national) carbon dioxide flow charts representing a comprehensive systems view of national CO{sub 2} emissions. Lawrence Livermore National Lab (LLNL) has published flow charts (also referred to as 'Sankey Diagrams') of important national commodities since the early 1970s. The most widely recognized of these charts is the U.S. energy flow chart (http://flowcharts.llnl.gov). LLNL has also published charts depicting carbon (or carbon dioxide potential) flow and water flow at the national level as well as energy, carbon, and water flows at the international, state, municipal, and organizational (i.e. United States Air Force) level. Flow charts are valuable as single-page references that contain quantitative data about resource, commodity, and byproduct flows in a graphical form that also convey structural information about the system that manages those flows. Data on carbon dioxide emissions from the energy sector are reported on a national level. Because carbon dioxide emissions are not reported for individual states, the carbon dioxide emissions are estimated using published energy use information. Data on energy use is compiled by the U.S. Department of Energy's Energy Information Administration (U.S. EIA) in the State Energy Data System (SEDS). SEDS is updated annually and reports data from 2 years prior to the year of the update. SEDS contains data on primary resource consumption, electricity generation, and energy consumption within each economic sector. Flow charts of state-level energy usage and explanations of the calculations and assumptions utilized can be found at: http://flowcharts.llnl.gov. This information is translated into carbon dioxide emissions using ratios of carbon dioxide emissions to energy use calculated from national carbon dioxide emissions and national energy use quantities for each particular sector. These statistics are reported annually in the U.S. EIA's Annual Energy Review. Data for 2008 (US. EIA, 2010) was updated in August of 2010. This is the first presentation of a comprehensive state-level package of flow charts depicting carbon dioxide emissions for the United States.

Smith, C A; Simon, A J; Belles, R D

2011-04-01

146

Volcanic versus anthropogenic carbon dioxide  

NASA Astrophysics Data System (ADS)

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

Gerlach, Terry

2011-06-01

147

The Carbon Dioxide Greenhouse: Is It Effective?  

NSDL National Science Digital Library

This activity allows students to compare the thermal properties of carbon dioxide with those of air, and can be extended to compare water vapor as well. Students discover that the gas which absorbs the most heat (infrared radiation) is the most effective greenhouse gas because in the atmosphere it would absorb more infrared coming from the surface of the Earth. This activity could be used as either a demonstration or a laboratory activity depending on the availability of equipment. Either a data logger is used to record the changing temperature of air and of carbon dioxide in plastic bottles as they are heated using electric lamps, and then allowed to cool, or if a data logger is not available, then thermometers can be used instead and monitored by students. The site contains teacher notes and instructions with a list of materials and a photograph showing the setup. It also has an introduction for the students and questions for them to answer along with a glossary.

148

Global energy and carbon dioxide  

SciTech Connect

The literature on energy and carbon dioxide (CO/sub 2/) emissions is reviewed and a brief overview of recent work using the IEA/ORAU long-term energy CO/sub 2/ model is given. It was designed to provide forecasts of carbon emissions explicitly based to energy and economic factors. Recent work has focused on developing three emissions scenarios; the extreme scenarios are presented as bracketing the range of likely future emissions rates. Ongoing work will use Monte Carlo techniques to assess uncertainty in future forecasts and attribute uncertainty to uncertainty in model assumptions and parameters. The paper concludes that the model and scenario construction exercises should serve to complement decisionmaking and interaction among scientists and policymakers.

Reilly, J.; Edmonds, J.

1984-08-26

149

Carbon Dioxide Separation Using Thermally Optimized Membranes  

NASA Astrophysics Data System (ADS)

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

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

2002-05-01

150

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

Code of Federal Regulations, 2011 CFR

...false Carbon dioxide, refrigerated liquid. 179.102-1 Section 179.102-1...102-1 Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated liquid must comply with the following...

2011-10-01

151

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

Code of Federal Regulations, 2012 CFR

...false Carbon dioxide, refrigerated liquid. 179.102-1 Section 179.102-1...102-1 Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated liquid must comply with the following...

2012-10-01

152

9 CFR 313.5 - Chemical; carbon dioxide.  

Code of Federal Regulations, 2010 CFR

...LIVESTOCK § 313.5 Chemical; carbon dioxide. The slaughtering of sheep, calves and swine with the use of carbon dioxide gas and the handling in...same principle, are in common use for carbon dioxide anesthesia. They are the...

2009-01-01

153

40 CFR 90.320 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 false Carbon dioxide analyzer calibration...Provisions § 90.320 Carbon dioxide analyzer calibration. (a) Prior to its initial use and monthly thereafter...test, calibrate the NDIR carbon dioxide analyzer as...

2009-07-01

154

9 CFR 313.5 - Chemical; carbon dioxide.  

Code of Federal Regulations, 2010 CFR

...LIVESTOCK § 313.5 Chemical; carbon dioxide. The slaughtering of sheep, calves and swine with the use of carbon dioxide gas and the handling in...same principle, are in common use for carbon dioxide anesthesia. They are the...

2010-01-01

155

40 CFR 90.320 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Carbon dioxide analyzer calibration...Provisions § 90.320 Carbon dioxide analyzer calibration. (a) Prior to its initial use and monthly thereafter...test, calibrate the NDIR carbon dioxide analyzer as...

2010-07-01

156

21 CFR 868.5300 - Carbon dioxide absorbent.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Carbon dioxide absorbent. 868.5300 Section...DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device...

2013-04-01

157

21 CFR 868.1400 - Carbon dioxide gas analyzer.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Carbon dioxide gas analyzer. 868.1400 Section...DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device...

2013-04-01

158

21 CFR 868.5310 - Carbon dioxide absorber.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Carbon dioxide absorber. 868.5310 Section...DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is...

2013-04-01

159

46 CFR 108.431 - Carbon dioxide systems: General.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Carbon dioxide systems: General. 108.431...EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a)...

2010-10-01

160

40 CFR 90.320 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration. 90...Equipment Provisions § 90.320 Carbon dioxide analyzer calibration. ...certification test, calibrate the NDIR carbon dioxide analyzer as follows:...

2013-07-01

161

40 CFR 89.322 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration. 89...Equipment Provisions § 89.322 Carbon dioxide analyzer calibration. ...bi-monthly thereafter, the NDIR carbon dioxide analyzer shall be...

2013-07-01

162

27 CFR 26.222 - Still wines containing carbon dioxide.  

Code of Federal Regulations, 2013 CFR

...false Still wines containing carbon dioxide. 26.222 Section 26.222...222 Still wines containing carbon dioxide. (a) General. Still wines...contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

2013-04-01

163

40 CFR 91.320 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration. 91...Equipment Provisions § 91.320 Carbon dioxide analyzer calibration. ...certification test, calibrate the NDIR carbon dioxide analyzer as follows:...

2013-07-01

164

27 CFR 26.52 - Still wines containing carbon dioxide.  

Code of Federal Regulations, 2013 CFR

...false Still wines containing carbon dioxide. 26.52 Section 26.52...52 Still wines containing carbon dioxide. (a) General. Still wines...contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

2013-04-01

165

SEQUESTERING CARBON DIOXIDE IN COALBEDS  

SciTech Connect

The authors' long term goal is to develop accurate prediction methods for describing the adsorption behavior of gas mixtures on solid adsorbents over complete ranges of temperature, pressure and adsorbent types. The major objectives of the project are to: (1) measure the adsorption behavior of pure CO{sub 2}, methane, nitrogen and their binary and ternary mixtures on several selected coals having different properties at temperatures and pressures applicable to the particular coal being studied, (2) generalize the adsorption results in terms of appropriate properties of the coals, to facilitate estimation of adsorption behavior for coals other than those studied experimentally, (3) delineate the sensitivity of the competitive adsorption of CO{sub 2}, methane and nitrogen to the specific characteristics of the coal on which they are adsorbed; establish the major differences (if any) in the nature of this competitive adsorption on different coals, and (4) test and/or develop theoretically-based mathematical models to represent accurately the adsorption behavior of mixtures of the type for which measurements are made. The specific accomplishments of this project during this reporting period are summarized below in three broad categories outlining experimentation, model development, and coal characterization. (1) Experimental Work: Our adsorption apparatus was reassembled, and all instruments were tested and calibrated. Having confirmed the viability of the experimental apparatus and procedures used, adsorption isotherms for pure methane, carbon dioxide and nitrogen on wet Fruitland coal were measured at 319.3 K (115 F) and pressures to 12.4 MPa (1800 psia). These measurements showed good agreement with our previous data and yielded an expected uncertainty of about 2%. Preparations are underway to measure adsorption isotherms for pure methane, carbon dioxide and nitrogen on two other coals. (2) Model Development: The experimental data were used to evaluate the predictive capabilities of various adsorption models, including the Langmuir/loading ratio correlation, two-dimensional cubic equations of state, and the local density model. In general, all models performed well for Type I adsorption exhibited by methane, nitrogen, and carbon dioxide up to 8.3 MPa (average deviations within 2%). However, for pressures higher than 8.3 MPa (1200 psia), carbon dioxide produced multilayer adsorption behavior similar to Type IV adsorption. Our results to date indicate that the SLD model may be a suitable choice for modeling multilayer coalbed gas adsorption. However, model improvements are required to (a) account for coal heterogeneity and structure complexity, and (b) provide for more accurate density predictions. (3) Coal Characterization: We have identified several well-characterized coals for use in our adsorption studies. The criteria for coal selection has been guided by the need for coals that (a) span the spectrum of properties encountered in coalbed methane production (such as variation in rank), and (b) originate from coalbed methane recovery sites (e.g., San Juan Basin, Black Warrior Basin, etc.). At Pennsylvania State University, we have completed calibrating our instruments using a well-characterized activated carbon. In addition, we have conducted CO{sub 2} and methane uptakes on four samples, including (a) a widely used commercial activated carbon, BPL from Calgon Carbon Corp.; (b) an Illinois No.6 bituminous coal from the Argonne Premium Coal sample bank; (c) a Fruitland Intermediate coal sample; (d) a dry Fruitland sample. The results are as expected, except for a greater sensitivity to the outgassing temperature. ''Standard'' outgassing conditions (e.g., 383.2 K, overnight), which are often used, may not be appropriate for gas storage in coalbeds. Conditions that are more representative of in-situ coal (approximately 313.2 K) may be much more appropriate. In addition, our results highlight the importance of assessing the degree of approach to adsorption equilibrium.

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

2001-06-15

166

Ocean Surface Carbon Dioxide Fugacity from Space  

NASA Astrophysics Data System (ADS)

We have developed a methodology to estimate ocean surface carbon dioxide (CO2) fugacity (partial pressure) using a combination for spacebased parameters, sea surface temperature (AMSR-E), dynamic topography (JASON and OSTM), productivity (MODIS), and salinity (possibly Aquarius) over global oceans. The ocean as the source and sink of CO2 is governed by the ocean-atmosphere exchange of this greenhouse gas. The exchange depends on the difference in fugacity (partial pressure) of carbon dioxide between sea and air, and a transfer velocity. Fugacity in sea is measured largely on ships; they are not sufficient to characterize spatial and temporal variability. Attempts have been made in the past to relate the fugacity in sea to parameters that could be measured from space. These relations are found to be valid only in limited regions and in specific seasons. We have developed a statistical model to estimate the fugacity over global ocean for all seasons from NASA space measurements using the state-of-art statistical techniques. We have produced the fugacity data over global ocean using salinity climatology but will replace the climatology with Aquarius data when they become available. We are evaluating the accuracy of the fugacity data and its application on carbon cycle and will explore proper remedies of any deficiency.

Xie, X.; Liu, W.

2011-12-01

167

CARBON DIOXIDE STORAGE IN PENNSYLVANIA PASTURES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Global warming, caused primarily by the burning of fossil fuels and the resulting increase in atmospheric greenhouse gasses such as carbon dioxide, is increasingly being recognized as a concern for the wellbeing of the planet. Agricultural practices that increase carbon dioxide storage in soil organ...

168

Carbon dioxide: A substitute for phosgene  

Microsoft Academic Search

One of the many goals of the green chemistry movement is to eliminate the use of phosgene (COClâ), an extremely hazardous compound used in many syntheses, including the production of carbamates, organic carbonates, and polymers. One of the most interesting options for eliminating this compound is to replace it with COâ. In addition to carbon dioxide`s abundance and benign nature,

M. Aresta; E. Quaranta

1997-01-01

169

Carbon Dioxide Reduction and Water Electrolysis System.  

National Technical Information Service (NTIS)

An integrated system for oxygen recovery from carbon dioxide was investigated as a breadboard laboratory model of nominal 1/2-man capacity. System design for carbon dioxide reduction was based on alternate operation of two Bosch reactors with periodic coo...

B. C. Kim E. S. Kolic R. H. Cherry J. E. Clifford

1968-01-01

170

Arterialisation of transcutaneous oxygen and carbon dioxide  

Microsoft Academic Search

We compared previously calculated global correction factors for oxygen and carbon dioxide arterial\\/transcutaneous ratios with individual in vivo calibrations from the first arterial sample. In infants beyond the neonatal period and older children in vivo calibration confers little benefit over the use of a global calibration correction factor for transcutaneous carbon dioxide, and may reduce the precision with which arterial

E Broadhurst; P Helms; H Vyas; G Cheriyan

1988-01-01

171

Carbon dioxide in northeastern New Mexico  

Microsoft Academic Search

Carbon dioxide is known to occur in many parts of northeastern New Mexico. The main producing areas include the Bueyeros field in Harding County, Des Moines field in Union County, and Estancia field in Torrance County. In recent years, production has been limited to the Bueyeros field. Wildcat oil tests also have encountered carbon dioxide in Cofax, Mora, and San

ROY W. FOSTER; JAMES G. JENSEN

1972-01-01

172

CARBON DIOXIDE AND OUR OCEAN LEGACY  

Microsoft Academic Search

Global warming is increasing ocean tempera- tures and raising sea levels. New scientific research shows that our oceans are beginning to face yet another threat due to global warm- ing-related emissions - their basic chemistry is changing because of the uptake of carbon dioxide released by human activities. When carbon dioxide is absorbed by the oceans it reacts with seawater

Richard A. Feely; Christopher L. Sabine; Victoria J. Fabry

173

Mercury accumulation in grass and forb species as a function of atmospheric carbon dioxide concentrations and mercury exposures in air and soil.  

PubMed

The goal of this study was to investigate the potential for atmospheric Hg degrees uptake by grassland species as a function of different air and soil Hg exposures, and to specifically test how increasing atmospheric CO(2) concentrations may influence foliar Hg concentrations. Four common tallgrass prairie species were germinated and grown for 7 months in environmentally controlled chambers using two different atmospheric elemental mercury (Hg major; 3.7+/-2.0 and 10.2+/-3.5 ng m(-3)), soil Hg (<0.01 and 0.15+/-0.08 micro g g(-1)), and atmospheric carbon dioxide (CO(2)) (390+/-18, 598+/-22 micro mol mol(-1)) exposures. Species used included two C4 grasses and two C3 forbs. Elevated CO(2) concentrations led to lower foliar Hg concentrations in plants exposed to low (i.e., ambient) air Hg degrees concentrations, but no CO(2) effect was apparent at higher air Hg degrees exposure. The observed CO(2) effect suggests that leaf Hg uptake might be controlled by leaf physiological processes such as stomatal conductance which is typically reduced under elevated CO(2). Foliar tissue exposed to elevated air Hg degrees concentrations had higher concentrations than those exposed to low air Hg degrees , but only when also exposed to elevated CO(2). The relationships for foliar Hg concentrations at different atmospheric CO(2) and Hg degrees exposures indicate that these species may have a limited capacity for Hg storage; at ambient CO(2) concentrations all Hg absorption sites in leaves may have been saturated while at elevated CO(2) when stomatal conductance was reduced saturation may have been reached only at higher concentrations of atmospheric Hg degrees . Foliar Hg concentrations were not correlated to soil Hg exposures, except for one of the four species (Rudbeckia hirta). Higher soil Hg concentrations resulted in high root Hg concentrations and considerably increased the percentage of total plant Hg allocated to roots. The large shifts in Hg allocation patterns-notably under soil conditions only slightly above natural background levels-indicate a potentially strong role of plants in belowground Hg transformation and cycling processes. PMID:16631233

Millhollen, A G; Obrist, D; Gustin, M S

2006-05-02

174

Scaling of Carbon Cycle Processes in a Mountain Ecosystem Using Isotopes of Respired Carbon Dioxide in Nocturnal Cold-air Drainage  

NASA Astrophysics Data System (ADS)

Nocturnal air drainage in mountain ecosystems offers a unique opportunity for scaling of carbon cycle processes in complex terrain using stable isotopes. We have found that more than half of ecosystem-respired CO2 can be transferred advectively from a small (100 ha) watershed at night, and the range of CO2 concentrations in the air collected from a 37 m tower situated at the base of the watershed is sufficient for Keeling plot analysis to determine the carbon isotope composition of ecosystem-respired CO2, or ?13CR-eco. We now seek to determine, 1) What is the spatial "footprint" of ?13CR- eco measurements, and how does this footprint vary over time? 2) What is the relationship between ?13CR-eco and measurements of isofluxes from soils and foliage across a range of specific sites in the watershed? 3) What is the relationship between ?13CR-eco and carbon cycle processes in the watershed? To answer these questions we conducted extensive measurements of atmospheric processes, augmented by experimental releases of an inert gas (SF6) in collaboration with Dr. Brian Lamb, Washington State University. We installed and instrumented eight plots along a ridge-to-ridge transect; we are continuously measuring above- and belowground microclimate in all plots and in a subset of plots we are continuously measuring sapflow and periodically measuring soil and leaf respiration and their isotopic composition. Atmospheric analyses indicated that air collected for Keeling plot analysis represented a well-mixed sample of all or nearly all of the watershed, and for several hours of most nights this footprint was stable. Respiratory fluxes and isofluxes from both soils and foliage varied both temporally and spatially; the variation among plots was often greater than the temporal variation of a particular plot over the growing season. Scaled to the ecosystem level, respiratory fluxes from foliage exceeded soil fluxes by as much as a factor of two, and fluxes from the south-facing slope were significantly and consistently greater than from the north- facing slope. Consistent with these findings and with atmospheric analyses, ?13CR-eco measured at the tower appeard to be related more closely with concurrent rather than lagged canopy processes, and influenced by conditions throughout the watershed rather than proximal to the tower. We are developing an ecohydrological modeling approach to explore these relationships in more detail. Ultimately we hope to "invert" the model to use ?13CR-eco to monitor carbon cycle processes at the watershed scale on a continuing basis.

Bond, B. J.; Barnard, H.; Conklin, D.; Hauck, M.; Kayler, Z.; Mix, A. C.; Phillips, C.; Pypker, T.; Sulzman, E.; Unsworth, M.

2006-12-01

175

Ocean Fertilization for Sequestration of Carbon Dioxide from the Atmosphere  

NASA Astrophysics Data System (ADS)

The ocean is a major sink for both preindustrial and anthropogenic carbon dioxide. Both physically and biogeochemically driven pumps, termed the solubility and biological pump, respectively Fig.5.1) are responsible for the majority of carbon sequestration in the ocean's interior [1]. The solubility pump relies on ocean circulation - specifically the impact of cooling of the upper ocean at high latitudes both enhances the solubility of carbon dioxide and the density of the waters which sink to great depth (the so-called deepwater formation) and thereby sequester carbon in the form of dissolved inorganic carbon (Fig.5.1). The biological pump is driven by the availability of preformed plant macronutrients such as nitrate or phosphate which are taken up by phytoplankton during photosynthetic carbon fixation. A small but significant proportion of this fixed carbon sinks into the ocean's interior in the form of settling particles, and in order to maintain equilibrium carbon dioxide from the atmosphere is transferred across the air-sea interface into the ocean (the so-called carbon drawdown) thereby decreasing atmospheric carbon dioxide (Fig.5.1).Fig.5.1

Boyd, Philip W.

176

Energy Prices, Taxes and Carbon Dioxide Emissions  

Microsoft Academic Search

Taxes levied on the carbon content of fuels (carbon taxes) are being considered in many OECD countries as a possible policy instrument to reduce carbon dioxide emissions. This paper first reviews the policy response in Member countries to the threat of global warming. It then discusses the link between carbon emission intensities and current energy prices, touching also on the

Peter Hoeller; Markku Wallin

1991-01-01

177

Global food insecurity. Treatment of major food crops with elevated carbon dioxide or ozone under large-scale fully open-air conditions suggests recentmodelsmayhaveoverestimatedfutureyields  

Microsoft Academic Search

Predictions of yield for the globe's major grain and legume arable crops suggest that, with a moderate temperature increase, production may increase in the temperate zone, but decline in the tropics. In total, global food supply may show little change. This security comes from inclusion of the direct effect of rising carbon dioxide (CO2) concentration, (CO2), which significantly stimulates yield

Stephen P. Long; Elizabeth A. Ainsworth; Andrew D. B. Leakey; Patrick B. Morgan

178

Carbon dioxide capture process with regenerable sorbents  

DOEpatents

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.

Pennline, Henry W. (Bethel Park, PA); Hoffman, James S. (Library, PA)

2002-05-14

179

Reaction of yttrium polonides with carbon dioxide  

Microsoft Academic Search

It has been proved that heating of yttrium and tantalum in carbon dioxide to 500 and 800°C alters the gas phase composition, causing formation of carbon monoxide and reduction of oxygen content. A study of the thermal stability of yttrium polonides in carbon dioxide showed that yttrium sesqui- and monopolonides decompose at 400-430°C. The temperature dependence of the vapor pressure

A. S. Abakumov; A. D. Khokhlov; N. F. Reznikova

1986-01-01

180

Effects of pulses of elevated carbon dioxide concentration on stomatal conductance and photosynthesis in wheat and rice  

Technology Transfer Automated Retrieval System (TEKTRAN)

Free air carbon dioxide enrichment (FACE) systems typically expose plants to pulses of carbon dioxide concentrations considerably above the control set-point, in addition to increasing the mean concentration. The importance of such pulses of higher carbon dioxide concentrations to plant function is...

181

Community study of spontaneous abortions: Relation to occupation and air pollution by sulfur dioxide, hydrogen sulfide, and carbon disulfide  

Microsoft Academic Search

Spontaneous abortions were analyzed in an industrial community in Finland in relation to the occupation of women and their husbands, and to the level of air pollution in the family's residential area. Information on abortions and births was obtained from the hospital discharge register; information on the women and their families was obtained from the files of the population and

Kari Hemminki; Marja-Liisa Niemi

1982-01-01

182

SEQUESTERING CARBON DIOXIDE IN COALBEDS  

SciTech Connect

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 Fruitland coal and on activated carbon show that: (a) the Gibbs adsorption isotherm for CO{sub 2} under study exhibits typical adsorption behavior for supercritical gas adsorption, and (b) a slight variation from Type I absolute adsorption may be observed for CO{sub 2}, but the variation is sensitive to the estimates used for adsorbed phase density. (5) The experimental data were used to evaluate the predictive capabilities of various adsorption models, including the Langmuir/loading ratio correlation, a two-dimensional cubic equation of state (EOS), a new two-dimensional (2-D) segment-segment interactions equation of state, and the simplified local density model (SLD). Our model development efforts have focused on developing the 2-D analog to the Park-Gasem-Robinson (PGR) EOS and an improved form of the SLD model. The new PGR EOS offers two advantages: (a) it has a more accurate repulsive term, which is important for reliable adsorption predictions, and (b) it is a segment-segment interactions model, which should more closely describe the gas-coal interactions during the adsorption process. In addition, a slit form of the SLD model was refined to account more precisely for heterogeneity of the coal surface and matrix swelling. In general, all models performed well for the Type I adsorption exhibited by methane, nitrogen, and carbon dioxide up to 8.3 MPa (average deviations within 2%). In comparison, the SLD model represented the adsorption behavior of all fluids considered within 5% average deviations, including the near-critical behavior of carbon dioxide beyond 8.3 MPa (1200 psia). Work is in progress to (a) derive and implement the biporous form of the SLD model, which would expand the number of structural geometries used to represent the heterogeneity of coal surface; and (b) extend the SLD model to mixture predictions. (6) Proper reduction of our adsorption data requires accurate gas-phase compressibility (Z) factors for methane, ethane, nitrogen and carbon dioxide and their mixtures to properly analyze our experimental adsorption data. A careful evaluation of t

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

2001-06-15

183

Historical and present developments of ejector refrigeration systems with emphasis on transcritical carbon dioxide air-conditioning applications  

Microsoft Academic Search

This paper gives an overview of historical and present developments on how ejectors can be utilized to improve the performance of air-conditioning and refrigeration systems. Research on ejector refrigeration cycles that utilize low-grade energy sources to produce cooling is summarized. Another major class of ejector refrigeration cycles that is described tries to recover expansion work by means of a two-phase

Stefan Elbel

2011-01-01

184

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

SciTech Connect

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

Ziska, L.H. [USDA-ARS, Beltsville, MD (United States); Namuco, O.; Moya, T.; Quilang, J. [International Rice Research Inst., Manila (Philippines)

1997-01-01

185

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

Microsoft Academic Search

Research on the global carbon cycle and the effects of increased carbon dioxide on the global climate system is reported. Environmental and societal effects related to COâ and environmental control technology for COâ are also discussed. Lists of research projects and reports and publications of the Carbon Dioxide and Climate Research Program are included. An expanded COâ monitoring network is

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

1980-01-01

186

Water and Carbon Removal from Carbon Dioxide Reduction Systems.  

National Technical Information Service (NTIS)

Methods suitable for use in a weightless environment for removing water and carbon from carbon dioxide reduction process systems were investigated. Water removal studies were conducted using a porous metal, plate-type, condenser-separator to remove the wa...

A. D. Babinsky S. J. Derezinski

1966-01-01

187

The oxygen uptake, in air and in 5% O 2 , and the carbon dioxide output, of stored potato tubers  

Microsoft Academic Search

Oxygen uptake at harvest varied from c. 40 ml kg?1h?1 at 10°C, in very immature, to c. 3–5 ml kg?1h?1 in mature tubers. The O2 status of the tuber normally would allow uptake by a low-affinity oxidase (Km=1.5×10?4M) as well as by cytochrome-c-oxidase (suggestedKm=7×10?8M). Separation was attempted by measuring uptake in air and 5% O2, oxygen status being derived from

W. G. Burton

1974-01-01

188

End-tidal carbon dioxide as a measure of arterial carbon dioxide during intermittent mandatory ventilation  

Microsoft Academic Search

To determine if end-tidal carbon dioxide tension (PetCO2) is a clinically reliable indicator of arterial carbon dioxide tension (PaCO2) under conditions of heterogeneous tidal volumes and ventilation-perfusion inequality, we examined the expiratory gases of\\u000a 25 postcardiotomy patients being weaned from ventilator support with intermittent mandatory ventilation. Using a computerized\\u000a system that automatically sampled airway flow, pressure, and expired carbon dioxide

Matthew B. Weinger; John E. Britain

1987-01-01

189

LIFETIME OF EXCESS ATMOSPHERIC CARBON DIOXIDE  

EPA Science Inventory

We explore the effects of a changing terrestrial biosphere on the atmospheric residende time of carbon dioxide using three simple ocean carbon cycling models and a model of global terrestrial carbon cycling. e find differences in model behavior associated with the assumption of a...

190

Field assessment of a snap bean ozone bioindicator system under elevated ozone and carbon dioxide in a free air system.  

PubMed

Ozone-sensitive (S156) and -tolerant (R123 and R331) genotypes of snap bean (Phaseolus vulgaris L.) were tested as a plant bioindicator system for detecting O(3) effects at current and projected future levels of tropospheric O(3) and atmospheric CO(2) under field conditions. Plants were treated with ambient air, 1.4× ambient O(3) and 550 ppm CO(2) separately and in combination using Free Air Concentration Enrichment technology. Under ambient O(3) concentrations pod yields were not significantly different among genotypes. Elevated O(3) reduced pod yield for S156 (63%) but did not significantly affect yields for R123 and R331. Elevated CO(2) at 550 ppm alone did not have a significant impact on yield for any genotype. Amelioration of the O(3) effect occurred in the O(3) + CO(2) treatment. Ratios of sensitive to tolerant genotype pod yields were identified as a useful measurement for assessing O(3) impacts with potential applications in diverse settings including agricultural fields. PMID:22507388

Burkey, Kent O; Booker, Fitzgerald L; Ainsworth, Elizabeth A; Nelson, Randall L

2012-04-14

191

Carbon Dioxide Power Plant of Medium Capacity.  

National Technical Information Service (NTIS)

This article considers the prospect of creating highly economical and compact carbon dioxide power plants for average unit capacities and results are cited of the study of basic components of 50 megawatt installation.

B. S. Tishchenko D. P. Gokhshtein E. K. Olesevich E. L. Dekhtyarev V. N. Khalaidzhi

1968-01-01

192

Carbon Dioxide Emission Factors for Coal  

EIA Publications

The Energy Information Administration (EIA) has developed factors for estimating the amount of carbon dioxide emitted, accounting for differences among coals, to reflect the changing "mix" of coal in U.S. coal consumption.

William Watson

1994-08-01

193

Carbon dioxide hazards in general aviation.  

PubMed

There are numerous reports of carbon dioxide fire extinguishers or significant loads of dry ice causing actual or potential carbon dioxide intoxication leading to accidents or incidents, both in the military and in the airlines. To evaluate the significance of the problem in general aviation, dry ice sublimation reported in literature and measured sublimation was theoretically applied to general aviation aircraft, and carbon dioxide from fire extinguishers was measured, both in static and flight condition. The results indicate that the use of carbon dioxide fire extinguishers or the transportation under some conditions of dry ice could produce levels which could cause severe anxiety due to respiratory stimulation or actually produce pilot impairment and contribute to or cause accidents. PMID:856155

Gibbons, H L

1977-03-01

194

Atmospheric carbon dioxide record from flask measurements at Lampedusa Island  

NSDL National Science Digital Library

Air samples from Lampedusa Island, located south of Sicily in the Mediterranean sea, were collected weekly from May 1992 through December 2000 and analyzed for carbon dioxide content. "On the basis of annual averages calculated from monthly averages, CO2 levels at Lampedusa Island have risen from 360.80 in 1993 to 371.27 in 2000. The data show an average trend of +1.5 ppmv/y." The data from the study, newly available this month from the Carbon Dioxide Information Analysis Center (CDIAC), include a plot of mean carbon dioxide concentration (ppmv) against time and a text table of the annual mean values. Methods, notes, and references are also provided.

Monteleone, Francesco.; Di Sarra, Alcide.; Ciattaglia, Luigi.; Chamard, Paolo.

2001-01-01

195

Magnesian calcite sorbent for carbon dioxide capture  

Microsoft Academic Search

Magnesian calcite with controlled properties was synthesized for the removal of carbon dioxide. The results from characterization, reactivity and CO2 capture capacity for different synthesis conditions are reported. The magnesian calcite samples (CaCO3:MgCO3) were synthesized by the coprecipitation of specific amounts of commercially available CaO and MgO by carbon dioxide. Characterization was done with BET, SEM\\/EDS, particle size analysis and

James C. Mabry; Kanchan Mondal

2011-01-01

196

[Ocular carbon dioxide reactivity in retinitis pigmentosa. Perimetry results].  

PubMed

Ocular pulse volumes (POV) measured by oculo-oscillo-dynamography were markedly reduced in Retinopathia pigmentosa (R.P.) patients (n = 52) compared to healthy subjects (n = 107). During breathing increased carbon dioxide concentrations (6.5%) POV returned nearly to normal values [15,17]. In an attempt to evaluate the effects of increased inspiratory carbon dioxide concentrations on the visual field in R.P. patients the following study was performed. In 24 patients (24 right eyes, 23 left eyes) suffering from a clinically and electrophysiologically confirmed R.P. kinetic visual field testing was performed. After a standardized kinetic Goldmann-perimetry (V/4; III/4; I/4; I/3; I/2; I/1) during breathing normal air the visual field testing was repeated during breathing increased carbon dioxide concentrations (6.5%). The visual field area was measured with a planimeter (Hewlett Packard 9874 A Digitalizer) separately for each isopter. For a better comparison of the results the change in the visual field was expressed as a percentage value of the initial visual field area of each isopter. During breathing increased carbon dioxide concentrations the visual field area improved, expressed as the median of all isopters, by x = 29% in 24 right eyes and by x = 18% in 23 left eyes. The results presented suggest that breathing of increased carbon dioxide concentrations improve ocular hemodynamics and furthermore have a beneficial effect on the remaining visual field area in R.P. patients. PMID:8219642

Tacke, C M; Pillunat, L E; Lang, G K

1993-10-01

197

Sex Differences in Panic-Relevant Responding to a 10% Carbon Dioxide-Enriched Air Biological Challenge  

PubMed Central

The current study examined sex differences in psychological (i.e., self-reported anxiety, panic symptoms, and avoidance) and physiological (i.e., heart rate and skin conductance level) response to, and recovery from, a laboratory biological challenge. Participants were a community-recruited sample of 128 adults (63.3% women; Mage = 23.2 years, SD = 8.9) who underwent a 4-minute 10% CO2-enriched air biological challenge. As predicted, women reported more severe physical panic symptoms and avoidance (i.e., less willingness to participate in another challenge) and demonstrated increased heart rate as compared to men above and beyond the variance accounted for by other theoretically-relevant variables (recent panic attack history, neuroticism, and anxiety sensitivity). Additionally, women demonstrated a faster rate of recovery with respect to heart rate compared to men. These results are in line with literature documenting sex-specific differences in panic psychopathology, and results are discussed in the context of possible mechanisms underlying sex differences in panic vulnerability.

Nillni, Yael I.; Berenz, Erin C.; Rohan, Kelly J.; Zvolensky, Michael J.

2011-01-01

198

Sex differences in panic-relevant responding to a 10% carbon dioxide-enriched air biological challenge.  

PubMed

The current study examined sex differences in psychological (i.e., self-reported anxiety, panic symptoms, and avoidance) and physiological (i.e., heart rate and skin conductance level) response to, and recovery from, a laboratory biological challenge. Participants were a community-recruited sample of 128 adults (63.3% women; M(age)=23.2 years, SD=8.9) who underwent a 4-min 10% CO(2)-enriched air biological challenge. As predicted, women reported more severe physical panic symptoms and avoidance (i.e., less willingness to participate in another challenge) and demonstrated increased heart rate as compared to men above and beyond the variance accounted for by other theoretically relevant variables (recent panic attack history, neuroticism, and anxiety sensitivity). Additionally, women demonstrated a faster rate of recovery with respect to heart rate compared to men. These results are in line with literature documenting sex-specific differences in panic psychopathology, and results are discussed in the context of possible mechanisms underlying sex differences in panic vulnerability. PMID:22115836

Nillni, Yael I; Berenz, Erin C; Rohan, Kelly J; Zvolensky, Michael J

2011-11-06

199

A correlation of optimal heat rejection pressures in transcritical carbon dioxide cycles  

Microsoft Academic Search

In this work, a cycle simulation model has been developed to optimize the coefficient of performance (COP) of transcritical carbon dioxide air-conditioning cycles. The analysis shows that the COP of the transcritical carbon dioxide cycle varies nonmonotonically with the heat rejection pressure; a maximum COP occurs at an optimal heat rejection pressure. It is further revealed that the values of

S. M. Liao; T. S. Zhao; A. Jakobsen

2000-01-01

200

Capnographic Monitoring during Endoscopic Submucosal Dissection with Patients under Deep Sedation: A Prospective, Crossover Trial of Air and Carbon Dioxide Insufflations  

Microsoft Academic Search

Background and Aims: The safety of carbon dioxide (CO2) insufflation has not been fully established for esophageal and gastric endoscopic submucosal dissection (ESD) under deep sedation, because CO2 retention is not only caused by CO2 insufflation but also by the sedation level and the patient’s respiratory status. To clarify the clinical safety of CO2 insufflation, we conducted a crossover trial

Akihito Takano; Masaaki Kobayashi; Manabu Takeuchi; Satoru Hashimoto; Ken-ichi Mizuno; Rintaro Narisawa; Yutaka Aoyagi

2011-01-01

201

Mineralization strategies for carbon dioxide sequestration  

SciTech Connect

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

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

2003-01-01

202

Comparison of Global Model Results from the Carbon-Land Model Intercomparison Project (C-LAMP) with Free-Air Carbon Dioxide Enrichment (FACE) Manipulation Experiments  

SciTech Connect

Free-Air CO{sub 2} Enrichment (FACE) manipulation experiments have been carried out at a handful of sites to gauge the response of the biosphere to significant increases in atmospheric [CO{sub 2}]. Early synthesis results from four temperate forest sites suggest that the response of net primary productivity (NPP) is conserved across a broad range of productivity with a stimulation at the median of 23 {+-} 2% when the surrounding air [CO{sub 2}] was raised to 550{approx}ppm. As a part of the Carbon-Land Model Intercomparison Project (C-LAMP), a community-based model-data comparison activity, the authors have performed a global FACE modeling experiment using two terrestrial biogeochemistry modules, CLM3-CASA and CLM3-CN, coupled to the National Center for Atmospheric Research (NCAR) Community Climate System Model (CCSM). The two models were forced with an improved NCEP/NCAR reanalysis data set and reconstructed atmospheric [CO{sub 2}] and N deposition data through 1997. At the beginning of 1997 in the transient simulations, global atmospheric [CO{sub 2}] was abruptly raised to 550{approx}ppm, the target value used at the FACE sites. In the control runs, [CO{sub 2}] continued to rise following observations until 2004, after which it was held constant out to year 2100. In both simulations, the last 25 years of reanalysis forcing and a constant N deposition were applied after year 2004. Across all forest biomes, the NPP responses from both models are weaker than those reported for the four FACE sites. Moreover, model responses vary widely geographically with a decreasing trend of NPP increases from 40{sup o}N to 70{sup o}N. For CLM3-CASA, the largest responses occur in arid regions of western North America and central Asia, suggesting that responses are most strongly influenced by increased water use efficiency for this model. CLM3-CN exhibits consistently weaker responses than CLM3-CASA' with the strongest responses in central Asia, but significantly constrained by N limitation. C-LAMP is a sub-project of the Computational Climate Science End Station led by Dr. Warren Washington, using computing resources at the U.S. Department of Energy's National Center for Computational Sciences (NCCS).

Hoffman, Forrest M [ORNL; Randerson, Jim [University of California, Irvine; Fung, Inez [University of California, Berkeley; Thornton, Peter E [ORNL; Covey, Curtis [Lawrence Livermore National Laboratory (LLNL); Bonan, Gordon [National Center for Atmospheric Research (NCAR); Running, Steven [University of Montana, Missoula; Norby, Richard J [ORNL

2008-01-01

203

Comparison of Global Model Results from the Carbon-Land Model Intercomparison Project (C-LAMP) with Free-Air Carbon Dioxide Enrichment (FACE) Manipulation Experiments  

NASA Astrophysics Data System (ADS)

Free-Air CO2 Enrichment (FACE) manipulation experiments have been carried out at a handful of sites to gauge the response of the biosphere to significant increases in atmospheric [CO2]. Early synthesis results from four temperate forest sites suggest that the response of net primary productivity (NPP) is conserved across a broad range of productivity with a stimulation at the median of 23±2% when the surrounding air [CO2] was raised to 550~ppm. As a part of the Carbon-Land Model Intercomparison Project (C-LAMP), a community-based model-data comparison activity, the authors have performed a global FACE modeling experiment using two terrestrial biogeochemistry modules, CLM3-CASA' and CLM3-CN, coupled to the National Center for Atmospheric Research (NCAR) Community Climate System Model (CCSM). The two models were forced with an improved NCEP/NCAR reanalysis data set and reconstructed atmospheric [CO2] and N deposition data through 1997. At the beginning of 1997 in the transient simulations, global atmospheric [CO2] was abruptly raised to 550~ppm, the target value used at the FACE sites. In the control runs, [CO2] continued to rise following observations until 2004, after which it was held constant out to year 2100. In both simulations, the last 25 years of reanalysis forcing and a constant N deposition were applied after year 2004. Across all forest biomes, the NPP responses from both models are weaker than those reported for the four FACE sites. Moreover, model responses vary widely geographically with a decreasing trend of NPP increases from 40°N to 70°N. For CLM3- CASA', the largest responses occur in arid regions of western North America and central Asia, suggesting that responses are most strongly influenced by increased water use efficiency for this model. CLM3-CN exhibits consistently weaker responses than CLM3-CASA' with the strongest responses in central Asia, but significantly constrained by N limitation. C-LAMP is a sub-project of the Computational Climate Science End Station led by Dr. Warren Washington, using computing resources at the U.S. Department of Energy's National Center for Computational Sciences (NCCS). lamp/

Hoffman, F. M.; Randerson, J. T.; Fung, I.; Thornton, P.; Covey, C.; Bonan, G.; Running, S.; Norby, R.

2008-12-01

204

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

Code of Federal Regulations, 2010 CFR

...179.102-1 Carbon dioxide, refrigerated liquid...cars used to transport carbon dioxide, refrigerated liquid...tanks must be made of carbon steel conforming...Charpy V-Notch energy absorption requirements...

2010-10-01

205

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

Code of Federal Regulations, 2010 CFR

...179.102-1 Carbon dioxide, refrigerated liquid...cars used to transport carbon dioxide, refrigerated liquid...tanks must be made of carbon steel conforming...Charpy V-Notch energy absorption requirements...

2009-10-01

206

A Solid Electrolyte Carbon Dioxide Reduction System.  

National Technical Information Service (NTIS)

An investigation of solid electrolyte cells utilizing a 90 mole % ZrO2-10 mole % Y2O3 electrolyte and platinum electrodes for the reduction of carbon dioxide to carbon monoxide and oxygen was carried out. At 1000 C, oxygen production efficiency is less th...

H. W. Chandler L. J. Howell

1969-01-01

207

A Solid Electrolyte Carbon Dioxide Reduction System.  

National Technical Information Service (NTIS)

Solid electrolyte cells utilizing a 90 mole percent Zr02(-10) mole percent Y203 electrolyte and platinum electrodes were used for the reduction of carbon dioxide to carbon monoxide and oxygen. Methods of fabricating multicell units were investigated and t...

H. W. Chandler L. J. Howell

1968-01-01

208

Effect of carbon dioxide on nitrification rates  

Microsoft Academic Search

Lab-scale ideal mixed, aerated reactors were employed to test the influence of carbon dioxide (CO2) on the growth rate of a nitrifier community. The buffer medium used did not contain any carbon sources. Reactors were inoculated alternatively with sludge from a nitrifying membrane assisted bioreactor, reflecting autotrophic material, or with sludge from a plant having denitrification and nitrification steps, which

M. Denecke; T. Liebig

2003-01-01

209

Where in the World is Carbon Dioxide?  

NSDL National Science Digital Library

This three part activity has students set up experiments to help them better understand the atmospheric portion of the carbon cycle. From this activity, they will be able to explain the concept of sources and sinks as they relate to carbon dioxide, the use of indicator solution bromothymol blue (BTB) to reveal the presence of carbon dioxide, and the qualitative differences between animal and fossil fuel sources of global carbon dioxide. The student guide has an overall description of all three parts of the activity, lists of materials, the procedure and observations and questions. The instructor guide contains detailed background material, learning goals, alignment to national standards, grade level/time, details on materials and preparation, procedure, assessment ideas, and modifications for alternative learners.

210

Apparatus for extracting and sequestering carbon dioxide  

DOEpatents

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.

Rau, Gregory H. (Castro Valley, CA); Caldeira, Kenneth G. (Livermore, CA)

2010-02-02

211

Method for extracting and sequestering carbon dioxide  

DOEpatents

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

Rau, Gregory H. (Castro Valley, CA); Caldeira, Kenneth G. (Livermore, CA)

2005-05-10

212

SEQUESTERING CARBON DIOXIDE IN COALBEDS  

SciTech Connect

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

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

2003-03-10

213

SEQUESTERING CARBON DIOXIDE IN COALBEDS  

SciTech Connect

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

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

2003-04-30

214

Carbon Dioxide Fluxes in the Global Ocean  

Microsoft Academic Search

\\u000a Atmospheric carbon dioxide concentration is one of the key variables of the ‘Earth system’ — the web of interactions between\\u000a the atmosphere, oceans, soils and living things that determines conditions at the Earth surface. Atmospheric CO2 plays several roles in this system. For example, it is the carbon source for nearly all terrestrial green plants, and the\\u000a source of carbonic

Andrew J. Watson; James C. Orr

215

Global deforestation: contribution to atmospheric carbon dioxide  

Microsoft Academic Search

A study of effects of terrestrial biota on the amount of carbon dioxide in the atmosphere suggests that the global net release of carbon due to forest clearing between 1960 and 1980 was between 135 X 10¹⁵ and 228 X 10¹⁵ grams. Between 1.8 X 10¹⁵ and 4.7 X 10¹⁵ grams of carbon were released in 1980, of which nearly

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

1983-01-01

216

Deep sixing carbon dioxide from power plants  

NSDL National Science Digital Library

The injection and storage of carbon dioxide into the Atlantic, Pacific, and Indian Oceans was simulated over a 500-year period in order to explore how climate change could alter ocean circulation and the ability of the ocean to store carbon for long periods. It was found that climate change increased the duration that injected carbon remained in the Atlantic, but had no influence in the Pacific and Indian oceans.

Jain, Atul K.; Cao, Long; Agu

217

Enhancing carbon dioxide sorption rates using hygroscopic additives  

SciTech Connect

A carbon dioxide sorbent useful in the removal of carbon dioxide from a gaseous stream is described, comprising: a. a metal oxide; b. an alkali metal carbonate; and c. an alkali fluoride; whereby said sorbent is capable of absorbing carbon dioxide in relative humidities below about 25%.

Nalette, T.A.; Birbara, P.J.

1993-05-25

218

Do Plants Really Use Carbon Dioxide?  

NSDL National Science Digital Library

This experiment demonstrates that plants use carbon dioxide during photosynthesis. Four Teaching Tanks (commercially available, narrow tanks) are filled with water and bromthymol blue indicator, and Elodea plants are added to two of the tanks. Blowing through a straw into each tank dissolves carbon dioxide into the water and turns the indicator yellow. The tanks are sealed with clay, and a pair of tanksâone tank with Elodea and one withoutâis put in sunlight, while the other pair is put in darkness. After an hour, the tank with Elodea in sunlight will have returned to blue color. Learners can infer that the carbon dioxide in that tank has been used by the Elodea, since the water in "control" tanks remains yellow. Though designed as a demonstration, this activity could be adapted to allow varying degrees of learner hands-on involvement, and higher grade learners could potentially do all the steps without a demonstrator.

Products, American E.

1992-01-01

219

Energy levels, intensities, and linewidths of atmospheric carbon dioxide bands  

NASA Astrophysics Data System (ADS)

Spectroscopic constants are given for eight isotopic variants of carbon dioxide which provide energy levels for transitions required for terrestrial atmospheric IR absorption. A new tabulation is also furnished with bands considered for the latest HITRAN molecular database. This list provides improved band intensities and Herman-Wallis coefficients generated from recent high-resolution measurements and theoretical calculations. Rotationally-dependent air- and self-broadened halfwidths are provided from a survey of recent experiments.

Rothman, L. S.; Hawkins, R. L.; Wattson, R. B.; Gamache, R. R.

1992-12-01

220

Carbon Dioxide in the Atmosphere and in Atlantic Ocean Water  

Microsoft Academic Search

An investigation of carbon dioxide partial pressures in the atmosphere and surface ocean conducted as part of a cooperative study under the general sponsorship of the International Geophysical Year is summarized. Results are given for about 470 hours of air analyses and 200 individual surface ocean water measurements made from 1957 to 1959 between 60øN and 58øS. Over the Atlantic

Taro Takahashi

1961-01-01

221

Reduction of Atmospheric Radiocarbon Concentration by Fossil Fuel Carbon Dioxide and the Mean Life of Carbon Dioxide in the Atmosphere  

Microsoft Academic Search

It is generally accepted that the combustion of fossil fuels over the period 1860 to 1954 has produced an amount of carbon dioxide, containing no radiocarbon, that is equal to approximately 13% of the carbon dioxide in the atmosphere. The addition of this 'old' carbon dioxide to the atmosphere has observably disturbed the steady-state distribution of carbon-14 in nature. In

G. J. Fergusson

1958-01-01

222

Synthesis of Fluoropolymers in Supercritical Carbon Dioxide  

NASA Astrophysics Data System (ADS)

Fluoropolymers are used in many technologically demanding applications because of their balance of high-performance properties. A significant impediment to the synthesis of variants of commercially available amorphous fluoropolymers is their general insolubility in most solvents except chlorofluorocarbons (CFCs). The environmental concerns about CFCs can be circumvented by preparing these technologically important materials in supercritical fluids. The homogeneous solution polymerization of highly fluorinated acrylic monomers can be achieved in supercritical carbon dioxide by using free radical methods. In addition, detailed decomposition rates and efficiency factors were measured for azobisisobutyronitrile in supercritical carbon dioxide and were compared to those obtained with conventional liquid solvents.

Desimone, J. M.; Guan, Zihibin; Elsbernd, C. S.

1992-08-01

223

76 FR 27908 - Approval and Promulgation of Air Quality Implementation Plans; Massachusetts; Revised Carbon...  

Federal Register 2010, 2011, 2012, 2013

...requirements of the revised carbon monoxide plan for Lowell...protection, Air pollution control, Carbon monoxide, Incorporation by...relations, Lead, Nitrogen dioxide, Ozone, Particulate matter...52.1132 Control strategy: Carbon Monoxide. * * * * *...

2011-05-13

224

Use of carbon dioxide in the chemical synthesis technologies, plasma gasification and carbon production  

NASA Astrophysics Data System (ADS)

The modern electric power sector is based on burning of carbonaceous substances (coal, oil, natural gas, etc.). Large power stations are powerful local sources of carbon dioxide. Inconstancy of the electric power demand leads to increase in CO2 specific emissions, as the output power is basically higher than required one by the power network. One of promising ways of increase of operating efficiency of power stations is use of surpluses of the generated electric power in plasma technologies. The paper deals with the opportunity to use the plasma technologies in processes of methanol and methane production from carbon dioxide. Comparison of ranges of key parameters of plasma gasification of wood by air, carbon dioxide, and steam is presented. Also, use of CO2 for pure carbon production is examined.

Rutberg, Ph G.; Kuznetsov, V. A.; Bratsev, A. N.; Popov, V. E.; Shtengel', S. V.; Ufimtsev, A. A.

2011-03-01

225

Global deforestation: contribution to atmospheric carbon dioxide  

SciTech Connect

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

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

1983-12-09

226

Relative permeabilities of plastic films to water and carbon dioxide.  

PubMed

The permeabilities of several types of plastic films to water and to carbon dioxide were measured. No material was found to have a carbon dioxide permeability as great as its water permeability. PMID:16656548

Woolley, J T

1967-05-01

227

21 CFR 868.1400 - Carbon dioxide gas analyzer.  

Code of Federal Regulations, 2010 CFR

... (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon dioxide in a gas mixture to aid in...techniques such as chemical titration, absorption of infrared radiation, gas...

2009-04-01

228

21 CFR 868.1400 - Carbon dioxide gas analyzer.  

Code of Federal Regulations, 2010 CFR

... (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon dioxide in a gas mixture to aid in...techniques such as chemical titration, absorption of infrared radiation, gas...

2010-04-01

229

40 CFR 86.1524 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Carbon dioxide analyzer calibration. 86.1524 Section 86.1524 Protection...Procedures § 86.1524 Carbon dioxide analyzer calibration. (a) The calibration requirements for the dilute-sample CO2...

2013-07-01

230

Carbon dioxide absorption with aqueous potassium carbonate promoted by piperazine  

Microsoft Academic Search

Many commercial processes for the removal of carbon dioxide from high-pressure gases use aqueous potassium carbonate systems promoted by secondary amines. This paper presents thermodynamic and kinetic data for aqueous potassium carbonate promoted by piperazine. Research has been performed at typical absorber conditions for the removal of CO2 from flue gas.Piperazine, used as an additive in 20–30wt% potassium carbonate, was

J. Tim Cullinane; Gary T. Rochelle

2004-01-01

231

Discussion of Refrigeration Cycle Using Carbon Dioxide as Refrigerant  

NASA Astrophysics Data System (ADS)

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

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

232

Carbon dioxide emission from european estuaries  

PubMed

The partial pressure of carbon dioxide (pCO2) in surface waters and related atmospheric exchanges were measured in nine European estuaries. Averaged fluxes over the entire estuaries are usually in the range of 0.1 to 0.5 mole of CO2 per square meter per day. For wide estuaries, net daily fluxes to the atmosphere amount to several hundred tons of carbon (up to 790 tons of carbon per day in the Scheldt estuary). European estuaries emit between 30 and 60 million tons of carbon per year to the atmosphere, representing 5 to 10% of present anthropogenic CO2 emissions for Western Europe. PMID:9774261

Frankignoulle; Abril; Borges; Bourge; Canon; Delille; Libert; Theate

1998-10-16

233

The urgent need for carbon dioxide sequestration  

SciTech Connect

The danger of global warming has put in question the use of fossil fuels which constitute the most abundant and most reliable energy resource. Meeting the ever growing world demand for cheap energy, while simultaneously achieving the required drastic reduction in CO{sub 2} emissions can only be accomplished by actively preventing carbon dioxide generated in the combustion of fuels from accumulating in the atmosphere, i.e. by sequestration. Sequestration is possible and economically viable and is currently the only realistic solution to the dilemma of CO{sub 2} emissions. The authors have developed a very promising approach that disposes of carbon dioxide by chemically combining it in an exothermic reaction with readily available minerals to form carbonates. The resulting carbonates are stable solids that are known to be environmentally benign and to be stable on geological time scales. This stands in contrast to most other methods that do not appear to fully solve the long term problem.

Lackner, K.S.; Butt, D.P.; Jensen, R.; Ziock, H.

1998-09-01

234

Platinum catalyst for forming carbon dioxide  

SciTech Connect

This patent describes an improvement in a platinum wire catalytic apparatus for catalyzing the reaction of carbon monoxide and oxygen to form carbon dioxide by directly heating the catalyst to an activation temperature of about 1000{degrees} C. The improvement comprises a layer of platinum black deposited on the surface of the platinum wire to form a coating whereby the wire with the coating is directly heated to an activation temperature within the range of about 150 to 300{degrees} C.

McNeil, J.A.; Cohn, D.B.

1991-05-28

235

27 CFR 24.319 - Carbon dioxide record.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Carbon dioxide record. 24.319 Section 24.319 ...WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a...

2010-04-01

236

27 CFR 24.319 - Carbon dioxide record.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Carbon dioxide record. 24.319 Section 24.319 ...WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a...

2009-04-01

237

Leucocyte values in rats and mice following carbon dioxide euthanasia  

Microsoft Academic Search

Leucocyte counts obtained from Wistar rats and CD1 mice following euthanasia with carbon dioxide were compared to leucocyte values obtained using other agents for anaesthesia or euthanasia. In rats, following euthanasia with carbon dioxide, lymphocyte and neutrophil counts in samples taken from the heart were significantly raised compared with sodium barbiturate euthanasia. In mice, following carbon dioxide, total leucocyte counts

G. O. Evans; D. E. C. Smith

1991-01-01

238

Removal of carbon dioxide in geothermal power systems  

Microsoft Academic Search

A process for removing carbon dioxide in geothermal power generating processes employing a geothermal fluid such as geothermal brine containing carbon dioxide, to improve the efficiency of geothermal power generation, comprises introducing an aqueous alkaline solution, preferably an aqueous calcium hydroxide solution, into a vapor stream obtained from the brine during power generation, to remove carbon dioxide from the stream.

Wahl

1982-01-01

239

Carbon Dioxide Enrichment Inhibits Nitrate Assimilation in Wheat and Arabidopsis  

Microsoft Academic Search

The concentration of carbon dioxide in Earth's atmosphere may double by the end of the 21st century. The response of higher plants to a carbon dioxide doubling often includes a decline in their nitrogen status, but the reasons for this decline have been uncertain. We used five independent methods with wheat and Arabidopsis to show that atmospheric carbon dioxide enrichment

Arnold J. Bloom; Martin Burger; Jose Salvador Rubio Asensio; Asaph B. Cousins

2010-01-01

240

Estimated Carbon Dioxide Emissions in 2008: United States  

Microsoft Academic Search

Flow charts depicting carbon dioxide emissions in the United States have been constructed from publicly available data and estimates of state-level energy use patterns. Approximately 5,800 million metric tons of carbon dioxide were emitted throughout the United States for use in power production, residential, commercial, industrial, and transportation applications in 2008. Carbon dioxide is emitted from the use of three

C A Smith; A J Simon; R D Belles

2011-01-01

241

Method of immobilizing carbon dioxide from gas streams  

Microsoft Academic Search

This invention is a method for rapidly and continuously immobilizing carbon dioxide contained in various industrial off-gas streams, the carbon dioxide being immobilized as dry, stable, and substantially water-insoluble particulates. Briefly, the method comprises passing the gas stream through a fixed or fluidized bed of hydrated barium hydroxide to remove and immobilize the carbon dioxide by converting the bed to

David W. Holladay; Gary L. Haag

1979-01-01

242

Method of immobilizing carbon dioxide from gas streams  

Microsoft Academic Search

This invention comprises a method for rapidly and continuously immobilizing carbon dioxide contained in various industrial off-gas streams, the carbon dioxide being immobilized as dry, stable, and substantially water-insoluble particulates. Briefly, the method comprises passing the gas stream through a fixed or fluidized bed of hydrated barium hydroxide to remove and immobilize the carbon dioxide by converting the bed to

D. W. Holladay; G. L. Haag

1979-01-01

243

9 CFR 313.5 - Chemical; carbon dioxide.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 false Chemical; carbon dioxide. 313.5 Section 313.5...LIVESTOCK § 313.5 Chemical; carbon dioxide. The slaughtering of sheep, calves and swine with the use of carbon dioxide gas and the handling in...

2013-01-01

244

CARBON DIOXIDE CONCENTRATION AI NIGHT AFFECTS TRANSLOCATION FROM SOYBEAN LEAVES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Studies have indicated that the concentration of carbon dioxide during the dark period may influence plant dry matter production. It is often suggested that these effects on growth result from effects of carbon dioxide on rates of respiration, but responses of respiration to carbon dioxide remain c...

245

27 CFR 24.319 - Carbon dioxide record.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Carbon dioxide record. 24.319 Section 24.319...WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a...

2013-04-01

246

40 CFR 91.320 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Carbon dioxide analyzer calibration. 91.320 Section 91.320 Protection...91.320 Carbon dioxide analyzer calibration. (a) Prior to its introduction...range with carbon dioxide-in-N2 calibration or span gases having nominal...

2012-07-01

247

40 CFR 86.524-78 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Carbon dioxide analyzer calibration. 86.524-78 Section 86.524-78...524-78 Carbon dioxide analyzer calibration. (a) Prior to its introduction...operating range with carbon dioxide in N2 calibration gases with nominal concentrations...

2013-07-01

248

40 CFR 90.320 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Carbon dioxide analyzer calibration. 90.320 Section 90.320 Protection...90.320 Carbon dioxide analyzer calibration. (a) Prior to its initial use...range with carbon dioxide-in-N2 calibration or span gases having nominal...

2012-07-01

249

40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Carbon dioxide analyzer calibration. 86.1324-84 Section 86.1324-84...1324-84 Carbon dioxide analyzer calibration. Prior to its introduction into...spaced, carbon dioxide-in-N2 calibration or span gases (e.g., 15,...

2013-07-01

250

40 CFR 86.124-78 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Carbon dioxide analyzer calibration. 86.124-78 Section 86.124-78...124-78 Carbon dioxide analyzer calibration. Prior to its introduction into...operating range with carbon dioxide in N2 calibration gases with nominal concentrations...

2013-07-01

251

Urban carbon dioxide in Portland, Oregon  

NASA Astrophysics Data System (ADS)

Ambient concentrations of atmospheric carbon dioxide (CO2) are reported for the Portland, Oregon (USA) metropolitan region since late July, 2009. Three stationary locations were established: a downtown location on the campus of Portland State University; a residential site in southeast Portland; and a rural station on Sauvie Island, located ~30km northwest of Portland in the Columbia River Gorge. Continuous measurements of CO2 at the sites average 400-410ppm and show considerable variability due to CO2 sources, sinks and meteorological drivers of ventilation. Within this variability, a marked 20-30ppm diurnal cycle is observed due to photosynthetic activity and variations in the planetary boundary layer. In-city CO2 concentrations are on average enhanced by 5-6ppm over the Sauvie Island site during upgorge wind conditions, a difference which is greatest in the afternoon. Measurements of the 13C/12C ratio of CO2 in downtown Portland are significantly depleted in 13C relative to 12C compared with background air and suggest that regional CO2 is dominated by petroleum sources (70-80%). High degrees of relationship between CO2 variability and primary air pollutants CO and NO (r2=0.70 to 0.80), measured by the Oregon Department of Environmental Quality at the Southeast Portland location, corroborate this finding and illustrate the importance of traffic emissions on elevated ambient CO2 concentrations. In addition to CO2 at the fixed sites, measurements of street-level CO2 concentrations were obtained using a mobile instrument mounted in a bike trailer. Results from these field data show relatively homogenous CO2 concentrations throughout residential Portland neighborhoods with significant enhancements in CO2 on busy roadways or near areas of traffic congestion.

Bostrom, G. A.; Brooks, M.; Rice, A. L.

2010-12-01

252

New analytical reagents for the determination of sulfur dioxide and carbon monoxide  

Microsoft Academic Search

Four solid reagent methods were developed for the determination of sulfur dioxide in air, and one method was developed to measure carbon monoxide. When applied to filter paper with acetamide as the humectant and 4-phenylcyclohexanone as a bisulfite absorbent, oxohydroxybis(8-hydroxyquinolinyl-) vanadium (V) changes from yellow to black in the presence of sulfur dioxide. The three other methods, also on a

Trump

1987-01-01

253

Diffusion of undecane (1); carbon dioxide (2)  

NASA Astrophysics Data System (ADS)

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) undecane; (2) carbon dioxide

Winkelmann, J.

254

Ocean Acidification: The Other Carbon Dioxide Problem  

NSDL National Science Digital Library

This NOAA video discusses how the ocean absorbs the increased amount of carbon dioxide released into the atmosphere, thereby changing the pH and buffering action of the ocean. These changes in pH are impacting calcifying organisms, such as corals and shellfish, and related food chains and ecosystems.

Noaa; Administration, National O.

255

The Emission Spectrum of Carbon Dioxide  

Microsoft Academic Search

The emission spectrum of carbon dioxide has been studied by the electron beam excitation method used by Smyth and Arnott. The whole range of the spectrum from 6500 to 1400 has been examined and only the bands reported by Fox, Duffendack and Barker in the region from 2700 to 5000 have been observed. A particular effort was made to get

H. D. Smyth

1931-01-01

256

Infrared Spectrum of Carbon Dioxide Anion Radical  

Microsoft Academic Search

Pressed alkali halide disks of infrared spectroscopy have been used as matrices to trap and to stabilize the carbon dioxide anion free radical. The radical was generated by exposing disks containing the formate ion in solid solution to gamma rays from a cobalt source. The ESR, the ultraviolet, and the infrared spectra of the radical have been identified. From the

K. O. Hartman; I. C. Hisatsune

1966-01-01

257

Carbon dioxide storage potential of shales  

Microsoft Academic Search

Options for the geologic storage of carbon dioxide vary from saline aquifers and depleted oil and gas reservoirs to unminable coal seams and abandoned coal mines. Important aspects include the sealing integrity of the cap rock and potential changes in this integrity, owing to the interaction with CO2.In this study, diffusive transport and gas sorption experiments on one well characterised

Andreas Busch; Sascha Alles; Yves Gensterblum; Dirk Prinz; David N. Dewhurst; Mark D. Raven; Helge Stanjek; Bernhard M. Krooss

2008-01-01

258

Catalyst Cartridge for Carbon Dioxide Reduction Unit.  

National Technical Information Service (NTIS)

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...

R. F. Holmes

1973-01-01

259

Carbon Dioxide Reduction Aboard the Space Station.  

National Technical Information Service (NTIS)

Classification of carbon dioxide reduction processes to be used in CO2 processing systems is considered. The advantages and the problems of realization of the processes are considered. The results obtained in the development of a unit prototype based on t...

L. I. Gavrilov V. A. Naumov A. I. Rjabkin T. N. Pavlova N. M. Samsonov

1991-01-01

260

Carbon dioxide balneotherapy and cardiovascular disease  

Microsoft Academic Search

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

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

2010-01-01

261

Carbon dioxide balneotherapy and cardiovascular disease  

Microsoft Academic Search

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

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

2011-01-01

262

Photobiological hydrogen production and carbon dioxide sequestration  

Microsoft Academic Search

Photobiological hydrogen production is an alternative to thermochemical and electrolytic technologies with the advantage of carbon dioxide sequestration. However, it suffers from low solar to hydrogen energy conversion efficiency due to limited light transfer, mass transfer, and nutrient medium composition. The present study aims at addressing these limitations and can be divided in three parts: (1) experimental measurements of the

Halil Berberoglu

2008-01-01

263

Carbon dioxide enhances fragility of ice crystals  

NASA Astrophysics Data System (ADS)

Ice caps and glaciers cover 7% of the Earth, greater than the land area of Europe and North America combined, and play an important role in global climate. The small-scale failure mechanisms of ice fracture, however, remain largely elusive. In particular, little understanding exists about how the presence and concentration of carbon dioxide molecules, a significant component in the atmosphere, affects the propensity of ice to fracture. Here we use atomic simulations with the first-principles based ReaxFF force field capable of describing the details of chemical reactions at the tip of a crack, applied to investigate the effects of the presence of carbon dioxide molecules on ice fracture. Our result shows that increasing concentrations of carbon dioxide molecules significantly decrease the fracture toughness of the ice crystal, making it more fragile. Using enhanced molecular sampling with metadynamics we reconstruct the free energy landscape in varied chemical microenvironments and find that carbon dioxide molecules affect the bonds between water molecules at the crack tip and decrease their strength by altering the dissociation energy of hydrogen bonds. In the context of glacier dynamics our findings may provide a novel viewpoint that could aid in understanding the breakdown and melting of glaciers, suggesting that the chemical composition of the atmosphere can be critical to mediate the large-scale motion of large volumes of ice.

Qin, Zhao; Buehler, Markus J.

2012-11-01

264

RECYCLED CARBON DIOXIDE - THE VETERAN & VERSATILE PESTICIDE  

Microsoft Academic Search

There is a long history of using carbon dioxide (CO2) in the control of stored grain insects. The ancient practice of burying grain and benefiting from the insecticidal effect of the respired CO2 has advanced to other pesticide applications. ? Anon (1917) reported CO2 the \\

R. F. Ryan

265

Diffusion of propylbenzene (1); carbon dioxide (2)  

NASA Astrophysics Data System (ADS)

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) propylbenzene; (2) carbon dioxide

Winkelmann, J.

266

Carbon dioxide emissions and global GDP  

Microsoft Academic Search

A positive relationship between carbon dioxide emissions, the most important greenhouse gas (GHG) implicated in global warming, and GDP is shown in this paper, examining per capita income and CO2 emissions of 137 countries across 21 years. It also appears that as per capita incomes accelerate across countries emissions increases, for the most part, tend to decelerate. It could be

Michael Tucker

1995-01-01

267

Can the carbon dioxide problem be resolved  

Microsoft Academic Search

The combustion of fossil fuels increases atmospheric levels of carbon dioxide (COâ). This may cause a long-term warming of the atmosphere. Solutions to the COâ problem are particularly difficult because adverse effects will be felt by future generations, but remedial action and sacrifices must be made by present generations. Decisions regarding the problem which affect both the immediate and long-range

Lemons

1984-01-01

268

Acid sorption regeneration process using carbon dioxide  

US Patent & Trademark Office Database

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

2001-11-13

269

Carbon dioxide embolism treated with hyperbaric oxygen.  

PubMed

We report a case of suspected carbon dioxide embolism occurring during laparoscopy. Among the sequelae was neurological dysfunction felt to be secondary to paradoxical embolization. The patient was treated with hyperbaric oxygen therapy. Hyperbaric oxygen should be considered when confronted with a clinically important gas embolism. PMID:2529050

McGrath, B J; Zimmerman, J E; Williams, J F; Parmet, J

1989-09-01

270

Regulating Carbon Dioxide Capture and Storage  

Microsoft Academic Search

This essay examines several legal, regulatory and organizational issues that need to be addressed to create an effective regulatory regime for carbon dioxide capture and storage (“CCS”). Legal, regulatory, and organizational issues will need to be resolved for the industrial organization of CO2 transportation and storage, storage safety and integrity issues, and liability. Although there are some gaps in the

M. A. de Figueiredo; H. J. Herzog; P. L. Joskow; K. A. Oye; D. M. Reiner

2007-01-01

271

Biogas, membranes and carbon dioxide capture  

Microsoft Academic Search

Biogas, which consists primarily of methane, can be obtained through the biological transformation of a large variety of organic wastes, and has drawn an increased interest within a framework of renewable energy sources. The use of gas permeation membranes for upgrading biogas (i.e., for removing carbon dioxide and hydrogen sulfide from biomethane) has been abundantly investigated and already displays practical

Eric Favre; Roda Bounaceur; Denis Roizard

2009-01-01

272

Carbon dioxide absorption in glucosamine aqueous solutions  

Microsoft Academic Search

The present paper includes studies related to gas\\/liquid mass transfer process of carbon dioxide in aqueous solutions of glucose and glucosamine. These studies have been carried out employing a cylindrical bubble column, where the gas phase was fed through an only orifice. The absorption process has been characterized taken into account the influence of gas flow-rate and the liquid phase

D. Gómez-Díaz; J. M. Navaza; B. Sanjurjo; L. Vázquez-Orgeira

2006-01-01

273

Supercritical carbon dioxide extraction of cottonseed oil  

Microsoft Academic Search

Supercritical fluid extraction (SFE) using carbon dioxide is a popular technique for oil extraction due to its high extraction efficiency, short extracting time, lower refining requirement and absence of chemical residues or contamination in the extracted oils. In this work, an attempt has been made to extract oil from a local variety of cottonseed using this technique. The effects of

Paramita Bhattacharjee; Rekha S. Singhal; Sudha R. Tiwari

2007-01-01

274

Personal Carbon Dioxide Impact (title provided or enhanced by cataloger)  

NSDL National Science Digital Library

The amount of carbon dioxide in the atmosphere has been increasing for many decades now, mostly due to the burning of fossil fuels by mankind. In this exercise, students will track their daily activities, and and estimate how much carbon dioxide they are responsible for emitting with the use of an online Personal Greenhouse Gas Calculator developed by the U.S. Environmental Protection Agency (EPA). The calculator sums the carbon dioxide produced by driving, electricity use, and waste disposal, and provides an estimate of annual carbon dioxide emissions. It also allows users to see how changes in lifestyle could reduce carbon dioxide emissions. Links to websites with additional information are also provided.

Pratte, John

275

High Levels of Carbon Dioxide Threaten Oyster Survival  

NSDL National Science Digital Library

It has been widely reported that the build up of carbon dioxide (CO2) in the air, which is caused by human behavior, will likely lead to climate change and have major implications for life on earth. But less focus has been given to global warmingÃÂs evil twin, ocean acidification, which occurs when CO2 lowers the pH of water bodies, thus making them more acidic. This lesser known phenomenon may have catastrophic effects on all sea life. Inna Sokolova, associate professor of biology at the University of North Carolina at Charlotte, studies the affect of high carbon dioxide on oyster survival, growth and shell hardness. The results of her research suggest that creatures once thought to be fairly adaptable to changes in the environment, may be in serious trouble.

APS Communications Office (American Physiological Society Communications Office)

2010-08-04

276

Modeling carbon dioxide, pH, and un-ionized ammonia relationships in serial reuse systems  

USGS Publications Warehouse

In serial reuse systems, excretion of metabolic carbon dioxide has a significant impact on ambient pH, carbon dioxide, and un-ionized ammonia concentrations. This impact depends strongly on alkalinity, water flow rate, feeding rate, and loss of carbon dioxide to the atmosphere. A reduction in pH from metabolic carbon dioxide can significantly reduce the un-ionized ammonia concentration and increase the carbon dioxide concentrations compared to those parameters computed from influent pH. The ability to accurately predict pH in serial reuse systems is critical to their design and effective operation. A trial and error solution to the alkalinity-pH system was used to estimate important water quality parameters in serial reuse systems. Transfer of oxygen and carbon dioxide across the air-water interface, at overflow weirs, and impacts of substrate-attached algae and suspended bacteria were modeled. Gas transfer at the weirs was much greater than transfer across the air-water boundary. This simulation model can rapidly estimate influent and effluent concentrations of dissolved oxygen, carbon dioxide, and un-ionized ammonia as a function of water temperature, elevation, water flow, and weir type. The accuracy of the estimates strongly depends on assumed pollutional loading rates and gas transfer at the weirs. The current simulation model is based on mean daily loading rates; the impacts of daily variation loading rates are discussed. Copies of the source code and executable program are available free of charge.

Colt, J.; Watten, B.; Rust, M.

2009-01-01

277

Modeling Carbon Dioxide, pH and Un-Ionized Ammonia Relationships in Serial Reuse Systems  

USGS Publications Warehouse

In serial reuse systems, excretion of metabolic carbon dioxide has a significant impact on ambient pH, carbon dioxide, and un-ionized ammonia concentrations. This impact depends strongly on alkalinity, water flow rate, feeding rate, and loss of carbon dioxide to the atmosphere. A reduction in pH from metabolic carbon dioxide can significantly reduce the un-ionized ammonia concentration and increase the carbon dioxide concentrations compared to those parameters computed from influent pH. The ability to accurately predict pH in serial reuse systems is critical to their design and effective operation. A trial and error solution to the alkalinity–pH system was used to estimate important water quality parameters in serial reuse systems. Transfer of oxygen and carbon dioxide across the air–water interface, at overflow weirs, and impacts of substrate-attached algae and suspended bacteria were modeled. Gas transfer at the weirs was much greater than transfer across the air–water boundary. This simulation model can rapidly estimate influent and effluent concentrations of dissolved oxygen, carbon dioxide, and un-ionized ammonia as a function of water temperature, elevation, water flow, and weir type. The accuracy of the estimates strongly depends on assumed pollutional loading rates and gas transfer at the weirs. The current simulation model is based on mean daily loading rates; the impacts of daily variation loading rates are discussed. Copies of the source code and executable program are available free of charge.

Barnaby J Watten; Rust, Michael; Colt, John

2009-01-01

278

Carbon dioxide transport in crustal magmatic systems  

NASA Astrophysics Data System (ADS)

The volatile chemistry of juvenile volcanic glasses has suggested that shallow-stored crustal magmas often suffer the open-system addition of a carbon-dioxide-rich fluid from below, probably from a mantle-derived basaltic source ("carbon dioxide fluxing"). However, the actual mechanism of such a fluid transport is poorly understood. To constrain the volatile transport mechanism, we formulated this phenomenon as a reactive transport process and clarified the fundamental characteristics of chemical exchange in the system. The model assumes that a carbon-dioxide-rich fluid is introduced into a water-rich rhyolitic magma column from below and ascends at a constant velocity whilst a volatile exchange takes place between the fluid and melt. Two types of exchange modes were examined. One is the equilibrium mode where the volatile exchange is instantaneously achieved at all column depths. The second is the diffusive mode where the volatile exchange is rate limited by diffusion. In the equilibrium mode, the extent of re-equilibration of the entire column is controlled solely by the mass ratio of the integrated fluid to the melt. In the diffusive mode, the extent of re-equilibration is controlled by the Damköhler number, a dimensionless parameter representing the ratio of the advection time to the diffusion time. When the Damköhler number for carbon dioxide exceeds 10, the diffusive exchange becomes indistinguishable from the equilibrium exchange. Both exchange modes produce a negative correlation between the concentrations of carbon dioxide and water in the melt, which cannot be explained by conventional degassing models without significant crystallisation. The fluid emitted from the column as a volcanic gas changes its composition from carbon dioxide rich to water rich, and the emission rate decreases monotonically during fluxing. The simulation enables us to constrain the mechanism of fluid transport. For the melt inclusion data from the Bishop Tuff (Wallace et al., 1999; Anderson et al., 2000), fluid velocity in this magma was estimated to be 10 - 6 -10 - 7 m/s. The corresponding mechanism of fluid transport may include permeable flow with a permeability of ~ 10 - 15 m 2 or a buoyant ascent of individual bubbles with a radius of 4-7 mm.

Yoshimura, Shumpei; Nakamura, Michihiko

2011-07-01

279

Seasonal effects on the air-water carbon dioxide exchange in the Hooghly estuary, NE coast of Bay of Bengal, India.  

PubMed

Monthly variation of CO2 fugacity (fCO2) in surface water and related atmospheric exchanges were measured in the Hooghly estuary which is one of the most important estuaries, since it is fed by one of the world's largest rivers, the Ganges with a flow of 15,646 m3 s-1 (1.6% of the world's combined river flow). Carbon dioxide fluxes averaged over the entire estuary are in the range of -2.78 to 84.4 mmol m-2 d-1. This estuary acts as a sink for CO2 during monsoon months and seasonal variation of its flux is controlled by dilution of seawater by river water. Since the solubility of CO2 and the disassociation of carbonic acid in estuarine water are controlled by temperature and salinity, the observed variations of CO2 fluxes are compared with those predicted from seasonal changes in temperature, salinity and the ratio of gross primary production to community respiration using empirical equations with an explained variability of 55%. PMID:12195998

Mukhopadhyay, S K; Biswas, H; De, T K; Sen, S; Jana, T K

2002-08-01

280

Carbon Dioxide Diffusion inside Leaves  

Microsoft Academic Search

Leaves are beautifully specialized organs that enable plants to intercept light necessary for photosynthesis. The light is dispersed among a large array of chloroplasts that are in close proximity to air and yet not too far from vascular tissue, which supplies water and exports sugars and other metabolites. To control water loss from the leaf, gas exchange occurs through pores

John R. Evans; Susanne von Caemmerer

1996-01-01

281

Carbon dioxide sequestration by direct mineral carbonation with carbonic acid  

SciTech Connect

The Albany Research Center (ARC) of the U.S. Dept. of Energy (DOE) has been conducting a series of mineral carbonation tests at its Albany, Oregon, facility over the past 2 years as part of a Mineral Carbonation Study Program within the DOE. Other participants in this Program include the Los Alamos National Laboratory, Arizona State University, Science Applications International Corporation, and the DOE National Energy Technology Laboratory. The ARC tests have focused on ex-situ mineral carbonation in an aqueous system. The process developed at ARC utilizes a slurry of water mixed with a magnesium silicate mineral, olivine [forsterite end member (Mg2SiO4)], or serpentine [Mg3Si2O5(OH)4]. This slurry is reacted with supercritical carbon dioxide (CO2) to produce magnesite (MgCO3). The CO2 is dissolved in water to form carbonic acid (H2CO3), which dissociates to H+ and HCO3 -. The H+ reacts with the mineral, liberating Mg2+ cations which react with the bicarbonate to form the solid carbonate. The process is designed to simulate the natural serpentinization reaction of ultramafic minerals, and for this reason, these results may also be applicable to in-situ geological sequestration regimes. Results of the baseline tests, conducted on ground products of the natural minerals, have been encouraging. Tests conducted at ambient temperature (22 C) and subcritical CO2 pressures (below 73 atm) resulted in very slow conversion to the carbonate. However, when elevated temperatures and pressures are utilized, coupled with continuous stirring of the slurry and gas dispersion within the water column, significant reaction occurs within much shorter reaction times. Extent of reaction, as measured by the stoichiometric conversion of the silicate mineral (olivine) to the carbonate, is roughly 90% within 24 hours, using distilled water, and a reaction temperature of 185?C and a partial pressure of CO2 (PCO2) of 115 atm. Recent tests using a bicarbonate solution, under identical reaction conditions, have achieved roughly 83% conversion of heat treated serpentine and 84% conversion of olivine to the carbonate in 6 hours. The results from the current studies suggest that reaction kinetics can be improved by pretreatment of the mineral, catalysis of the reaction, or some combination of the two. Future tests are intended to examine a broader pressure/temperature regime, various pretreatment options, as well as other mineral groups.

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

2000-01-01

282

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

Microsoft Academic Search

Sodium based sorbents including sodium carbonate may be used to capture carbon dioxide from flue gas. A relatively concentrated carbon dioxide stream may be recoverable for sequestration when the sorbent is regenerated. Electrobalance tests indicated that sodium carbonate monohydrate was formed in a mixture of helium and water vapor at temperatures below 65 C. Additional compounds may also form, but

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

2001-01-01

283

Carbon dioxide capture from fossil fuel power plants using dolomite  

Microsoft Academic Search

The main objective of this research is to develop a simple and cost effective separation method that captures carbon dioxide from power plant flue gas, as a pure stream that can be stored using regenerable dolomite (calcium magnesium carbonate) as the sorbent. The developed dolomite sorbent was evaluated for carbon dioxide capture capacity using muti-cycle tests of cyclical carbonation\\/calcination experiments

Drupatie Latchman

2010-01-01

284

“ Bacillus hackensackii” sp. nov., a novel carbon dioxide sensitive bacterium isolated from blood culture  

Microsoft Academic Search

An endospore-forming, gram-positive bacillus was isolated from a patient’s blood culture. This bacillus did not grow in the presence of 5% carbon dioxide although it grew well in ambient air at 37°C. Although the organism thus is an aerobic bacterium, its sensitivity to increased carbon dioxide concentration places it in a distinct category of gaseous atmospheric requirement: capnophobic. Based on

Tao Hong; Nueda Heibler; Y. i-Wei Tang

2003-01-01

285

Effect of controlled carbon dioxide on in vitro shoot multiplication in Feronia limonia (L.) Swingle  

Microsoft Academic Search

The effect of controlled carbon dioxide environment on in vitro shoot growth and multiplication in Feronia limonia (a tropical fruit plant, Family- Rutaceae) was studied. Carbon dioxide available in the ambient air of the growth room was\\u000a insufficient for in vitro growth of the shoots alone. Also, the presence of sucrose only as the C-source in the medium (without CO2),

Shailendra Vyas; Sunil Dutta Purohit

2006-01-01

286

Carbon Dioxide Inhalation Induces Dose-Dependent and Age-Related Negative Affectivity  

Microsoft Academic Search

BackgroundCarbon 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 FindingsSixty-four healthy subjects underwent a double inhalation of four mixtures containing respectively 0, 9, 17.5 and 35% CO2 in compressed air, following a double blind, cross-over, randomized design. Affective

Eric J. Griez; Alessandro Colasanti; Rob van Diest; Ewa Salamon; Koen Schruers; Justin Harris

2007-01-01

287

Global energy and carbon dioxide  

SciTech Connect

The relationship between increasing CO/sub 2/ concentrations in the atmosphere and possible major geophysical and biospheric consequences--the so-called greenhouse issue--has been a question of growing popular and scientific concern. The combustion of fossil fuels is currently the major source term in the atmospheric carbon cycle. This link between energy combustion and carbon concentrations means that most CO/sub 2/ questions of interest to policymakers require the ability to say something about future rates of energy use and the fuel mix. The rapid mixing of CO/sub 2/ in the atmosphere requires that the energy analysis be global. Finally, the cumulative and, to the large extent, irreversible nature of the problem requires a long-term perspective. As with any projection, there are inherent uncertainties; but the very long-term nature of the CO/sub 2/ issue make uncertainty a dominant consideration.

Reilly, J.; Edmonds, J.

1985-01-01

288

Climate impact of increasing atmospheric carbon dioxide  

SciTech Connect

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

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

1981-08-28

289

Hydrates of carbon dioxide and methane mixtures  

Microsoft Academic Search

This paper reports on three-phase equilibrium conditions of hydrates (water-rich liquid, hydrate, and vapor) of carbon dioxide and methane binary mixtures that were investigated in the temperature range of 273-288 K and the pressure range of 1.2-11.0 MPa. The vapor-phase concentrations were measured by a gas chromatograph. The results obtained were in good agreement with previous measurements done by researchers

Sanggono Adisasmito; Robert J. Frank; E. Dendy Sloan

1991-01-01

290

Carbon dioxide neutral, integrated biofuel facility  

Microsoft Academic Search

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 CO2 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

E. E. Powell; G. A. Hill

2010-01-01

291

Carbon dioxide balneotherapy and cardiovascular disease  

Microsoft Academic Search

Carbon dioxide (CO2) balneotherapy is a kind of remedy with a wide spectrum of applications which have been used since the Middle Ages. However,\\u000a its potential use as an adjuvant therapeutic option in patients with cardiovascular disease is not yet fully clarified. We\\u000a performed a thorough review of MEDLINE Database, EMBASE, ISI WEB of Knowledge, COCHRANE database and sites funded

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

292

Carbon dioxide sequestration: how much and when?  

Microsoft Academic Search

Carbon dioxide (CO2) sequestration has been proposed as a key component in technological portfolios for managing anthropogenic climate change,\\u000a since it may provide a faster and cheaper route to significant reductions in atmospheric CO2 concentrations than abating CO2 production. However, CO2 sequestration is not a perfect substitute for CO2 abatement because CO2 may leak back into the atmosphere (thus imposing

Klaus Keller; David McInerney; David F. Bradford

2008-01-01

293

Solubility of triacylglycerols in supercritical carbon dioxide  

Microsoft Academic Search

The solubility of refined corn and sunflower seed oils, babassu (Attalea funifera) and ucuuba (Virola sebifera) fats in supercritical carbon dioxide (SC-CO2) were measured in a temperature range from 40 to 80°C and pressure between 200 and 350bar. Under working conditions, the values of solubility showed retrograde behavior. Experimental SC-CO2 solubility data were collected from the literature for the following

B. M. C. Soares; F. M. C. Gamarra; L. C. Paviani; L. A. G. Gonçalves; F. A. Cabral

2007-01-01

294

The direct carbon dioxide effect on plants  

Microsoft Academic Search

Carbon dioxide may affect plants by changing the climate, but it can have another more subtle and quite separate influence,\\u000a through its direct effects on plant physiology. Since CO2 is fundamental to photosynthesis, it makes sense that increasing the amount of CO2 in the atmosphere will tend to allow plants to photosynthesize faster. This then is one-half of the direct

Jonathan Adams

295

Improved immobilized carbon dioxide capture sorbents  

Microsoft Academic Search

The capture of carbon dioxide from simulated flue gas streams has been achieved by using immobilized and aminated-SBA-15 solid sorbents. SBA-15, a mesoporous silica material with a uniform pore size of 21 nm and a surface area of 200?230 m2\\/g. The solid sorbents prepared in this study exhibit similar or improved capacities relative to those already used to control CO2

M. L. Gray; Y. Soong; K. J. Champagne; H. Pennline; J. P. Baltrus; R. W. Stevens Jr.; R. Khatri; S. S. C. Chuang; T. Filburn

2005-01-01

296

Carbon dioxide capture with concentrated, aqueous piperazine  

Microsoft Academic Search

Concentrated, aqueous piperazine (PZ) has been investigated as a novel amine solvent for carbon dioxide (CO2) absorption. The CO2 absorption rate of aqueous PZ is more than double that of 7m MEA and the amine volatility at 40°C ranges from 11 to 21ppm. Thermal degradation is negligible in concentrated, aqueous PZ up to a temperature of 150°C, a significant advantage

Stephanie A. Freeman; Ross Dugas; David H. Van Wagener; Thu Nguyen; Gary T. Rochelle

2010-01-01

297

Carbon dioxide absorption kinetics in potassium threonate  

Microsoft Academic Search

The absorption of carbon dioxide in potassium threonate aqueous solutions is studied at concentrations ranging from 0.1 to 3M and temperatures from 293 to 313K. This study includes experimental density, viscosity, solubility of N2O and absorption kinetics of CO2 (using a stirred cell reactor) data obtained for the various potassium threonate solutions. The diffusion coefficients of CO2 and potassium threonate

A. F. Portugal; F. D. Magalhães; A. Mendes

2008-01-01

298

Solvent selection for carbon dioxide absorption  

Microsoft Academic Search

Carbon dioxide absorption potentials of selected solvents were assessed by absorption at 40 ?C up to 9.5kPa CO2 partial pressure and desorption at 80 ?C down to 1.0 kPa CO2 partial pressure and compared with monoethanolamine (MEA). Results showed that cyclic capacity of MEA in mol CO2\\/molamine decreases with increase in concentration while its CO2 removal per cycle increases with concentration. Sarcosine neutralized with

Ugochukwu E. Aronu; Hallvard F. Svendsen; Karl Anders Hoff; Olav Juliussen

2009-01-01

299

Solubilities of phenols in supercritical carbon dioxide  

SciTech Connect

Equilibrium solubilities of pure anthracene at 50 C, 1-naphthol at 35, 45, and 55 C, and hydroquinone at 35 and 45 C in supercritical carbon dioxide over a pressure range of about 85--300 bar have been measured using a supercritical fluid extractor coupled with an external high-pressure liquid chromatographer. The solubility results, along with those for other phenols reported in the literature, are correlated with the translated-modified Peng Robinson equation of state.

Coutsikos, P.; Magoulas, K.; Tassios, D. [National Technical Univ. of Athens (Greece)

1995-07-01

300

Single-Breath Continuous Carbon Dioxide Analysis  

Microsoft Academic Search

MEASUREMENTS of inequalities in alveolar ventilation and of physiological dead space give an estimate of the under-ventilated and under-perfused volumes of diseased lungs. Comroe and Fowler1 described the use of a nitrogen meter to detect uneven alveolar ventilation during a single expiration. Dubois et al.2 showed how the physiological dead space could be assessed by measuring the carbon dioxide content

L. Feinmann; G. L. LEATHART; G. B. PENDLENTON

1955-01-01

301

Reduction of carbon dioxide on modified glassy carbon electrodes  

SciTech Connect

Carbon dioxide in the atmosphere gives an important contribution to environmental pollution due to the progressive increase of its production everywhere from many sources. It is believed now that the capacity of the biosphere, due to absorption and transformation of CO{sub 2}, has been considerably exceeded and many attempts to overcome this problem by different ways, have been successful. Electrochemical reduction seems to be an appropriate route for carbon dioxide consumption and its transformation to useful compounds. Electrochemical reduction of carbon dioxide on glassy carbon (GC) was studied by applying different potential regimes and monitoring the effect of the electrode surface conditioning, as well as the nature of supporting electrolyte, upon the nature of the reaction. In the case of constant potential electrolyses, a rapid decay of the cathodic current was observed, while application of a suitable pulse program to the working electrode, in addition to the ultrasonic cleaning of the surface, allowed completion of the reaction without premature current downfall. Modification of the electrode surface, by applying potential pulses, caused a decrease of the reduction potential of CO{sub 2} on glassy carbon. High yields in carbon monoxide and methanol were obtained in these media, with the highest value obtained for methanol in sodium chloride and carbon monoxide in ammonium oxalate.

Hernandez, R.M.; Marquez, J.; Marquez, O.P.; Choy, M.; Ovalles, C.; Garcia, J.J.; Scharifker, B.

1999-11-01

302

Toward Carbon Dioxide Vapor-Pressure Thermometer  

NASA Astrophysics Data System (ADS)

The Temperature Group Laboratory of the National Metrology Institute of Turkey (TUBITAK UME) has realized the scale in the range from the argon triple point (83.8058 K) to the copper freezing point (1357.77 K) and also constructed the International Temperature Scale of 1990 (ITS-90) defining fixed points (Preston-Thomas, Metrologia 27, 3 (1990)). The scale is realized in the low-temperature sub-range by interpolation between the triple points of water, mercury, and argon. The calibration of thermometers below the temperature of the triple point of mercury requires the realization of the argon triple point. Since calibration laboratories are asking for references down to -60 °C, a triple point of carbon dioxide (CO2) gives this opportunity to be used as a secondary fixed point. Another aim of this work is to study the ability of CO2 vapor pressure to realize a vapor-pressure thermometer for covering the range from 216 K up to room temperature. This realization is intended to provide an approximation of the international temperature scale in this temperature range. The vapor-pressure thermometer is intended to be assessed by using the triple point of carbon dioxide and by measuring the pressure values at the temperatures of the triple points of mercury and water. Realization of the triple-point temperature of carbon dioxide and the development of the vapor-pressure thermometer will be investigated and presented in this article.

Dogan, A. Kartal; Bonnier, G.; Uytun, A.; Kocas, I.; Durgut, Y.

2011-12-01

303

Extraction of pharmaceuticals using pressurised carbon dioxide.  

PubMed

This paper reviews the applications of super- and sub-critical carbon dioxide for the extraction of pharmaceuticals from various matrices. The matrices covered are divided into the following types: animal feed, formulations, biological and miscellaneous, with various sub-divisions as appropriate. The polar nature of most pharmaceuticals often precludes the use of carbon dioxide only, so it is common to find the addition of a more polar solvent, as modifier. As the majority of sample types covered are solid, little if any pre-treatment is required, with the exception of grinding, prior to insertion in the sample extraction cell. For liquid-type matrices, sample pre-treatment is the normal. Often this may involve adsorption on an inert support e.g. Celite or diatomaceous earth, or immobilisation on a functionalised silica surface, e.g. C18. The later may take the form of a solid phase extraction cartridge or disk. An attempt has also been made to sample from liquid matrices directly using a modified extraction cell. The variety of sample types, matrices and analyte polarity places stringent requirements on the use of pressurised carbon dioxide. Its potential for effective recovery is examined in this review. PMID:9160253

Dean, J R; Khundker, S

1997-04-01

304

Carbon dioxide in Arctic and subarctic regions  

SciTech Connect

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.

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

1981-03-01

305

Fluid Mechanical Modelling of Carbon Dioxide Sequestration  

NASA Astrophysics Data System (ADS)

The flow of supercritical carbon dioxide against an impermeable caprock will be considered from a theoretical and experimental point of view. A series of fundamental problems will be presented, along with some laboratory simulations. It will be shown that in the simplest case, when the caprock is totally impermeable and horizontal, with viscosity differences between the supercritical carbon dioxide and the fluid into which it is intruding neglected, the radius of the spreading of carbon dioxide increases like the square root of time. We will then consider the influence of a sloping caprock, where for time short compared to some critical time, ?c, the spreading pool is close to axisymmetric, while for times very much greater than ?c it is approximately three times larger in the upslope than cross-slope direction. For typical geological conditions, ?c can vary from between days and years, and hence the observed shape will depend on details at the injection site. A discussion of the effects of different viscosities of the intruding and intruded fluid will be presented and the important non- dimensional physical parameters outlined. The talk will conclude with a discussion of very recent research on the effects of heterogeneous porosity in the ambient and an application of the results to the analysis of the observations at Sleipner. The talk will be illustrated by colour movie sequences of experiments and a real desk- top experiment.

Huppert, H. E.

2007-12-01

306

Bench-to-bedside review: Carbon dioxide  

PubMed Central

Carbon dioxide is a waste product of aerobic cellular respiration in all aerobic life forms. PaCO2 represents the balance between the carbon dioxide produced and that eliminated. Hypocapnia remains a common - and generally underappreciated - component of many disease states, including early asthma, high-altitude pulmonary edema, and acute lung injury. Induction of hypocapnia remains a common, if controversial, practice in both adults and children with acute brain injury. In contrast, hypercapnia has traditionally been avoided in order to keep parameters normal. More recently, advances in our understanding of the role of excessive tidal volume has prompted clinicians to use ventilation strategies that result in hypercapnia. Consequently, hypercapnia has become increasingly prevalent in the critically ill patient. Hypercapnia may play a beneficial role in the pathogenesis of inflammation and tissue injury, but may hinder the host response to sepsis and reduce repair. In contrast, hypocapnia may be a pathogenic entity in the setting of critical illness. The present paper reviews the current clinical status of low and high PaCO2 in the critically ill patient, discusses the insights gained to date from studies of carbon dioxide, identifies key concerns regarding hypocapnia and hypercapnia, and considers the potential clinical implications for the management of patients with acute lung injury.

2010-01-01

307

Carbon dioxide equilibria and their applications  

SciTech Connect

Carbon dioxide, bicarbonate ion, and carbonate ion comprise the most important acid-base system in natural waters, and the equilibria between them regulate the pH of seawater, as well as most rainwater, stream water, river water, and groundwater. Carbon Dioxide Equilibria and Their Applications provides a clear, compact presentation of this topic, which is central to geochemistry and environmental engineering. It emphasizes a rigorous mathematical and thermodynamic basis for calculations and their application to realistic problems. The book's first four chapters present the basic equations, mathematical techniques for visualizing and manipulating them, and data on equilibrium constants and activity coefficients. These are presented in the general context of acid-base titration and solubility of CaCO[sub 3]. The remaining chapters show how these concepts and techniques are applied to geochemistry and oceanography, in addition to their applications to water conditioning. Specific topics discussed include acid rain, freshwater, seawater, carbonate sediments in the deep oceans, the effects of increased atmospheric CO[sub 2] on the oceans, estuarine waters, brines, hydrothermal CO[sub 2] on the oceans, estuarine waters, brines, hydrothermal solutions, pH adjustment, prediction of calcium carbonate saturation, corrosion inhibition, and water softening.

Butler, J.M. (Harvard Univ., Cambridge, MA (United States))

1992-01-01

308

Diffuse volcanic emissions of carbon dioxide from Vulcano Island, Italy.  

PubMed

RECENT investigations on Mount Etna (Sicily)(1-3) have revealed that volcanoes may release abundant carbon dioxide not only from their active craters, but also from their flanks, as diffuse soil emanations. Here we present analyses of soil gases and air in water wells on Vulcano Island which provide further evidence of such lateral degassing. Nearly pure carbon dioxide, enriched in helium and radon, escapes from the slopes of the Fossa active cone, adding a total output of 30 tonnes per day to the fumarolic crater discharge ( 180 tonnes CO(2) per day). This emanation has similar He/CO(2) and (13)C/(12)C ratios to those of the crater fumaroles (300%ndash;500 degrees C) and therefore a similar volcanic origin. Gases rich in carbon dioxide also escape at sea level along the isthmus between the Fossa and Vulcanello volcanic cones, but their depletion in both He and (13)C suggests a distinct source. Diffuse volcanic gas emanations, once their genetic link with central fumarole degassing has been demonstrated, can be used for continuous volcano monitoring, at safe distances from active craters. Such monitoring has been initiated at Vulcano, where soil and well emanations of nearly pure CO(2) themselves represent a threat to the local population. PMID:18278024

Baubron, J C; Allard, P; Toutain, J P

1990-03-01

309

Method of immobilizing carbon dioxide from gas streams  

DOEpatents

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

Holladay, David W. (Knoxville, TN); Haag, Gary L. (Oliver Springs, TN)

1979-01-01

310

The fate of carbon in grasslands under carbon dioxide enrichment  

Microsoft Academic Search

The concentration of carbon dioxide (CO2) in the Earth's atmosphere is rising rapidly, with the potential to alter many ecosystem processes. Elevated CO2 often stimulates photosynthesis, creating the possibility that the terrestrial biosphere will sequester carbon in response to rising atmospheric CO2 concentration, partly offsetting emissions from fossil-fuel combustion, cement manufacture, and deforestation,. However, the responses of intact ecosystems to

Bruce A. Hungate; Elisabeth A. Holland; Robert B. Jackson; F. Stuart Chapin; Harold A. Mooney; Christopher B. Field

1997-01-01

311

Chemical Recycling of Carbon Dioxide to Methanol and Dimethyl Ether: From Greenhouse Gas to Renewable, Environmentally Carbon Neutral Fuels and Synthetic Hydrocarbons  

Microsoft Academic Search

Nature's photosynthesis uses the sun's energy with chlorophyll in plants as a catalyst to recycle carbon dioxide and water into new plant life. Only given sufficient geological time can new fossil fuels be formed naturally. In contrast, chemical recycling of carbon dioxide from natural and industrial sources as well as varied human activities or even from the air itself to

George A. Olah; Alain Goeppert; G. K. Surya Prakash

2009-01-01

312

Changes in Strawberry Anthocyanins and Other Polyphenols in Response to Carbon Dioxide Treatments  

Microsoft Academic Search

Carbon dioxide-enriched atmospheres are used to reduce the incidence and severity of decay and to extend the postharvest life of strawberries. The influence of CO2 on the postharvest quality parameters of strawberries, particularly the stability of anthocyanins and other phenolic compounds, was investigated. Freshly harvested strawberries were placed in jars ventilated continuously with air or air enriched with 10%, 20%,

Maria I. Gil; Deirdre M. Holcroft; Adel A. Kader

1997-01-01

313

Evaluating Life Cycle Carbon Dioxide Emission from Alternative Inter-regional High Speed Passenger Transport Systems  

Microsoft Academic Search

The importance of reducing carbon dioxide (CO2) emission from transport activities from long-distance and high- demand sections is recognized especially in developed countries. This study aims to compare CO2 emission from Shinkansen high speed railway with emissions from air transport by employing LCA method. Here it is assumed that only existing airports are used for air transport but Shinkansen is

Naoki SHIBAHARA; Hirokazu KATO; Yoshitsugu HAYASHI

314

Master Index for the Carbon Dioxide Research State-of-the-ART Report Series.  

National Technical Information Service (NTIS)

Four State of the Art (SOA) reports, ''Atmospheric Carbon Dioxide and the Global Carbon Cycle,'' ''Direct Effects of Increasing Carbon Dioxide on Vegetation,'' ''Detecting the Climatic Effects of Increasing Carbon Dioxide,'' and ''Projecting the Climatic ...

M. P. Farrell

1987-01-01

315

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

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

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

2001-07-01

316

Inverse Estimates of Anthropogenic Carbon Dioxide From Ocean Interior Carbon Measurements and Ocean General Circulation Models  

Microsoft Academic Search

The ocean is an important sink for atmospheric carbon dioxide, and the exchange of carbon dioxide between the atmosphere and ocean plays a critical role in determining the spatial distribution of atmospheric carbon dioxide. However, there is still a great deal of uncertainty in both magnitude and regional patterns of anthropogenic uptake associated with estimates of oceanic carbon fluxes. Using

S. E. Mikaloff Fletcher; N. P. Gruber; A. R. Jacobson; K. Caldeira; S. C. Doney; M. Gloor; M. Follows; K. Lindsay; R. Matear; D. Menemenlis; A. Mouchet; J. L. Sarmiento

2003-01-01

317

Carbon dioxide: A substitute for phosgene  

SciTech Connect

One of the many goals of the green chemistry movement is to eliminate the use of phosgene (COCl{sub 2}), an extremely hazardous compound used in many syntheses, including the production of carbamates, organic carbonates, and polymers. One of the most interesting options for eliminating this compound is to replace it with CO{sub 2}. In addition to carbon dioxide`s abundance and benign nature, it has the benefits of recycling carbon and of reducing the amount of CO{sub 2} released into the atmosphere when its use is linked with other processes that emit CO{sub 2}. Several synthetic strategies that do not use phosgene are under development. The authors briefly review the most interesting ones and then expand on the use of CO{sub 2} as a potential building block for organic carbamates, carbonates, and isocyanates. One of these routes, polycarbonate synthesis, is already in industrial-scale operation: PAC Polymers Inc. currently produces CO{sub 2}-epoxide copolymers. The synthesis of carbamates and substituted ureas has been developed, and this process awaits industrial exploitation.

Aresta, M.; Quaranta, E. [Univ. of Bari (Italy)

1997-03-01

318

Rapid setting of portland cement by greenhouse carbon dioxide capture  

SciTech Connect

Following the work by Berger et al. on rapid setting of calcium silicates by carbonation, a method of high-volume capture of CO{sub 2} in portland cement has been developed. Typically, 10--24 wt. % of CO{sub 2} produced by the calcination of calcium carbonate during clinkering, may be captured, and the set cement acquires most of its full strength in less than a day. The approach will have economic advantages in fabrication of precast structures, in emergency development of infrastructure during natural disasters, and in defense applications. Moreover, it will help the cement industry comply with the Clean Air Act of 1990 by sequestering the greenhouse carbon dioxide.

Wagh, A.S.; Singh, D.; Knox, L.J.

1994-04-01

319

The CNG process: Acid gas removal with liquid carbon dioxide  

SciTech Connect

The CNG acid gas removal process has two unique features: the absorption of sulfur-containing compounds and other trace contaminants with liquid carbon dioxide, and the regeneration of pure liquid carbon dioxide by triple-point crystallization. The process is especially suitable for treating gases which contain large amounts of carbon dioxide and much smaller amounts (relative to carbon dioxide) of hydrogen sulfide. Capital and energy costs are lower than conventional solvent processes. Further, products of the CNG process meet stringent purity specifications without undue cost penalties. A process demonstration unit has been constructed and operated to demonstrate the two key steps of the CNG process. Hydrogen sulfide and carbonyl sulfide removal from gas streams with liquid carbon dioxide absorbent to sub-ppm concentrations has been demonstrated. The production of highly purified liquid carbon dioxide (less than 0.1 ppm total contaminant) by triple-point crystallization also has been demonstrated.

Liu, Y.C.; Auyang, L.; Brown, W.R.

1987-01-01

320

Amperometric sensor for carbon dioxide: design, characteristics, and perforance  

SciTech Connect

A new sensor for atmospheric carbon dioxide is described. It is an amperometric device based on a porous electrode in a three-electrode cell and the electrolyte is a copper diamine complex in aqueous potassium chloride. The platinum cathode, held at constant potential, is used to detect the formation of Cu{sup 2+} following the change in the pH of the solution when the sensor is exposed to an atmosphere containing carbon dioxide. The sensor described is designed to monitor carbon dioxide concentrations in the range 0-5%, although with some modifications, other ranges would be possible. The response to a change in the carbon dioxide content of the atmosphere is rapid (about 10s) while the monitored current is strongly (but nonlinearly) dependent on carbon dioxide concentration. Unlike other amperometric devices for carbon dioxide, there is no interference from oxygen although other acid gases would lead to an interfering response.

Evans, J.; Pletcher, D.; Warburton, P.R.G. (The University, Southampton (Enland)); Gibbs, T.K. (Neotronics, Ltd., Herts (England))

1989-03-15

321

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

ERIC Educational Resources Information Center

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

Brewer, Carol A.; Beiswenger, Jane M.

1993-01-01

322

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

Microsoft Academic Search

This report describes research conducted between April 1, 2005 and June 30, 2005 on the use of dry regenerable sorbents for removal of carbon dioxide from flue gas from coal combustion and synthesis gas from coal gasification. Supported sodium carbonate sorbents removed up to 76% of the carbon dioxide from simulated flue gas in a downflow cocurrent flow reactor system,

David A. Green; Thomas Nelson; Brian S. Turk; Paul Box; Weijiong Li; Raghubir P. Gupta

2005-01-01

323

Carbon dioxide utilization in the chemical industry  

SciTech Connect

Carbon dioxide as a raw material for the Chemical Industry is receiving growing attention because: (i) if recovery of CO{sub 2} from flue gases will be implemented, huge amounts of CO{sub 2} will be available; (ii) environmental issues urge to develop new processes/products, avoiding toxic materials. Several uses of CO{sub 2} appear to be responding to both (i) and (ii), i.e. use as a solvent (supplanting organic solvents) use as a building block for carboxylates/carbonates (supplanting phosgene); use as carbon-source in the synthesis of fuels (supplanting CO or coal/hydrocarbons). These options will be evaluated and their potentiality discussed.

Aresta, M.; Quaranta, E.; Tommasi, I. [Univ. of Bari (Italy)

1996-12-31

324

An IBR System to Quantify the Ocean's Carbon Dioxide Budget  

Microsoft Academic Search

\\u000a The interaction of the atmosphere and the ocean has a profound effect on climate, while the uptake by the oceans of a major\\u000a fraction of atmospheric carbon dioxide has a moderating influence. By improving accuracy in the quantification of the ocean’s\\u000a carbon dioxide budget, a more precise estimation can be made of the terrestrial fraction of global carbon dioxide budget

Juan M. Corchado; Emilio S. Corchado; Jim Aiken

2004-01-01

325

Caffeine solubility in supercritical carbon dioxide\\/co-solvent mixtures  

Microsoft Academic Search

In order to assess the effect of co-solvents on the solubility of caffeine in supercritical carbon dioxide, experimental solubility of caffeine in supercritical ethanol–carbon dioxide and isopropanol–carbon dioxide mixed solvents was obtained using a high-pressure semi-continuous flow apparatus. Caffeine solubilities in 5% ethanol\\/95% CO2, 10% ethanol\\/90% CO2 and 5% isopropanol\\/95% CO2 mixed solvents were determined at 323.2 and 343.2K and

Uiram Kopcak; Rahoma Sadeg Mohamed

2005-01-01

326

Carbon dioxide exchange and early old-field succession  

Microsoft Academic Search

Old-field succession is a widespread process active in shaping landscapes in the eastern United States, contributing significantly to the terrestrial sink of atmospheric carbon dioxide, particularly at midlatitudes. However, few studies document ecosystem-scale carbon dioxide exchange during the early years of old-field succession, particularly during the temporal transition from cultivation to abandonment. Rates of carbon dioxide exchange were measured for

Ryan E. Emanuel; John D. Albertson; Howard E. Epstein; Christopher A. Williams

2006-01-01

327

Carbon Dioxide Sequestration and ECBM in the Powder River Basin  

Microsoft Academic Search

Coal seams are both a source of coal bed methane (CBM) and a potential carbon dioxide sink. For sub-bituminous coals like those in the Powder River Basin (PRB), the CO2\\/CH4 adsorption ratio is approximately 10:1, which indicates the significant potential for sequestering carbon dioxide. In addition, injected carbon dioxide would also enhance the production of methane from the coal seam

L. B. Colmenares; M. D. Zoback

2003-01-01

328

Optical Sensors for Carbon Dioxide and Their Applications  

Microsoft Academic Search

There are few analytes in the world as significant as carbon dioxide, the basic chemical feedstock of life. Through green\\u000a plant photosynthesis, carbon dioxide is converted to the fuel and food necessary for the continued existence of most known\\u000a forms of life. In addition carbon dioxide is an indicator of the existence of life and a measure of health via

Andrew Mills

329

Carbon dioxide capture under ambient conditions using 2-chloroethylamine  

Microsoft Academic Search

This is the first case applying 2-haloethylamine to CO2 capture. The prospect of global warming and the urgent need to reduce atmospheric concentration of carbon dioxide has prompted\\u000a actions at many levels. The conventional capture of carbon dioxide is predominantly based on chemical absorption using ethanolamine.\\u000a Recent developments of carbon dioxide capture focus on new materials, such as ionic liquids,

Junhua WangXiqin; Xiqin Zhang; Yun Zhou

330

Carbon dioxide exhalation temporarily increases during electroconvulsive therapy  

Microsoft Academic Search

Electroconvulsive therapy induces hypermetabolism and elevates oxygen and energy demands, while more carbon dioxide is produced\\u000a than usual. The purpose of the present study was to determine the elevated carbon dioxide exhalation and the adequate ventilation\\u000a volume during electroconvulsive threrapy. Carbon dioxide exhalation during an electrically induced seizure was continuously\\u000a monitored by capnography and spirography in 15 patients with endogenous

Shinobu Sakurazawa; Shigeru Saito; Makiko Yamada; Fumio Nishihara; Fumio Goto

2006-01-01

331

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

PubMed

An off-limb scan of Callisto was conducted by the Galileo near-infrared mapping spectrometer to search for a carbon dioxide atmosphere. Airglow in the carbon dioxide nu3 band was observed up to 100 kilometers above the surface and indicates the presence of a tenuous carbon dioxide atmosphere with surface pressure of 7.5 x 10(-12) bar and a temperature of about 150 kelvin, close to the surface temperature. A lifetime on the order of 4 years is suggested, based on photoionization and magnetospheric sweeping. Either the atmosphere is transient and was formed recently or some process is currently supplying carbon dioxide to the atmosphere. PMID:9933159

Carlson, R W

1999-02-01

332

PHOTOCHEMICAL REACTIONS AMONG FORMALDEHYDE, CHLORINE, AND NITROGEN DIOXIDE IN AIR  

EPA Science Inventory

Photochemical reactions among chlorine, nitrogen dioxide, and formaldehyde were studied, using parts-per-million concentrations in 1 atm of air. The reactant mixtures were irradiated by ultraviolet fluorescent lamps and simultaneously analyzed by the Fourier transform infrared te...

333

Asthma, sulfur dioxide, and the Clean Air Act  

SciTech Connect

Laboratory findings on the effects of sulfur dioxide in patients with asthma are related to theories about the mechanisms of bronchial hyperreactivity, an abnormality that may be fundamental to the pathogenesis of asthma and then to questions of national policy on air quality. Work has shown that people with asthma are abnormally sensitive to inhalation of sulfur dioxide and that bronchospasm may develop if they pursue activities that require light exercise while breathing air containing a level of sulfur dioxide permitted by current ambient air-quality standards. The provisions of the Clean Air Act of 1970 require that sensitive groups in the population be protected against adverse health effects, and our data therefore indicate the need for a short-term standard for sulfur dioxide.

Boushey, H.

1982-02-01

334

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

SciTech Connect

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.

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

335

Containment removal from solid waste by supercritical carbon dioxide  

SciTech Connect

Large quantities of solid wastes such as rags, kimwipes, swabs, coveralls, gloves, etc., contaminated with oils, greases and hazardous solvents are generated by industry and the government. If the hazardous components (offs, greases and solvents) could be segregated from the much larger bulk of non-hazardous material, then these solid materials could potentially be handled as sanitary waste, at a significant cost savings. AlliedSignal KCP, a typical DOE manufacturing site, spent several hundred thousand dollars in CY92 for disposal of contaminated solid wastes. Similarly, Naval Air Station North Island, San Diego, also spent several hundred thousand dollars in CY91 for disposal of rags. Under the Department of Energy (DOE)/United States Air Force (USAF) Memorandum of Understanding, the objective of this joint AlliedSignal KCP/Sandia National Laboratories project is to demonstrate the feasibility of using supercritical carbon dioxide (SC-CO{sub 2}) to segregate hazardous oils, greases, and organic solvents from non-hazardous solid waste such as rags, wipes, swabs, coveralls, gloves, etc. Supercritical carbon dioxide possesses many of the characteristics desired in an ``environmentally acceptable`` solvent system. It is nontoxic, inexpensive, and recyclable. Carbon dioxide possesses a moderate critical temperature (31{degrees}C) and pressure (1071 psi). At 37{degrees}C and pressures greater than 2000 psi, the density is greater than 0.8 g/cc. Contaminants dissolved in the supercritical CO{sub 2} solvent are separated out by expansion of the fluid to a subcritical pressure where CO{sub 2} is a gas and the dissolved materials precipitate out (usually as a liquid or solid). The gaseous CO{sub 2} can then be recompressed and recycled.

Smith, H.M.; Olson, R.B. [Allied-Signal Aerospace Co., Kansas City, MO (United States). Kansas City Div.; Adkins, C.L.J.; Russick, E.M. [Sandia National Labs., Albuquerque, NM (United States)

1994-05-01

336

The fate of carbon in grasslands under carbon dioxide enrichment  

NASA Astrophysics Data System (ADS)

The concentration of carbon dioxide (CO2) in the Earth's atmosphere is rising rapidly, with the potential to alter many ecosystem processes. Elevated CO2 often stimulates photosynthesis, creating the possibility that the terrestrial biosphere will sequester carbon in response to rising atmospheric CO2 concentration, partly offsetting emissions from fossil-fuel combustion, cement manufacture, and deforestation,. However, the responses of intact ecosystems to elevated CO2 concentration, particularly the below-ground responses, are not well understood. Here we present an annual budget focusing on below-ground carbon cycling for two grassland ecosystems exposed to elevated CO2 concentrations. Three years of experimental CO2 doubling increased ecosystem carbon uptake, but greatly increased carbon partitioning to rapidly cycling carbon pools below ground. This provides an explanation for the imbalance observed in numerous CO2 experiments, where the carbon increment from increased photosynthesis is greater than the increments in ecosystem carbon stocks. The shift in ecosystem carbon partitioning suggests that elevated CO2 concentration causes a greater increase in carbon cycling than in carbon storage in grasslands.

Hungate, Bruce A.; Holland, Elisabeth A.; Jackson, Robert B.; Chapin, F. Stuart; Mooney, Harold A.; Field, Christopher B.

1997-08-01

337

Searching for clues to ancient carbon dioxide  

SciTech Connect

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

Appenzeller, T.

1993-02-12

338

A Vortex Contactor for Carbon Dioxide Separations  

SciTech Connect

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.

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

2001-05-01

339

Controls on the Time Scale of Carbonate Neutralization of Carbon Dioxide Released to the Atmosphere  

Microsoft Academic Search

Once released to the atmosphere, carbon dioxide is removed on a range of time scales. On the time scale of years to centuries, carbon dioxide removal from the atmosphere is dominated by transport processes within the ocean. On the time scale of hundreds of thousands of years, carbon dioxide removal from the atmosphere is dominated by processes related to the

K. Caldeira; L. Cao

2007-01-01

340

Carbon dioxide research plan. A summary  

SciTech Connect

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

Not Available

1983-11-01

341

Six-fold coordinated carbon dioxide VI  

NASA Astrophysics Data System (ADS)

Under standard conditions, carbon dioxide (CO2) is a simple molecular gas and an important atmospheric constituent, whereas silicon dioxide (SiO2) is a covalent solid, and one of the fundamental minerals of the planet. The remarkable dissimilarity between these two group IV oxides is diminished at higher pressures and temperatures as CO2 transforms to a series of solid phases, from simple molecular to a fully covalent extended-solid V, structurally analogous to SiO2 tridymite. Here, we present the discovery of an extended-solid phase of CO2: a six-fold coordinated stishovite-like phase VI, obtained by isothermal compression of associated CO2-II (refs 1,2) above 50GPa at 530-650K. Together with the previously reported CO2-V (refs 3-5) and a-carbonia, this extended phase indicates a fundamental similarity between CO2 (a prototypical molecular solid) and SiO2 (one of Earth's fundamental building blocks). We present a phase diagram with a limited stability domain for molecular CO2-I, and suggest that the conversion to extended-network solids above 40-50GPa occurs via intermediate phases II (refs 1,2), III (refs 7,8) and IV (refs 9,10). The crystal structure of phase VI suggests strong disorder along the c axis in stishovite-like P42/mnm, with carbon atoms manifesting an average six-fold coordination within the framework of sp3 hybridization.

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

2007-01-01

342

21 CFR 868.1150 - Indwelling blood carbon dioxide partial pressure (PCO2) analyzer.  

Code of Federal Regulations, 2010 CFR

...Indwelling blood carbon dioxide partial pressure (PCO2) analyzer. 868...Indwelling blood carbon dioxide partial pressure (PCO2 ) analyzer. (a...indwelling blood carbon dioxide partial pressure PCO2 analyzer is a...

2010-04-01

343

21 CFR 868.1150 - Indwelling blood carbon dioxide partial pressure (PCO2) analyzer.  

Code of Federal Regulations, 2010 CFR

...Indwelling blood carbon dioxide partial pressure (PCO2) analyzer. 868...Indwelling blood carbon dioxide partial pressure (PCO2 ) analyzer. (a...indwelling blood carbon dioxide partial pressure PCO2 analyzer is a...

2009-04-01

344

40 CFR 180.1049 - Carbon dioxide; exemption from the requirement of a tolerance.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Carbon dioxide; exemption from the requirement...From Tolerances § 180.1049 Carbon dioxide; exemption from the requirement of a tolerance. The insecticide carbon dioxide is exempted from the...

2013-07-01

345

21 CFR 884.1300 - Uterotubal carbon dioxide insufflator and accessories.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Uterotubal carbon dioxide insufflator and accessories...Devices § 884.1300 Uterotubal carbon dioxide insufflator and accessories...Identification. A uterotubal carbon dioxide insufflator and...

2013-04-01

346

21 CFR 868.1150 - Indwelling blood carbon dioxide partial pressure (PCO2) analyzer.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Indwelling blood carbon dioxide partial pressure (PCO2) analyzer...868.1150 Indwelling blood carbon dioxide partial pressure (PCO2 ) analyzer...Identification. An indwelling blood carbon dioxide partial pressure PCO2...

2013-04-01

347

21 CFR 201.161 - Carbon dioxide and certain other gases.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Carbon dioxide and certain other gases. 201.161...LABELING Other Exemptions § 201.161 Carbon dioxide and certain other gases. (a) Carbon dioxide, cyclopropane, ethylene,...

2013-04-01

348

27 CFR 27.42a - Still wines containing carbon dioxide.  

Code of Federal Regulations, 2013 CFR

...false Still wines containing carbon dioxide. 27.42a Section 27.42a...42a Still wines containing carbon dioxide. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

2013-04-01

349

Titrimetric Determination of Carbon Dioxide in a Heterogeneous Sample  

Microsoft Academic Search

A traditional exercise in quantitative analysis is the titration of mixtures of sodium hydroxide, sodium carbonate, and sodium bicarbonate. Often, consumer products are studied. A procedure to analyze the total volume of carbon dioxide bubbles in the candy \\

Craig M. Davis; Matthew C. Mauck

2003-01-01

350

Carbon dioxide sequestration by ex-situ mineral carbonation  

SciTech Connect

The process developed for carbon dioxide sequestration utilizes a slurry of water mixed with olivine- forsterite end member (Mg{sub 2}SiO{sub 4}), which is reacted with supercritical CO{sub 2} to produce magnesite (MgCO{sub 3}). Carbon dioxide is dissolved in water to form carbonic acid, which likely dissociates to H{sup +} and HCO{sub 3}{sup -}. The H{sup +} hydrolyzes the silicate mineral, freeing the cation (Mg{sup 2+}), which reacts with the HCO{sub 3}{sup -} to form the solid carbonate. Results of the baseline tests, conducted on ground products of the natural mineral, have demonstrated that the kinetics of the reaction are slow at ambient temperature (22 degrees C) and subcritical CO{sub 2} pressures (below 7.4 MPa). However, at elevated temperature and pressure, coupled with continuous stirring of the slurry and gas dispersion within the water column, significant conversion to the carbonate occurs. Extent of reaction is roughly 90% within 24 h, at 185 degrees C and partial pressure of CO{sub 2} (P{sub CO{sub 2}}) of 11.6 MPa. Current studies suggest that reaction kinetics can be improved by pretreatment of the mineral, catalysis of the reaction, and/or solution modification. Subsequent tests are intended to examine these options, as well as other mineral groups.

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

2000-01-01

351

Carbon Dioxide Emissions Embodied in International Trade of Goods  

Microsoft Academic Search

Efforts such as the Kyoto Protocol to reduce emissions that may be linked to climate change focus on six greenhouse gases (GHG). Carbon dioxide is by far the largest of these by volume, representing about 80% of the total emissions of these six gases. Almost all carbon dioxide is emitted during the combustion of fossil fuels and OECD countries account

Nadim Ahmad; Andrew Wyckoff

2003-01-01

352

A Tenuous Carbon Dioxide Atmosphere on Jupiter's Moon Callisto  

Microsoft Academic Search

An off-limb scan of Callisto was conducted by the Galileo Near Infrared Mapping Spectrometer to search for a carbon dioxide atmosphere. Airglow in the CO, v,, band was observed up to 100 km above the surface and indicates the presence of a tenuous carbon dioxide atmosphere with surface pressure of 7.5 x 10\\

Robert W. Carlson

1999-01-01

353

Flexible substrates as basis for photocatalytic reduction of carbon dioxide  

Microsoft Academic Search

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

Jacob Jensen; Mette Mikkelsen; Frederik C. Krebs

2011-01-01

354

Atmospheric carbon dioxide concentrations over the past 60 million years  

Microsoft Academic Search

Knowledge of the evolution of atmospheric carbon dioxide concentrations throughout the Earth's history is important for a reconstruction of the links between climate and radiative forcing of the Earth's surface temperatures. Although atmospheric carbon dioxide concentrations in the early Cenozoic era (about 60Myr ago) are widely believed to have been higher than at present, there is disagreement regarding the exact

Paul N. Pearson; Martin R. Palmer

2000-01-01

355

The Origin of Some Natural Carbon Dioxide Gases  

Microsoft Academic Search

Natural carbon dioxide gas issues from vents and springs in sedimentary rocks. Exploratory wells drilled for oil have produced large volumes of carbon dioxide in subsurface. Where these gases are found in quantity, limestones and igneous rocks are in close association and the origin of the gases is thus suggested. Until the advent of the mass spectrometer there was no

Walter B. Lang

1959-01-01

356

Carbon Dioxide, Global Warming, and Michael Crichton's \\\\State of Fear  

Microsoft Academic Search

In his recent novel, State of Fear (HarperCollins, 2004), Michael Crichton ques- tioned the connection between global warming and increasing atmospheric carbon dioxide by pointing out that for 1940-1970, temperatures were de- creasing while atmospheric carbon dioxide was increasing. A reason for this contradiction was given at Interface 2003 (12) where the temperature time series was well modelled by a

Bert W. Rust

357

Combined reactions and separations using ionic liquids and carbon dioxide  

Microsoft Academic Search

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 fast atom-efficient reactions in a homogenous phase as well as instantaneous product recovery in a biphasic

M. C. Kroon

2006-01-01

358

Hepatic injury induced by carbon dioxide pneumoperitoneum in experimental rats  

Microsoft Academic Search

AIM: To observe the hepatic injury induced by carbon dioxide pneumoperitoneum in rats and to explore its potential mechanism. METHODS: Thirty healthy male SD rats were randomly divided into control group (n = 10), 0 h experimental group (n = 10) and 1 h experimental group (n = 10) after sham operation with carbon dioxide pneumoperitoneum. Histological changes in liver

Gui-Sen Xu; He-Nian Liu; Jun Li; Xiao-Ling Wu; Xue-Mei Dai; Ying-Hai Liu

2009-01-01

359

Entrainment process of carbon dioxide in the atmospheric boundary layer  

Microsoft Academic Search

Aircraft and surface measurements of turbulent thermodynamic variables and carbon dioxide (CO2) were taken above a grassland in a convective atmospheric boundary layer. The observations were analyzed to assess the importance of the entrainment process for the distribution and evolution of carbon dioxide in the boundary layer. From the observations we were able to estimate the vertical profiles of the

Jordi Vilà-Guerau de Arellano; Beniamino Gioli; Franco Miglietta; Harm J. J. Jonker; Henk Klein Baltink; Ronald W. A. Hutjes; Albert A. M. Holtslag

2004-01-01

360

Promising flame retardant textile in supercritical carbon dioxide  

Technology Transfer Automated Retrieval System (TEKTRAN)

Since carbon dioxide is non-toxic, non-flammable and cost-effective, supercritical carbon dioxide (scCO2) is widely used in textile dyeing applications. Due to its environmentally benign character, scCO2 is considered in green chemistry as a substitute for organic solvents in chemical reactions. O...

361

Open Nanoporous Morphologies from Polymeric Blends by Carbon Dioxide Foaming  

Microsoft Academic Search

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 during expansion, the glass transition temperature and carbon dioxide solubility of the dense film were examined at various blend compositions. We

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

2002-01-01

362

The Solubility of Carbon Dioxide in Water at Low Pressure  

Microsoft Academic Search

The system carbon dioxide-water is of great scientific and technological importance. Thus, it has been studied often. The literature for the solubility of carbon dioxide in water is vast and interdisciplinary. An exhaustive survey was conducted and approximately 100 experimental investigations were found that reported equilibrium data at pressures below 1 MPa. A model based on Henry’s law was used

John J. Carroll; John D. Slupsky; Alan E. Mather

1991-01-01

363

Herbivore responses to plants grown in enriched carbon dioxide atmospheres  

Microsoft Academic Search

Our initial study of sagebrush and grasshopper responses to elevated and historical carbon dioxide atmospheres is complete and has been accepted for publication. The study on Biomass Allocation Patterns of Defoliated Sagebrush Grown Under Two Levels of Carbon Dioxide has completed and the manuscript has been submitted for publication. We have completed the study of plant growth under two nutrient

Lincoln

1990-01-01

364

Options for the collection and disposal of carbon dioxide  

Microsoft Academic Search

If society should ever decide that unacceptable changes in climate are imminent because of the accumulation of carbon dioxide in the atmosphere from the use of fossil fuels, it may be necessary to collect and dispose of carbon dioxide. At present it appears that such disposal would consume a large fraction of the energy derived from the fossil fuel. To

C. F. Jr. Baes; S. E. Beall; D. W. Lee; G. Marland

1980-01-01

365

Investigating Diffusion and Entropy with Carbon Dioxide-Filled Balloons  

ERIC Educational Resources Information Center

|Fill an ordinary latex balloon with helium gas and you know what to expect. Over the next day or two the volume will decrease noticeably as helium escapes from the balloon. So what happens when a latex balloon is filled with carbon dioxide gas? Surprisingly, carbon dioxide balloons deflate at rates as much as an order of magnitude faster than…

Jadrich, James; Bruxvoort, Crystal

2010-01-01

366

A monitoring and diagnostic expert system for carbon dioxide capture  

Microsoft Academic Search

The research objective is to design and construct a knowledge-based decision support system for monitoring, control and diagnosis of the carbon dioxide capture process, which is a complicated task involving manipulation of sixteen components and their operating parameters. Since manipulation of critical parameter values directly impacts performance of the plant and carbon dioxide capture efficiency, it is important to effectively

Q. Zhou; C. W. Chan; P. Tontiwachiwuthikul

2009-01-01

367

RETROPERITONEOSCOPIC SURGERY IS NOT ASSOCIATED WITH INCREASED CARBON DIOXIDE ABSORPTION  

Microsoft Academic Search

PurposePrevious studies have suggested that retroperitoneal laparoscopy is associated with greater carbon dioxide absorption and related postoperative morbidity, such as subcutaneous emphysema and pneumothorax. We prospectively compared the effects of carbon dioxide absorption during transperitoneal and retroperitoneal laparoscopic renal and adrenal surgery at our institution.

CHRISTOPHER S. NG; INDERBIR S. GILL; GYUNG TAK SUNG; DAVID G. WHALLEY; RUFFIN GRAHAM; DANA SCHWEIZER

1999-01-01

368

Ocean Acidification Consequences of Stabilization of Atmospheric Carbon Dioxide  

Microsoft Academic Search

We investigate ocean chemistry changes that would result from the stabilization of atmospheric carbon dioxide concentrations at different levels. To determine the fate of ocean chemistry after atmospheric carbon dioxide is stabilized, we perform a suite of simulations using the UVic Earth system model in which atmospheric CO2 is stabilized at levels ranging from 280 ppm to 5000 ppm. Atmospheric

L. Cao; K. Caldeira

2007-01-01

369

Irreversible climate change due to carbon dioxide emissions  

Microsoft Academic Search

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

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

2009-01-01

370

40 CFR 89.322 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Carbon dioxide analyzer calibration. 89.322 Section 89.322 Protection...89.322 Carbon dioxide analyzer calibration. (a) Prior to its introduction...after any maintenance which could alter calibration, and bi-monthly thereafter,...

2012-07-01

371

Use of Carbon Dioxide in Enhanced Oil Recovery  

Microsoft Academic Search

Large volumes of oil will remain in U.S. oil reservoirs when standard recovery methods have been completed. Supercritical carbon dioxide can be used to recover part of that remaining oil. If carbon dioxide is dense enough, it extracts hydrocarbons from the oil to make a mixture miscible with crude oil. Such a mixture can recover 95 percent of the oil

F. M. Jr. Orr; J. J. Taber

1984-01-01

372

MODELING MODELING MODELING MODELING CARBON CARBON CARBON CARBON DIOXIDE DIOXIDE DIOXIDE DIOXIDE EMISSIONS EMISSIONS EMISSIONS EMISSIONS WITH WITH WITH WITHA A A A SYSTEM SYSTEM SYSTEM SYSTEM OF OF OF OF DIFFENTIAL DIFFENTIAL DIFFENTIAL DIFFENTIAL EQUATIONS EQUATIONS EQUATIONS EQUATIONS  

Microsoft Academic Search

ABSTRACT ABSTRACT ABSTRACT The object of the present study is to model carbon dioxide emissions data with a system of differential equations. Carbon dioxide emissions, CO2, are one of the key attributable variables in GLOBAL WARMING along with atmospheric temperature. We develop a differential equation for each of six attributable variables that constitute CO2 emissions and a differential system of

Chris P. Tsokos

373

Annual volcanic carbon dioxide emission: An estimate from eruption chronologies  

Microsoft Academic Search

Continuing interest in the effects of carbon dioxide on climate has been promoted by the exponentially increasing anthropogenic production of CO2. Volcanoes are also a major source of carbon dioxide, but their average input to the atmosphere is generally considered minor relative to anthropogenic input. This study examines eruption chronologies to determine a new estimate of the volcanic CO2 input

Steven W. Leavitt

1982-01-01

374

Advances and trends in primary and small secondary batteries with zinc anodes and manganese dioxide and\\/or air cathodes  

Microsoft Academic Search

Incremental improvements continue to be made year by year in the consumer carbon-zinc and alkaline zinc-manganese dioxide cells. In addition, primary and secondary zinc-air cells many with substantial amounts of manganese dioxide in the cathode are becoming more common in consumer use. The gain in the past fifteen years in the carbon zinc cells approaches fifteen percent and that in

Brooke Schumm

2000-01-01

375

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

USGS Publications Warehouse

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 ?eq/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.

Colt, John; Watten, Barnaby; Pfeiffer, Tim

2012-01-01

376

Carbon dioxide absorbent and method of using the same  

DOEpatents

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.

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

377

Grasland Stable Isotope Flux Measurements: Three Isotopomers of Carbon Dioxide Measured by QCL Spectroscopy  

NASA Astrophysics Data System (ADS)

To improve our understanding of greenhouse gas dynamics of managed ecosystems such as grasslands, we not only need to investigate the effects of management (e.g., grass cuts) and weather events (e.g., rainy days) on carbon dioxide fluxes, but also need to increase the time resolution of our measurements. Thus, for the first time, we assessed respiration and assimilation fluxes with high time resolution (5Hz) stable isotope measurements at an intensively managed farmland in Switzerland (Chamau, 400m ASL). Two different methods were used to quantify fluxes of carbon dioxide and associated fluxes of stable carbon isotopes: (1) the flux gradient method, and (2) the eddy covariance method. During a week long intensive measurement campaign, we (1) measured mixing ratios of carbon dioxide isotopomers (12C16O2, 12C16O18O, 13C16O2) with a Quantum Cascade Laser (QCL, Aerodyne Inc.) spectroscope and (2) collected air samples for isotope analyses (13C/12C) and (18O/16O) of carbon dioxide by Isotope Ratio Mass Spectrometry (IRMS, Finnigan) every two hours, concurrently along a height profile (z = 0.05; 0.10; 0.31; 2.15m). In the following week, the QCL setup was used for closed-path eddy covariance flux measurement of the carbon dioxide isotopomers, with the air inlet located next to an open-path Infra Red Gas Analyzers (IRGA, LiCor 7500) used simultaneously for carbon dioxide measurements. During this second week, an area of grass inside the footprint was cut and harvested after several days. The first results of in-field continuous QCL measurements of carbon dioxide mixing ratios and their stable isotopic ratios show good agreement with IRGA measurements and isotope analysis of flask samples by IRMS. Thus, QCL spectroscopy is a very promising tool for stable isotope flux investigations.

Zeeman, M. J.; Tuzson, B.; Eugster, W.; Werner, R. A.; Buchmann, N.; Emmenegger, L.

2007-12-01

378

Does free-air carbon dioxide enrichment affect photochemical energy use by evergreen trees in different seasons? A chlorophyll fluorescence study of mature loblolly pine  

SciTech Connect

Previous studies of the effects of growth at elevated CO{sup 2} on energy partitioning in the photosynthetic apparatus have produced conflicting results. The hypothesis was developed and tested that elevated CO{sub 2} increases photochemical energy use when there is a high demand for assimilates and decreases usage when demand is low. Modulated chlorophyll a fluorescence and leaf gas exchange were measured on needles at the tope of a mature, 12-m loblolly pine (Pinus taeda L.l) forest. Trees were exposed to ambient CO{sub 2} or ambient plus 20 Pa CO{sub 2} using free-air CO{sub 2} enrichment. During April and August, periods of shoot growth, light-saturated photo-synthesis and linear electron transport were increased by elevated CO{sub 2}. In November, when growth had ceased but temperatures were still moderate, CO{sub 2} treatment had no significant effect on linear electron transport. In February, when low temperatures were likely to inhibit translocation, CO{sub 2} treatment caused a significant decrease in linear electron transport. This coincided with a slower recovery of the maximum photosystem II efficiency on transfer of needles to the shade, indicating that growth in elevated CO{sub 2} induced a more persistent photoinhibition. Both the summer increase and the winter decrease in linear electron transport in elevated CO{sub 2} resulted from a change in photochemical quenching, not in the efficiency of energy transfer within the photosystem II antenna. There was no evidence of any effect of CO{sub 2} on photochemical energy sinks other than carbon metabolism. Their results suggest that elevated CO{sub 2} may increase the effects of winter stress on evergreen foliage.

Hymus, G.J.; Ellsworth, D.S.; Baker, N.R.; Long, S.P.

1999-08-01

379

Photobiological hydrogen production and carbon dioxide sequestration  

NASA Astrophysics Data System (ADS)

Photobiological hydrogen production is an alternative to thermochemical and electrolytic technologies with the advantage of carbon dioxide sequestration. However, it suffers from low solar to hydrogen energy conversion efficiency due to limited light transfer, mass transfer, and nutrient medium composition. The present study aims at addressing these limitations and can be divided in three parts: (1) experimental measurements of the radiation characteristics of hydrogen producing and carbon dioxide consuming microorganisms, (2) solar radiation transfer modeling and simulation in photobioreactors, and (3) parametric experiments of photobiological hydrogen production and carbon dioxide sequestration. First, solar radiation transfer in photobioreactors containing microorganisms and bubbles was modeled using the radiative transport equation (RTE) and solved using the modified method of characteristics. The study concluded that Beer-Lambert's law gives inaccurate results and anisotropic scattering must be accounted for to predict the local irradiance inside a photobioreactor. The need for accurate measurement of the complete set of radiation characteristics of microorganisms was established. Then, experimental setup and analysis methods for measuring the complete set of radiation characteristics of microorganisms have been developed and successfully validated experimentally. A database of the radiation characteristics of representative microorganisms have been created including the cyanobacteria Anabaena variabilis, the purple non-sulfur bacteria Rhodobacter sphaeroides and the green algae Chlamydomonas reinhardtii along with its three genetically engineered strains. This enabled, for the first time, quantitative assessment of the effect of genetic engineering on the radiation characteristics of microorganisms. In addition, a parametric experimental study has been performed to model the growth, CO2 consumption, and H 2 production of Anabaena variabilis as functions of irradiance and CO2 concentration. Kinetic models were successfully developed based on the Monod model and on a novel scaling analysis employing the CO2 consumption half-time as the time scale. Finally, the growth and hydrogen production of Anabaena variabilis have been compared in a flat panel photobioreactor using three different nutrient media under otherwise similar conditions. Light to hydrogen energy conversion efficiency for Allen-Arnon medium was superior by a factor of 5.5 to both BG-11 and BG-11o media. This was attributed to the presence of vanadium and larger heterocyst frequency observed in the Allen-Arnon medium.

Berberoglu, Halil

380

Gaseous Polymer Solutions: Solubilities of Polydimethylsiloxane and Polypropylene in Carbon Dioxide and Viscosities of Polydimethylsiloxane in Carbon Dioxide.  

National Technical Information Service (NTIS)

Polydimethylsiloxane is soluble in carbon dioxide in the weight fraction PMDS approx. 0.026 to approx. 0.33, pressure approx. 80 to approx. 450 atm, and 35 to 80C temperature region. Polypropylene is soluble in carbon dioxide in the weight fraction PP app...

J. L. Lundberg M. E. Sikorski

1983-01-01

381

Carbon monoxide in foundry air.  

PubMed

The concentration of carbon monoxide in the air of 67 iron, steel, or copper alloy foundries using sand molding was measured. About 1,100 carbon monoxide determinations were made. High concentrations of carbon monoxide were found in the area around the cupolas and the casting sites in iron foundries. The blood carboxyhemoglobin levels of 145 workers from iron foundries were measured. The carboxyhemoglobin level of 6% was exceeded in 26% of the nonsmokers and in 71% of the smokers. PMID:968463

Virtamo, M; Tossavainen, A

1976-01-01

382

Experimental fractionation of stable carbon isotopes during degassing of carbon dioxide and precipitation of calcite from aqueous solutions  

NASA Astrophysics Data System (ADS)

Processes in the carbonate system of surface waters are in particular sensitive to variations of boundary conditions as, for instance, the partial pressure of carbon dioxide in the atmosphere and the aqueous solution. Examples range from streams, rivers, to coastal marine waters. The flux of carbon dioxide from continental flowing waters was recently included into calculations of the global carbon budget (Butman & Raymond, 2011, Nature Geo.). These solutions, are often supersaturated in carbon dioxide with respect to the atmosphere. The degassing of carbon dioxide is associated with a kinetically controlled fractionation of the stable carbon isotopes, which has to be considered in balancing water-air carbon dioxide fluxes. The degassing process additionally leads to the super-saturation of the aqueous solution with respect to calcium carbonate. Stable isotope fractionation is of particular value to identify and quantify processes at the water-gas phase interface and link these non-equilibrium processes to the formation mechanisms of calcite and the hydrodynamics of surface waters. Experiments were carried out with or without inert N2 gas flow to degas carbon dioxide from initially supersaturated solutions. Natural solutions used are from different stations of the Elbe estuary, the Jade Bay, the backbarrier tidal area of Spiekeroog Island, carbonate springs of Rügen Island, and the Baltic Sea coastline. Results are compared experiments using bottled mineral waters. By following the (physico) chemical changes in the solutions (pH, TA, Ca PHREEQC modeling) it was found, that two evolutionary stages can be differentiated. Reaction progress led to the preferential liberation of carbon dioxide containing the light carbon isotope, following a Rayleigh-type process. After an induction period, where only degassing of carbon dioxide took place, a second stage was observed where calcite began to form from the highly supersaturated solutions. In this stage the carbonate system of the solution was controlled by both, degassing and carbonate precipitation, still leading to an enrichment of the heavier carbon isotope in the residual DIC. The experimental results are evaluated for both periods, and the influence of salinity and pH is extracted. Acknowledgement: Parts of this study were supported by BMBF within the BIOACID project

Müller, K.; Winde, V.; Escher, P.; von Geldern, R.; Böttcher, M. E.

2012-04-01

383

Altitude controls carbon dioxide in boreal lakes  

NASA Astrophysics Data System (ADS)

Organic matter present in lakes, derived either from land-based sources—such as plants, soil, and sediments—or from in situ processes—such as degrading detritus in the water—could be important in the global carbon cycle, and possibly a significant source of the atmospheric carbon dioxide (CO2) budget. The partial pressure of CO2 in surface waters (pCO2) drives the escape of CO2 to the atmosphere. Hence, scientists have long suspected that the relationship between pCO2 and the dissolved organic matter (DOC) in lake waters refects the relative contribution of the environment and in situ processes to the high-latitude carbon budget. Combining measurements of DOC and pCO2 from nearly 200 lakes across Quebec, Canada, with an additional 13 lake-based studies from temperate regions across the northern hemisphere, Lapierre and del Giorgio suggest that on a regional scale the A variety of lakes dominate the boreal landscape of Quebec, Canada. elevation of lakes is one of the strongest controls on the relationship between DOC and pCO2 in boreal lakes.

Bhattacharya, Atreyee

2012-09-01

384

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

Microsoft Academic Search

The objective of this project is to develop a simple, inexpensive process to separate COâ as an essentially pure stream from a fossil fuel combustion system using a regenerable, sodium-based sorbent. The sorbents being investigated in this project are primarily alkali carbonates, and particularly sodium carbonate and potassium carbonate, which are converted to bicarbonates, through reaction with carbon dioxide and

David A. Green; Brian S. Turk; Raghubir P. Gupta; William J. McMichael; Douglas P. Harrison; Ya Liang

2002-01-01

385

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

Microsoft Academic Search

The objective of this project is to develop a simple and inexpensive process to separate COâ as an essentially pure stream from a fossil fuel combustion system using a regenerable sorbent. The sorbents being investigated in this project are primarily alkali carbonates, and particularly sodium carbonate and potassium carbonate, which are converted to bicarbonates through reaction with carbon dioxide and

David A. Green; Brian S. Turk; Jeffrey W. Portzer; Raghubir P. Gupta; William J. McMichael; Ya Liang; Douglas P. Harrison

2002-01-01

386

Assessing Effects of Rising Carbon Dioxide Levels on Ocean Ecosystems  

Microsoft Academic Search

Carbon Productivity Responses to Increased Dissolved Inorganic Carbon Concentrations in Surface Ocean: Exploring the Feasibility of an in Situ Mesoscale Carbon Addition Experiment; Palisades, New York, 23-24 March 2009; To assess the effects of future elevated carbon dioxide (CO2) levels on ocean biogeochemistry and ecosystems, it is desirable to mimic such an environment in nature. A workshop to explore an

Veronica P. Lance

2009-01-01

387

Master index for the carbon dioxide research state-of-the-art report series  

Microsoft Academic Search

Four State of the Art (SOA) reports, ''Atmospheric Carbon Dioxide and the Global Carbon Cycle,'' ''Direct Effects of Increasing Carbon Dioxide on Vegetation,'' ''Detecting the Climatic Effects of Increasing Carbon Dioxide,'' and ''Projecting the Climatic Effects of Increasing Carbon Dioxide,'' and two companion reports, ''Characterization of Information Requirements for Studies of COâ Effects: Water Resources, Agriculture, Fisheries, Forests and Human

1987-01-01

388

Colorimetric and refractometric measurements of carbon dioxide  

NASA Astrophysics Data System (ADS)

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 (?c 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.

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

2011-05-01

389

A weekly cycle in atmospheric carbon dioxide  

NASA Astrophysics Data System (ADS)

We present a new statistic called the ``Mean Symmetrized Residual'' (MSR) for detection and quantification of a weekly cycle in measured daily atmospheric carbon dioxide (CO2). At the Mauna Loa Observatory in Hawaii, we conclude that CO2 concentrations, on average, are significantly lower (0.022 parts per million by volume, ppmv) on weekends (Saturday-Sunday) than during the rest of the week. Over the past twenty-five years, the variation of the mean values of MSR (as a function of day of the week) has been relatively stable. We speculate that the observed weekday/weekend variation in CO2 at Mauna Loa is the result of anthropogenic emissions on Hawaii and nearby sources. We do not detect a weekly cycle in daily CO2 concentration measured at South Pole, Antarctica. This methodology has applicability to a variety of datasets.

Cerveny, Randall S.; Coakley, Kevin J.

2002-01-01

390

Thermodynamical effects during carbon dioxide release  

NASA Astrophysics Data System (ADS)

Pruess [1] investigated the risk of carbon dioxide leakage from shallow storage sites by modeling scenarios. Such a fluid release is associated with mechanical work performed by formation fluid against expansion without taking heat from ambient environment. Understanding of heat related to mechanical work is essential to predict the temperature at the leak. According to the first law of thermodynamics, internal energy of working fluid decreases with an amount which is equivalent to this work hence, working fluid lost its own heat. Such kind of heat loss depends strongly on whether the expansion process is adiabatic or isothermal. Isothermal expansion allows the working fluid to interact thermally with the solid matrix. Adiabatic expansion is an isenthalpic process that takes heat from the working fluid and the ambient environment remains unchanged. This work is part of the CLEAN research project [6]. In this study, thermodynamic effects of mechanical work during eventual carbon dioxide leakage are investigated numerically. In particular, we are interested to detect the temperature at leakage scenarios and its deviation with different thermodynamic processes. Finite element simulation is conducted with a two-dimensional rectangular geometry representing a shallow storage site which bottom was located at -300m below the land surface. A fully saturated porous medium is assumed where the pore space is filled completely with carbon dioxide. Carbon dioxide accumulated in the secondary trap at 30 Bar and 24 °C is allowed to leak from top right point of rectangle with atmospheric pressure. With (i) adiabatic and (ii) isothermal compressibility factors, temperature around leakage area has been calculated which show a significant difference. With some simplification, this study detects leak temperature which is very close with [1]. Temporal evaluation at the leaky area shows that the working fluid temperature can be reduced to -20 °C when the leakage scenario is performed under isothermal expansion. Under adiabatic expansion, further reduction in the working fluid temperature can be expected. The governing equations from mass and energy balance laws of porous media mechanics are used for problem description. Pressure and fluid phase temperature are chosen as the primary variables. Extended ideal gas law is used with super compressibility factor (SCF) to predict real gas density for large range of pressure and temperature [2]. Cubic equation based on Peng-Robinson equation of state was solved analytically for SCF [3]. Real fluid properties, such as dynamic viscosity, thermal conductivity and specific heat capacity used in this study are density and temperature dependent. Analytical expression for the derivatives of SCF with respect to temperature and pressure are used. Subsequently, these derivatives are utilized to define isothermal compressibility, adiabatic compressibility and thermal expansion coefficient for the real gas. These parameters can influence heat loss due to thermodynamic effects significantly. The governing equations are discretized spatially within the Galerkin approach, whereas for the temporal discretization, we adopt generalized single step method [5]. The coupled system of governing equations is solved in a monolithic way with variable time stepping. The numerical module has been implemented within the open source object-oriented finite element code OpenGeoSys [4].

Singh, A. K.; Böttcher, N.; Görke, U.-J.; Kolditz, O.

2012-04-01

391

Demographic change and carbon dioxide emissions.  

PubMed

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. PMID:22784534

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

2012-07-10

392

Carbon Dioxide Sequestration in Geologic Coal Formations  

SciTech Connect

BP Corporation North America, Inc. (BP) currently operates a nitrogen enhanced recovery project for coal bed methane at the Tiffany Field in the San Juan Basin, Colorado. The project is the largest and most significant of its kind wherein gas is injected into a coal seam to recover methane by competitive adsorption and stripping. The Idaho National Engineering and Environmental Laboratory (INEEL) and BP both recognize that this process also holds significant promise for the sequestration of carbon dioxide, a greenhouse gas, while economically enhancing the recovery of methane from coal. BP proposes to conduct a CO2 injection pilot at the tiffany Field to assess CO2 sequestration potential in coal. For its part the INEEL will analyze information from this pilot with the intent to define the Co2 sequestration capacity of coal and its ultimate role in ameliorating the adverse effects of global warming on the nation and the world.

None

2001-09-30

393

The Relationship between End Tidal Carbon Dioxide and Arterial Carbon Dioxide during Controlled Hypotensive Anaesthesia  

Microsoft Academic Search

Objectives: To prospectively assess the magnitude of changes in the arterial-to-end tidal carbon dioxide gradient [P(a-ET)CO2] as well as in the ratio of physiological dead space to tidal volume (Vdphys\\/Vt) during controlled hypotensive anaesthesia, and to evaluate whether or not ventilatory requirements remain unaltered during this procedure. Subjects and Methods: Twelve adult patients with American Society of Anesthesiologists’ physical status

Syed Shujat Ali; Alexander Dubikaitis; Abdul Raheem Al Qattan

2002-01-01

394

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

This report describes research conducted between October 1, 2004 and December 31, 2004 on the use of dry regenerable sorbents for removal of carbon dioxide from flue gas. Two supported sorbents were tested in a bench scale fluidized bed reactor system. The sorbents were prepared by impregnation of sodium carbonate on to an inert support at a commercial catalyst manufacturing facility. One sorbent, tested through five cycles of carbon dioxide sorption in an atmosphere of 3% water vapor and 0.8 to 3% carbon dioxide showed consistent reactivity with sodium carbonate utilization of 7 to 14%. A second, similarly prepared material, showed comparable reactivity in one cycle of testing. Batches of 5 other materials were prepared in laboratory scale quantities (primarily by spray drying). These materials generally have significantly greater surface areas than calcined sodium bicarbonate. Small scale testing showed no significant adsorption of mercury on representative carbon dioxide sorbent materials under expected flue gas conditions.

David A. Green; Brian S. Turk; Jeffrey W. Portzer; Thomas Nelson; Raghubir P. Gupta

2005-01-01

395

Nonequilibrium dynamic modeling of carbon dioxide absorption by partially carbonated ammonia solutions  

Microsoft Academic Search

In this research, a nonequilibrium dynamic stage model has been developed for reactive absorption of carbon dioxide by carbonated ammonia solutions. The model considers mass transfer between gas and liquid phases in both directions employing dynamic film model theory. Experimental data of carbon dioxide reactive absorption by partially carbonated ammonia solution has been used to validate the model. The data

Ahad Ghaemi; Shahrokh Shahhosseini; Mohammad Ghanadi Maragheh

2009-01-01

396

Testing a Regenerative Carbon Dioxide and Moisture Removal Technology  

NASA Astrophysics Data System (ADS)

The National Aeronautics and Space Administration supported the development of a new vacuum-desorbed regenerative carbon dioxide and humidity control technology for use in short duration human spacecraft. The technology was baselined for use in the Orion Crew Exploration Vehicle's Environmental Control and Life Support System (ECLSS). Termed the Carbon Diox-ide And Moisture Removal Amine Swing-bed (CAMRAS), the unit was developed by Hamilton Sundstrand and has undergone extensive testing at Johnson Space Center. The tests were per-formed to evaluate performance characteristics under range of operating conditions and human loads expected in future spacecraft applications, as part of maturation to increase its readiness for flight. Early tests, conducted at nominal atmospheric pressure, used human metabolic sim-ulators to generate loads, with later tests making us of human test subjects. During these tests many different test cases were performed, involving from 1 to 6 test subjects, with different activity profiles (sleep, nominal and exercise). These tests were conducted within the airlock portion of a human rated test chamber sized to simulate the Orion cabin free air volume. More recently, a test was completed that integrated the CAMRAS with a simulated suit loop using prototype umbilicals and was conducted at reduced atmospheric pressure and elevated oxygen levels. This paper will describe the facilities and procedures used to conduct these and future tests, and provide a summary of findings.

Barta, Daniel J.; Button, Amy; Sweterlitsch, Jeffrey; Curley, Suzanne

397

Regional carbon dioxide fluxes from aircraft measurements in southwest France  

NASA Astrophysics Data System (ADS)

In 2007, the CarboEurope-IP Regional Component organised the second edition of the CERES measurement campaign in the southwest of France. This was a follow-up of the initial campaign in 2005. CERES'07 consisted of two intensive observational periods (IOPs), of which one in spring and the other one in summer. During both IOPs, ground stations, tall towers, radiosondes and a number of aircrafts were used, including our own environmental research aircraft (ERA). The ERA is a small aircraft flying at low altitudes and low air speeds, equipped to measure fluxes of carbon dioxide, latent heat and sensible heat using the eddy-correlation technique. In addition, instruments are on board for measuring ground temperature, net radiation and photosynthetically active radiation (PAR). Flux data obtained with the ERA during CERES'07 have been analyzed and will be presented here. In the data analysis, we present regional fluxes of carbon dioxide focussing at seasonal trends in relation to landscape elements. To achieve this, flight tracks were split into homogeneous segments based on land cover, topography and soil type. During both IOPs, weather conditions were constant. This gives us the possibility to average data in each segment across all flights, though the issue of diurnal variation in surface fluxes and radiation still remains. In short, the analysis strategy on our airborne flux data from CERES'07 will be addressed in this presentation together with its results focussing at drivers for these fluxes at landscape scale.

Vellinga, O. S.; Hutjes, R. W. A.; Elbers, J. A.

2009-04-01

398

Comparison of Several Methods for Nitrogen Dioxide and Sulfur Dioxide in Metro Manila Air  

Microsoft Academic Search

The pollutant gases nitrogen dioxide (NO2) and sulfur dioxide (SO2) are two of the commonly monitored parameters for air quality assessment in the Philippines. In this study, several active and passive sampling methods for the analysis of the two gases were tested. Of the methods for NO2 first tested indoors, the NaI sorbent passive sampling method was found most promising

Leni L. Quirit; Karen N. Hernandez; Brian J. Lee

399

The Effect of Atmospheric Carbon Dioxide Elevation on Plant Growth in Freshwater Ecosystems  

Microsoft Academic Search

We developed a dynamic model to investigate the effect of atmospheric carbon dioxide (CO 2) increase on plant growth in freshwater ecosystems. Steady-state simulations were performed to analyze the response of phytoplankton and submerged macrophytes to atmospheric CO 2 elevation from 350 to 700 ppm. We studied various conditions that may affect this response, such as alkalinity, the air–water exchange

Peter Schippers; Jan E. Vermaat; Jeroen de Klein; Wolf M. Mooij

2004-01-01

400

Regional distribution of glutamate in the central nervous system of rat terminated by carbon dioxide euthanasia  

Microsoft Academic Search

Summary Carbon dioxide euthanasia is an established method for the termination of small laboratory animals. It has also been employed by the authors in neurobiological research on the post- mortem glutamate concentration in the structures of rat brains. The following investigations were aimed at optimizing the termination procedure based on the CO 2 saturation rate of the inhaled air. Two

T. Gos; R. Hauser; M. Krzyzanowski

2002-01-01

401

SHORT-TERM EXPOSURE OF ELEVATED CARBON DIOXIDE CONCENTRATIONS ON BROILER GROWTH RESPONSES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Air quality is essential to getting chicks off to a good start. Improvements in poultry house design and construction have reduced heat loss. To conserve fuel usage, growers ventilate less during winter growouts. As a result, carbon dioxide (CO2) concentration often exceeds 3,000 ppm during brood...

402

Heliox Administration During High-Frequency Jet Ventilation Augments Carbon Dioxide Clearance  

Microsoft Academic Search

We report the combined use of heliox and high-frequency jet ventilation to augment carbon dioxide clearance, with a focus on the important technical considerations. Our case is a 5-month old infant with acute respiratory failure associated with gas trapping, hypercarbia, respiratory acidosis, and air leak. Despite maximal conventional ventilation, bronchodilator therapy, cor- ticosteroids, and sedation, the infant continued to demonstrate

Vineet K Gupta; Eva N Grayck

403

Herbivore responses to plants grown in enriched carbon dioxide atmospheres  

SciTech Connect

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

Lincoln, D.E.

1990-05-01

404

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

This report describes research conducted between April 1, 2005 and June 30, 2005 on the use of dry regenerable sorbents for removal of carbon dioxide from flue gas from coal combustion and synthesis gas from coal gasification. Supported sodium carbonate sorbents removed up to 76% of the carbon dioxide from simulated flue gas in a downflow cocurrent flow reactor system, with an approximate 15 second gas-solid contact time. This reaction proceeds at temperatures as low as 25 C. Lithium silicate sorbents remove carbon dioxide from high temperature simulated flue gas and simulated synthesis gas. Both sorbent types can be thermally regenerated and reused. The lithium silicate sorbent was tested in a thermogravimetric analyzer and in a 1-in quartz reactor at atmospheric pressure; tests were also conducted at elevated pressure in a 2-in diameter high temperature high pressure reactor system. The lithium sorbent reacts rapidly with carbon dioxide in flue gas at 350-500 C to absorb about 10% of the sorbent weight, then continues to react at a lower rate. The sorbent can be essentially completely regenerated at temperatures above 600 C and reused. In atmospheric pressure tests with synthesis gas of 10% initial carbon dioxide content, the sorbent removed over 90% of the carbon dioxide. An economic analysis of a downflow absorption process for removal of carbon dioxide from flue gas with a supported sodium carbonate sorbent suggests that a 90% efficient carbon dioxide capture system installed at a 500 MW{sub e} generating plant would have an incremental capital cost of $35 million ($91/kWe, assuming 20 percent for contingencies) and an operating cost of $0.0046/kWh. Assuming capital costs of $1,000/kW for a 500 MWe plant the capital cost of the down flow absorption process represents a less than 10% increase, thus meeting DOE goals as set forth in its Carbon Sequestration Technology Roadmap and Program Plan.

David A. Green; Thomas Nelson; Brian S. Turk; Paul Box; Weijiong Li; Raghubir P. Gupta

2005-07-01

405

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

This report describes research conducted between January 1, 2005 and March 31, 2005 on the use of dry regenerable sorbents for removal of carbon dioxide from flue gas. Engineered sorbents composed of sodium carbonate on a ceramic support were tested in a laboratory fluidized bed reactor system and found to be capable of essentially complete removal of carbon dioxide at 60 C in a short residence time. Upon breakthrough the sorbents can be thermally regenerated to recover essentially all of the absorbed carbon dioxide. An optimized supported sorbent tested in a pilot-scale entrained bed absorber retained its reactivity in multicycle tests and experienced no attrition. Removal of >90% of carbon dioxide in simulated flue gas was achieved in an entrained bed reactor.

David A. Green; Thomas Nelson; Brian S. Turk; Jeffrey W. Portzer; Raghubir P. Gupta

2005-04-01

406

Surface plasmon resonance sensor for dissolved and gaseous carbon dioxide.  

PubMed

We describe a novel kind of sensor for carbon dioxide. It is based on surface plasmon resonance (SPR) and a polymer blend that is capable of fully reversibly binding carbon dioxide. The interaction results in a change in the polarity and refractive index that can be detected via SPR. The sensor responds with high specificity. The method is simple and, unlike previous ones, enables continuous sensing over extended periods of time. It can be applied to sense both dissolved and gaseous carbon dioxide. The limits if detection of gaseous CO(2) is as low as 10 ppm. PMID:23043622

Lang, Thomas; Hirsch, Thomas; Fenzl, Christoph; Brandl, Fabian; Wolfbeis, Otto S

2012-10-18

407

High temperature carbon dioxide separation membrane  

NASA Astrophysics Data System (ADS)

High temperature membranes for CO2 separation can potentially lead to more efficient energy conversion systems and more effective means of CO2 capture in power plants. A novel technology has been successfully demonstrated for the separation of carbon dioxide, CO2, in the temperature range of 600-900°C. The transport of CO2 is accomplished with a dual-ion transport mechanism between carbonate ions in a molten carbonate phase and oxide ions in an oxide conducting ceramic coupled with a surface reaction converting CO2 to CO32- with O2- from an oxide crystal lattice. The transport of such a system was modeled, and an analytical expression was derived for the flux of CO2 in a bulk diffusion limited system. Dual-phase membranes were fabricated by first creating a porous solid oxide structure using tape casting techniques. The structure was engineered to immobilize the molten carbonate phase in the pore space. Membranes comprised of either 8-mol% yttria stabilized zirconia (YSZ) or 10-mol% gadolinia doped ceria (CGO) and a tertiary mixture of alkali metal carbonates (Li2CO 3,Na2CO3,K2CO3) were able to selectively permeate CO2 at temperatures over 600°C. The flux of CO2 across these membranes increased exponentially with temperature, reaching permeabilities of 1.0 x 10-11 mol m -1 s-1 Pa-1 (or permeance of 3.6 x 10 -8 mol m-2 s-1 Pa-1) with YSZ based membranes and 7.0 x 10-12 mol m-1 s-1 Pa-1 (or permeance of 2.3 x 10-8 mol m-2 s-1 Pa-1) with CGO based membranes at 850°C. It was also discovered that alumina, Al2O3, a non-oxide conducting ceramic, was unable to selectively permeate CO2, providing support for the role of an oxide conducting phase in the transport mechanism. Finally, the chemical reactivity between YSZ and CGO with various mixtures of alkali metal carbonates was examined with thermogravimetric (TGA) and x-ray diffraction (XRD) analysis in order to understand the chemical reactivity and how it relates to the performance of these materials as composite, CO 2 selective membranes. It was revealed that a lack of reactivity between electrolyte pairs does not preclude these materials from functional separation membranes, yet irreversible chemistry can negatively impact long-term CO 2 permeance.

Wade, Jennifer Lynn

408

Low Energy, Low Emissions: Sulfur Dioxide; Nitrogen Oxides, and Carbon Dioxide in Western Europe.  

ERIC Educational Resources Information Center

|Links proposed low-energy scenarios for different Western European countries with the amount of pollutants that may result from these scenarios. Sulfur dioxide, nitrogen oxide, and carbon dioxide emissions are calculated for the 10 countries for which low-energy scenarios are available, resulting in reductions of 54%, 37%, and 40%, respectively.…

Alcamo, Joseph; De Vries, Bert

1992-01-01

409

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

SciTech Connect

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.

Aines, Roger D. (Livermore, CA); Bourcier, William L. (Livermore, CA)

2010-11-09

410

Application of genetic algorithm in atmospheric carbon dioxide concentration retrieval  

NASA Astrophysics Data System (ADS)

This paper introduces the basic theory and method of carbon dioxide (CO2) retrieval. The key step is to search for the optimal solution and the random search algorithm Genetic Algorithm (GA) which can effectively avoid the local optimization. We first investigate the basic principles of GA in CO2 retrieval and then design the corresponding encoding and decoding methods as well as the fitness function. This newly-developed GA is further applied to retrieve the atmospheric CO2 concentration using Atmospheric Infrared Sounder (AIRS) observations from January 2006 to December 2008 centered at 20°N, 144°E. Compared to the aircraft measurements, the GA retrieval yields the small root mean square error of 1.13 ppmv and reproduces good results with the observed seasonal cycle.

Li, Jingyao; Shi, Runhe; Gao, Wei

2013-09-01

411

Carbon dioxide reduction at a metal phthalocyanine catalyzed carbon electrode  

SciTech Connect

Metal phthalocyanines (metal = Co, Ni) deposited on carbon electrodes have been found to catalyze the electroreduction of carbon dioxide to formic acid in acid solutions (pH = 3-7). The overpotential for CO/sub 2/ reduction on cobalt phthalocyanine is approximately 200 mV lower than on the best metal cathodes at currents up to 10 mA/cm/sup 2/. The main reaction product in long-term electrolysis is the formate ion at pH>5. Methanol is also produced at lower pH values. The phthalocyanine becomes inactive in the less acid solutions once a fairly negative potential is imposed, probably due to an irreversible reduction of the catalyst.

Kapusta, S.; Hackerman, N.

1984-07-01

412

A new design of equilibrator to monitor carbon dioxide in highly dynamic and turbid environments.  

PubMed

A new design of equilibrator for carbon dioxide monitoring in natural waters is described. It consists in a vertical tube filled with marbles through which water is flowing while equilibrating with a closed air circuit. It offers several advantages compared with classical equilibrators, among which is a fast response time (half-life constant approximately 30 s) and the potential to work in very turbid water. The proposed equilibrator is of particular interest to monitor carbon dioxide in coastal ecosystems, such as estuaries, which are known to be turbid and highly dynamic. Two performance tests and some field results are presented to illustrate the efficiency of the proposed system. PMID:11268856

Frankignoulle, M; Borges, A; Biondo, R

2001-04-01

413

The effect of increased atmospheric carbon dioxide concentration on emissions of nitrous oxide, carbon dioxide and methane from a wheat field in a semi-arid environment in northern China  

Microsoft Academic Search

There are no reports on the effects of elevated carbon dioxide [CO2] on the fluxes of N2O, CO2 and CH4 from semi-arid wheat cropping systems. These three soil gas fluxes were measured using closed chambers under ambient (420 ± 18 ?mol mol?1) and elevated (565 ± 37 ?mol mol?1) at the Free-Air Carbon dioxide Enrichment experimental facility in northern China. Measurements were made over five weeks on a

Shu Kee Lam; Erda Lin; Rob Norton; Deli Chen

2011-01-01

414

Carbon dioxide insufflation attenuates parietal blood flow obstruction in distended colon  

Microsoft Academic Search

Background  Bowel distention after colonoscopy has been considered as a cause of blood flow disturbance. Carbon dioxide (CO2), with its higher absorbability and vasodilating effect, may reduce parietal blood flow disturbance of distended colon when\\u000a used for intraluminal insufflation instead of air. The purpose of this study was to assess parietal blood flow of the colon\\u000a distended with intraluminal air\\/CO2 insufflation.

K. Yasumasa; K. Nakajima; S. Endo; T. Ito; H. Matsuda; T. Nishida

2006-01-01

415

Carbon dioxide euthanasia in rats: oxygen supplementation minimizes signs of agitation and asphyxia  

Microsoft Academic Search

Summary 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 a high flow rate; leiinto which carbon dioxide was streamed

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

1995-01-01

416

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

Microsoft Academic Search

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 such separations and to replace current technologies, which use aqueous solvents to chemically absorb carbon dioxide.

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

2012-01-01

417

Soil respiration in northern forests exposed to elevated atmospheric carbon dioxide and ozone  

Microsoft Academic Search

The aspen free-air CO2 and O3 enrichment (FACTS II–FACE) study in Rhinelander, Wisconsin, USA, is designed to understand the mechanisms by which young northern deciduous forest ecosystems respond to elevated atmospheric carbon dioxide (CO2) and elevated tropospheric ozone (O3) in a replicated, factorial, field experiment. Soil respiration is the second largest flux of carbon (C) in these ecosystems, and the

Kurt Pregitzer; Wendy Loya; Mark Kubiske; Donald Zak

2006-01-01

418

Atmospheric response to deep-sea injections of fossil-fuel carbon dioxide  

Microsoft Academic Search

The possibility of controlling atmospheric carbon dioxide accumulation and attendant climatic effects from fossil-fuel burning by diverting a fraction of the combustion product and injecting it into the deep-ocean, as proposed by Marchetti, is analyzed using an atmosphere\\/mixed layer\\/diffusive deep-ocean model for the carbon cycle. The model includes the nonlinear buffering of CO2 at the air\\/sea interface, and considers the

Martin I. Hoffert; Yeong-Cherng Wey; Andrew J. Callegari; Wallace S. Broecker

1979-01-01

419

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

Microsoft Academic Search

Human activities have caused changes in the chemical composition of the atmosphere: the concentrations of carbon dioxide (CO2), nitrogen dioxide (NO2), and ozone (O3) have increased and are expected to continue increasing in the future. These gases have the potential to alter plant physiological processes, change growth rates, C:N, and carbon storage potential. The responses of tree seedlings to these

A. S. Eller; J. P. Sparks

2008-01-01

420

Glacial\\/interglacial variations in atmospheric carbon dioxide  

Microsoft Academic Search

Twenty years ago, measurements on ice cores showed that the concentration of carbon dioxide in the atmosphere was lower during ice ages than it is today. As yet, there is no broadly accepted explanation for this difference. Current investigations focus on the ocean's ‘biological pump’, the sequestration of carbon in the ocean interior by the rain of organic carbon out

Edward A. Boyle; Daniel M. Sigman

2000-01-01

421

Membranes for separation of carbon dioxide  

DOEpatents

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.

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

422

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

DOEpatents

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.

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

2013-01-29

423

Decorating catalytic palladium nanoparticles on carbon nanotubes in supercritical carbon dioxide  

SciTech Connect

Hydrogen reduction of a Pd(II)-b-diketone precursor in supercritical carbon dioxide produces palladium nanoparticles on multi-walled carbon nanotubes that exhibit promising catalytic properties for hydrogenation of olefins in carbon dioxide as well as electro-reduction of oxygen in fuel cell applications.

Ye, Xiang-Rong; Lin, Yuehe; Wai, C M.

2003-02-25

424

An in Situ Infrared Study of Dimethyl Carbonate Synthesis from Carbon Dioxide and Methanol over Zirconia  

Microsoft Academic Search

The mechanism of dimethyl carbonate (DMC) synthesis from methanol and carbon dioxide over monoclinic zirconia has been investigated using in situ infrared spectroscopy. The dissociative adsorption of methanol occurs more slowly than the adsorption of carbon dioxide, but the species formed from methanol are bound more strongly. On adsorption, the oxygen atom of methanol binds to coordinately unsaturated Zr4+ cations

Kyeong Taek Jung; Alexis T. Bell

2001-01-01

425

Partitioning Carbon Dioxide and Water Vapor Fluxes Using Correlation Analysis  

Technology Transfer Automated Retrieval System (TEKTRAN)

Partitioning of eddy covariance flux measurements is routinely done to quantify the contributions of separate processes to the overall fluxes. Measurements of carbon dioxide fluxes represent the difference between gross ecosystem photosynthesis and total respiration, while measurements of water vapo...

426

46 CFR 76.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2011 CFR

...SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide...or made inaccessible in the event of a fire in any of the spaces protected...designed to preclude an anticipated ambient temperature in excess of 130 degrees F....

2011-10-01

427

46 CFR 95.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2012 CFR

... CARGO AND MISCELLANEOUS VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide...or made inaccessible in the event of a fire in any of the spaces protected...designed to preclude an anticipated ambient temperature in excess of 130 degrees F....

2012-10-01

428

46 CFR 76.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2012 CFR

...SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide...or made inaccessible in the event of a fire in any of the spaces protected...designed to preclude an anticipated ambient temperature in excess of 130 degrees F....

2012-10-01

429

Hiilidioksiditoimikunnan mietintoe. (Report of the carbon dioxide commission).  

National Technical Information Service (NTIS)

The Commission was entrusted with investigating alternative strategies and measures for limiting and reducing the emissions of carbon dioxide and other greenhouse gases. It was to study both technical and structural means of reducing these emissions. The ...

J. Routti

1991-01-01

430

Are Carbon Dioxide Emissions Rising More Rapidly Than Expected.  

National Technical Information Service (NTIS)

At least one recent report and numerous news articles suggest that carbon dioxide (CO2) emissions are rising more rapidly than expected. This contention is often made by comparing recent emissions estimates with the greenhouse gas (GHG) scenarios publishe...

J. Logan J. A. Leggett

2008-01-01

431

Temporal integration in nasal lateralization and nasal detection of carbon dioxide.  

PubMed

Two experiments examined time/concentration trading for the detection of carbon dioxide, an irritant with little or no odor. Experiment 1 employed the nasal lateralization method: subjects attempted to determine which nostril received carbon dioxide and which received pure air when presented simultaneously. Experiment 2 employed a temporal, two-alternative, forced-choice, detection paradigm with monorhinal stimulation. In both experiments, stimulus duration was varied at a number of fixed concentrations to determine the shortest, detectable pulse. Under both conditions, threshold pulse duration decreased as stimulus concentration increased. Power functions with exponents of less than negative one described the data quite well: More than a twofold increase in duration was needed to compensate for a twofold decrease in concentration. Thus, for carbon dioxide, the nasal trigeminal system functions as an imperfect integrator at threshold-level. PMID:14977810

Wise, Paul M; Radil, Tomas; Wysocki, Charles J

2004-02-01

432

Lake Nyos disaster, Cameroon, 1986: the medical effects of large scale emission of carbon dioxide?  

PubMed

Carbon dioxide was blamed for the deaths of around 1700 people in Cameroon, west Africa, in 1986 when a massive release of gas occurred from Lake Nyos, a volcanic crater lake. The clinical findings in 845 survivors seen at or admitted to hospital were compatible with exposure to an asphyxiant gas. Rescuers noted cutaneous erythema and bullae on an unknown proportion of corpses and 161 (19%) survivors treated in hospital; though these lesions were initially believed to be burns from acidic gases, further investigation suggested that they were associated with coma states caused by exposure to carbon dioxide in air. The disaster at Lake Nyos and a similar event at Lake Monoun, Cameroon, two years previously provide new information on the possible medical effects of large scale emissions of carbon dioxide, though the presence of other toxic factors in these gas releases cannot be excluded. PMID:2502283

Baxter, P J; Kapila, M; Mfonfu, D

1989-05-27

433

THE CHLOROPHYLL-CARBON DIOXIDE RATIO DURING PHOTOSYNTHESIS  

PubMed Central

Using a rapid spectrographic method of carbon dioxide measurement previously described by McAlister (1937) further studies on the time course of photosynthesis in the higher plant, wheat, variety Marquis, are herein reported. Of major importance in this work is the discovery of a pick-up of carbon dioxide in darkness immediately following a high rate of photosynthesis (see Figs. 3 and 4). This pick-up is believed to be due to the action of a carbon dioxide-combining intermediate; i.e., the "acceptor molecule" for carbon dioxide in photosynthesis. The conditions under which this phenomenon has so far been observed indicate that the intermediate is formed in relatively large quantities during the actual process of photosynthesis and not before. That the intermediate is chlorophyllous in nature is suggested by a simple stoichiometry of the order of unity that is found to exist between the number of carbon dioxide molecules taken up and the total number of chlorophyll molecules present in the plant. This is in opposition to the idea of a large photosynthetic unit of some 2000 chlorophyll molecules operating together in the reduction of 1 carbon dioxide molecule. Further studies of the induction phase under various conditions of previous dark rest and of carbon dioxide and light limitation are herein described. Employing the simple hypothesis that the number of carbon dioxide molecules not reduced during the induction period (induction loss) gives a measure of the number of elementary photosynthetic cycles unoperative or compensated for during induction together with the experimental fact that this induction loss is of the order of the total number of chlorophyll molecules present, these latter studies also indicate, in a less direct manner, that chlorophyll participates in photosynthesis as an individual molecule and not as part of a very large multimolecular chlorophyll unit. The fast dark reaction lasting about 1 minute (Fig. 7) required to reproduce both (a) the phenomena of induction in carbon dioxide assimilation and (b) the recovery of fluorescence of chlorophyll in leaves in darkness as observed by Franck and Wood (1936), demonstrates a close relationship between the fluorescence of chlorophyll and induction in photosynthesis. The rate of respiration (carbon dioxide production) of the higher plant, wheat, was measured under intense illumination and in the absence of carbon dioxide (to suppress assimilation). This value was found to be identical with the dark respirational rate measured before and after the light period, indicating very positively the absence of any direct effect of light on respiration.

McAlister, E. D.

1939-01-01

434

THE CHLOROPHYLL-CARBON DIOXIDE RATIO DURING PHOTOSYNTHESIS.  

PubMed

Using a rapid spectrographic method of carbon dioxide measurement previously described by McAlister (1937) further studies on the time course of photosynthesis in the higher plant, wheat, variety Marquis, are herein reported. Of major importance in this work is the discovery of a pick-up of carbon dioxide in darkness immediately following a high rate of photosynthesis (see Figs. 3 and 4). This pick-up is believed to be due to the action of a carbon dioxide-combining intermediate; i.e., the "acceptor molecule" for carbon dioxide in photosynthesis. The conditions under which this phenomenon has so far been observed indicate that the intermediate is formed in relatively large quantities during the actual process of photosynthesis and not before. That the intermediate is chlorophyllous in nature is suggested by a simple stoichiometry of the order of unity that is found to exist between the number of carbon dioxide molecules taken up and the total number of chlorophyll molecules present in the plant. This is in opposition to the idea of a large photosynthetic unit of some 2000 chlorophyll molecules operating together in the reduction of 1 carbon dioxide molecule. Further studies of the induction phase under various conditions of previous dark rest and of carbon dioxide and light limitation are herein described. Employing the simple hypothesis that the number of carbon dioxide molecules not reduced during the induction period (induction loss) gives a measure of the number of elementary photosynthetic cycles unoperative or compensated for during induction together with the experimental fact that this induction loss is of the order of the total number of chlorophyll molecules present, these latter studies also indicate, in a less direct manner, that chlorophyll participates in photosynthesis as an individual molecule and not as part of a very large multimolecular chlorophyll unit. The fast dark reaction lasting about 1 minute (Fig. 7) required to reproduce both (a) the phenomena of induction in carbon dioxide assimilation and (b) the recovery of fluorescence of chlorophyll in leaves in darkness as observed by Franck and Wood (1936), demonstrates a close relationship between the fluorescence of chlorophyll and induction in photosynthesis. The rate of respiration (carbon dioxide production) of the higher plant, wheat, was measured under intense illumination and in the absence of carbon dioxide (to suppress assimilation). This value was found to be identical with the dark respirational rate measured before and after the light period, indicating very positively the absence of any direct effect of light on respiration. PMID:19873123

McAlister, E D

1939-05-20

435

Isothermal vapor--liquid equilibrium data for binary systems at high pressures; Carbon dioxide-methanol, carbon dioxide-ethanol, carbon dioxide1-propanol, methaneethanol, methane1-propanol, ethaneethanol, and ethane1-propanol systems  

Microsoft Academic Search

This paper reports an experiment conducted on isothermal vapor-liquid equilibrium data for binary systems at high pressure. Carbon dioxide-methanol, carbon dioxide-ethanol, carbon dioxide-1-propanol, methane-ethanol, methane-1-propanol, ethane-ethanol, and ethane-1-propanol were measured by a new static phase equilibrium apparatus at 313.4 and 333,4 K.

Kazuhiko Suzuki; Haruhusa Sue; Masahiro Itou; Richard L. Smith; Hiroshi Inomata; K. Aria; Shozaburo Saito

1990-01-01

436

Carbon dioxide sequestration by aqueous mineral carbonation of magnesium silicate minerals  

Microsoft Academic Search

The dramatic increase in atmospheric carbon dioxide since the Industrial Revolution has caused concerns about global warming. Fossil-fuel-fired power plants contribute approximately one third of the total human-caused emissions of carbon dioxide. Increased efficiency of these power plants will have a large impact on carbon dioxide emissions, but additional measures will be needed to slow or stop the projected increase

Stephen J. Gerdemann; David C. Dahlin; William K. OConnor; Larry R. Penner

2003-01-01

437

The Carbamate Reaction of Carbon Dioxide with GlycylGlycine  

Microsoft Academic Search

The carbamate equilibrium between carbon dioxide and glycyl-glycine is believed to form a model for the similar, but more complex, equilibria of carbon dioxide with the terminal alpha -NH2 groups of the haemoglobin molecule. In the case of glycyl-glycine the carbamate equilibrium constant, Kc, has been estimated from the fall, after one second, in the concentration of dissolved CO2 when

F. J. W. Roughton; L. Rossi-Bernardi

1966-01-01

438

Mariner 6: Origin of Mars Ionized Carbon Dioxide Ultraviolet Spectrum  

Microsoft Academic Search

The predicted intensities of the ionized carbon dioxide (CO2{}+) emission feature at 2890 angstroms and the Fox-Duffendack-Barker bands are 5.2 and 19.9 kilorayleighs, respectively, for a vertical column. Direct photoionization of carbon dioxide by solar radiation contributes 3.5 and 4.1 kilorayleighs, respectively, and fluorescent scattering by CO2{}+, 1.6 and 15.3 kilorayleighs, respectively. Photoelectron impacts are less important.

A. Dalgarno; T. C. Degges; A. I. Stewart

1970-01-01

439

Mariner 6: origin of Mars ionized carbon dioxide ultraviolet spectrum.  

PubMed

The predicted intensities of the ionized carbon dioxide (CO(2)+) emission feature at 2890 angstroms and the Fox-Duffendack-Barker bands are 5.2 and 19.9 kilorayleighs, respectively, for a vertical column. Direct photoionization of carbon dioxide by solar radiation contributes 3.5 and 4.1 kilorayleighs, respectively, and fluorescent scattering by C0(2)+, 1.6 and 15.3 kilorayleighs, respectively. Photoelectron impacts are less important. PMID:17750345

Dalgarno, A; Degges, T C; Stewart, A I

1970-03-13

440

Detection of aerosolized cells during carbon dioxide laparoscopy  

Microsoft Academic Search

Laparoscopic surgery for malignancy has been complicated by port-site recurrences. The exact mechanism has yet to be defined.\\u000a In vitro studies suggest that carbon dioxide-induced tumor cell aerosolization may play a role. We have attempted to document\\u000a this in a human model. Patients scheduled for elective laparoscopy underwent port placement and abdominal insufflation with\\u000a carbon dioxide. A suction trap was

Sayeed Ikramuddin; Joel Lucas; E. Christopher Ellison; William J. Schirmer; W. Scott Melvin

1998-01-01

441

Continuous supercritical carbon dioxide processing of palm oil  

Microsoft Academic Search

Crude palm oil was processed by continuous supercritical carbon dioxide. The process reduces the contents of free fatty acids,\\u000a monoglycerides and diglycerides, certain triglycerides, and some carotenes. The refined palm oil from the process has less\\u000a than 0.1% free fatty acids, higher carotene content, and low diglycerides. Solubility of palm oil in supercritical carbon\\u000a dioxide increased with pressure. A co-solvent

C. K. Ooi; A. Bhaskar; M. S. Yener; D. Q. Tuan; J. Hsu; S. S. H. Rizvi

1996-01-01

442

Carbon dioxide in the ocean surface: The homogeneous buffer factor  

USGS Publications Warehouse

The amount of carbon dioxide that can be dissolved in surface seawater depends at least partially on the homogeneous buffer factor, which is a mathematical function of the chemical equilibrium conditions among the various dissolved inorganic species. Because these equilibria are well known, the homogeneous buffer factor is well known. Natural spatial variations depend very systematically on sea surface temperatures, and do not contribute significantly to uncertainties in the present or future carbon dioxide budget. Copyright ?? 1979 AAAS.

Sundquist, E. T.; Plummer, L. N.; Wigley, T. M. L.

1979-01-01

443

Decreased hydraulic conductance in plants at elevated carbon dioxide  

Microsoft Academic Search

Previous work indicated that long-term exposure to ele- vated carbon dioxide levels can reduce hydraulic conduc- tance in some species, but the basis of the response was not determined. In this study, hydraulic conductance was measured at concentrations of both 350 and 700 cm3 nT3 carbon dioxide for plants grown at both concentrations, to determine the reversibility of the response.

J. A. Bunce; L. H. Ziska

1998-01-01

444

Sagebrush and grasshopper responses to atmospheric carbon dioxide concentration  

Microsoft Academic Search

Summary  Seed- and clonally-propagated plants of Big Sagebrush (Artemisia tridentata var.tridentata) were grown under atmospheric carbon dioxide regimes of 270, 350 and 650 ?l l?1 and fed toMelanoplus differentialis andM. sanguinipes grasshoppers. Total shrub biomass significantly increased as carbon dioxide levels increased, as did the weight and area\\u000a of individual leaves. Plants grown from seed collected in a single population exhibited

R. H. Johnson; D. E. Lincoln

1990-01-01

445

Investigation of amine amino acid salts for carbon dioxide absorption  

Microsoft Academic Search

The carbon dioxide capture potential of amine amino acid salts (AAAS), formed by mixing equinormal amounts of amino acids; e.g. glycine, ?-alanine and sarcosine, with an organic base; 3-(methylamino)propylamine (MAPA), was assessed by comparison with monoethanolamine (MEA), and with amino acid salt (AAS) from amino acid neutralized with an inorganic base; potassium hydroxide (KOH). Carbon dioxide absorption and desorption experiments

Ugochukwu E. Aronu; Hallvard F. Svendsen; Karl Anders Hoff

2010-01-01

446

Treatment of condylomata acuminata with carbon dioxide laser.  

PubMed

Ten patients with condyloma acuminatum were treated successfully with carbon dioxide laser photocoagulation. There are no side effects, damage to the surrounding tissue is minimal, and, in our experience, the lesions have not recurred. It is particularly useful for lesions which are recalcitrant to other types of therapy. We now initially treat patients who have lesions in the urethral meatus with the carbon dioxide laser. PMID:7189071

Fuselier, H A; McBurney, E I; Brannan, W; Randrup, E R

1980-03-01

447

Annual volcanic carbon dioxide emission: An estimate from eruption chronologies  

Microsoft Academic Search

Continuing interest in the effects of carbon dioxide on climate has been promoted by the exponentially increasing anthropogenic\\u000a production of CO2. Volcanoes are also a major source of carbon dioxide, but their average input to the atmosphere is generally considered minor\\u000a relative to anthropogenic input. This study examines eruption chronologies to determine a new estimate of the volcanic CO2 input

Steven W. Leavitt

1982-01-01

448

A new air electrode based on carbon nanotubes and Ag–MnO 2 for metal air electrochemical cells  

Microsoft Academic Search

A new air electrode using a combination of dual functional silver\\/manganese dioxide catalysts based on single-walled carbon nanotubes (SWNTs) was developed by chemically reducing silver permanganate with hydrazine. The electrode prepared comprises a high-quality carbon nanotube support with a complex of manganese dioxide and silver catalysts. The electrocatalytical activity of the electrode was examined via a variety of electrochemical testing

Guo-Qing Zhang; Xiao-Gang Zhang; Yong-Gang Wang

2004-01-01

449

Biogenic controls on the air-water carbon dioxide exchange in the Sundarban mangrove environment, northeast coast of Bay of Bengal, India  

Microsoft Academic Search

The Sundarban mangrove forest (4,264 km 2 ) constitutes about 3% of the total area of the world mangrove. We measured diurnal and seasonal variations of air-water CO2 exchange in relation to the occurrence of phytoplankton during January-December 2001. Diurnal variations of airflows showed that the minimum and maximum CO2 flux of 216.2 mmol m 22 h 21 and 49.9

H. Biswas; S. K. Mukhopadhyay; T. K. De; S. Sen; T. K. Jana

2004-01-01

450

Capture of carbon dioxide from air and flue gas in the alkylamine-appended metal-organic framework mmen-Mg2(dobpdc).  

PubMed

Two new metal-organic frameworks, M(2)(dobpdc) (M = Zn (1), Mg (2); dobpdc(4-) = 4,4'-dioxido-3,3'-biphenyldicarboxylate), adopting an expanded MOF-74 structure type, were synthesized via solvothermal and microwave methods. Coordinatively unsaturated Mg(2+) cations lining the 18.4-Å-diameter channels of 2 were functionalized with N,N'-dimethylethylenediamine (mmen) to afford Mg(2)(dobpdc)(mmen)(1.6)(H(2)O)(0.4) (mmen-Mg(2)(dobpdc)). This compound displays an exceptional capacity for CO(2) adsorption at low pressures, taking up 2.0 mmol/g (8.1 wt %) at 0.39 mbar and 25 °C, conditions relevant to removal of CO(2) from air, and 3.14 mmol/g (12.1 wt %) at 0.15 bar and 40 °C, conditions relevant to CO(2) capture from flue gas. Dynamic gas adsorption/desorption cycling experiments demonstrate that mmen-Mg(2)(dobpdc) can be regenerated upon repeated exposures to simulated air and flue gas mixtures, with cycling capacities of 1.05 mmol/g (4.4 wt %) after 1 h of exposure to flowing 390 ppm CO(2) in simulated air at 25 °C and 2.52 mmol/g (9.9 wt %) after 15 min of exposure to flowing 15% CO(2) in N(2) at 40 °C. The purity of the CO(2) removed from dry air and flue gas in these processes was estimated to be 96% and 98%, respectively. As a flue gas adsorbent, the regeneration energy was estimated through differential scanning calorimetry experiments to be 2.34 MJ/kg CO(2) adsorbed. Overall, the performance characteristics of mmen-Mg(2)(dobpdc) indicate it to be an exceptional new adsorbent for CO(2) capture, comparing favorably with both amine-grafted silicas and aqueous amine solutions. PMID:22475173

McDonald, Thomas M; Lee, Woo Ram; Mason, Jarad A; Wiers, Brian M; Hong, Chang Seop; Long, Jeffrey R

2012-04-12

451

In situ measurements of carbon dioxide in the winter Arctic vortex and at midlatitudes - An indicator of the 'age' of stratospheric air  

Microsoft Academic Search

New measurements are reported of the vertical CO2 distribution mixing ratio in the lower and middle stratosphere. The annual increase of CO2 content in midstratospheric air is comparable to the temporal CO2 trend in the troposphere, but the stratospheric concentrations lag the tropospheric ones by an average of 5.6 + or - 1.1 yr. This delay time may be interpreted

U. Schmidt; A. Khedim

1991-01-01

452

Carbon dioxide sequestration by direct aqueous mineral carbonation  

SciTech Connect

Carbon dioxide sequestration by an ex-situ, direct aqueous mineral carbonation process has been investigated over the past two years. This process was conceived to minimize the steps in the conversion of gaseous CO2 to a stable solid. This meant combining two separate reactions, mineral dissolution and carbonate precipitation, into a single unit operation. It was recognized that the conditions favorable for one of these reactions could be detrimental to the other. However, the benefits for a combined aqueous process, in process efficiency and ultimately economics, justified the investigation. The process utilizes a slurry of water, dissolved CO2, and a magnesium silicate mineral, such as olivine [forsterite end member (Mg2SiO4)], or serpentine [Mg3Si2O5(OH)4]. These minerals were selected as the reactants of choice for two reasons: (1) significant abundance in nature; and (2) high molar ratio of the alkaline earth oxides (CaO, MgO) within the minerals. Because it is the alkaline earth oxide that combines with CO2 to form the solid carbonate, those minerals with the highest ratio of these oxides are most favored. Optimum results have been achieved using heat pretreated serpentine feed material, sodium bicarbonate and sodium chloride additions to the solution, and high partial pressure of CO2 (PCO2). Specific conditions include: 155?C; PCO2=185 atm; 15% solids. Under these conditions, 78% conversion of the silicate to the carbonate was achieved in 30 minutes. Future studies are intended to investigate various mineral pretreatment options, the carbonation solution characteristics, alternative reactants, scale-up to a continuous process, geochemical modeling, and process economics.

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

2000-01-01

453

Oxygen Isotope Composition of Stratospheric Carbon Dioxide  

NASA Astrophysics Data System (ADS)

In the stratosphere, carbon dioxide gradually obtains an anomalous oxygen isotope enrichment, which generally increases with altitude. This enrichment has been related to transfer of anomalously fractionated oxygen from ozone to CO2 via a short-lived CO3* complex, which CO2 forms with O(1D) produced in the photolysis of ozone, al- though the precise transfer mechanism is still being debated. We present CO2 and O3 isotope measurements from 8 stratospheric balloon flights at two latitudes that provide now a complete oxygen isotope analysis of both gases. The results show an unambigu- ous, very tight correlation between 17O and 18O in CO2, which passes through the tropospheric values at the tropopause. The large ratio 17O/18O of 1.7 shows a faster transfer of 17 O than of 18 O into CO2 and establishes a standard throughout the lower and middle stratosphere. Ozone isotope transfer can now be treated in models with re- liable atmospheric data. Additional laboratory exchange experiments are being carried out to investigate the oxygen transfer process in detail.

Röckmann, T.; Brenninkmeijer, C. A. M.; Assonov, S. S.; Lämmerzahl, P.; Krankowsky, D.; Mauersberger, K.

454

Laser surgery: using the carbon dioxide laser.  

PubMed Central

In 1917 Einstein theorized tha through an atomic process a unique kind of electromagnetic radiation could be produced by stimulated emission. When such radiation is in the optical or infrared spectrum it is termed laser (light amplification by stimulated emission of radiation) light. A laser, a high-intensity light source, emits a nearly parallel electromagnetic beam of energy at a given wavelength that can be captured by a lens and concentrated in the focal spot. The wavelength determines how the laser will be used. The carbon dioxide laser is now successfully employed for some surgical procedures in gynecology, otorhinolaryngology, neurosurgery, and plastic and general surgery. The CO2 laser beam is directed through the viewing system of an operating microscope or through a hand-held laser component. Its basic action in tissue is thermal vaporization; it causes minimal damage to adjacent tissues. Surgeons require special training in the basic methods and techniques of laser surgery, as well as in the safety standards that must be observed. Images FIG. 5

Wright, V. C.

1982-01-01

455

Development of Carbon Dioxide Hermitic Compressor  

NASA Astrophysics Data System (ADS)

Because of global environmental problems, the existing refrigerants are to be replaced with natural refrigerants. CO2 is one of the natural refrigerants and environmentally safe, inflammable and non-toxic refrigerant. Therefore high efficiency compressor that can operate with natural refrigerants, especially CO2, needs to be developed. We developed a prototype CO2 hermetic compressor, which is able to use in carbon dioxide refrigerating systems for practical use. The compressor has two rolling pistons, and it leads to low vibrations, low noise. In additions, two-stage compression with two cylinders is adopted, because pressure difference is too large to compress in one stage. And inner pressure of the shell case is intermediate pressure to minimize gas leakage between compressing rooms and inner space of shell case. Intermediate pressure design enabled to make the compressor smaller in size and lighter in weight. As a result, the compressor achieved high efficiency and high reliability by these technology. We plan to study heat pump water heater, cup vending machine and various applications with CO2 compressor.

Imai, Satoshi; Oda, Atsushi; Ebara, Toshiyuki

456

Carbon dioxide balneotherapy and cardiovascular disease  

NASA Astrophysics Data System (ADS)

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.

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

2011-09-01

457

Carbon dioxide balneotherapy and cardiovascular disease  

NASA Astrophysics Data System (ADS)

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.

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

2010-10-01

458

Rat aversion to isoflurane versus carbon dioxide.  

PubMed

Some experts suggest that sedation of laboratory rodents with isoflurane before euthanasia with carbon dioxide (CO(2)) is a humane alternative to euthanasia with CO(2) alone, but little research has compared aversion with these agents. Albino rats were tested in a light-dark box where they had the choice between remaining in a dark compartment filling with isoflurane or CO(2), or escaping to a lit compartment. Experiment 1 validated the procedure by confirming that rats responded to agent and light intensity. In experiment 2, 9/16 and 0/16 rats remained in the dark compartment until recumbent when initially exposed to isoflurane and CO(2), respectively. In experiment 3, more rats remained in the dark compartment until recumbent during initial (10/16) versus re-exposure (1/16) to isoflurane. These results indicate that initial exposure to CO(2) is more aversive than isoflurane, and that re-exposure to isoflurane is more aversive than initial exposure. We conclude that sedation with isoflurane is a refinement over euthanasia with CO(2) alone for rats that have not been previously exposed to inhalant anaesthetics. PMID:23256183

Wong, Devina; Makowska, I Joanna; Weary, Daniel M

2012-12-19

459

Acute carbon dioxide avoidance in Caenorhabditis elegans.  

PubMed

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

Hallem, Elissa A; Sternberg, Paul W

2008-06-04

460

An optimized molecular potential for carbon dioxide.  

PubMed

An optimized molecular potential model for carbon dioxide is presented in this paper. Utilizing the established techniques of molecular-dynamics and histogram reweighting grand canonical Monte Carlo simulations, this model is demonstrated to show excellent predictability for thermodynamic, transport, and liquid structural properties in a wide temperature-pressure range with remarkable accuracies. The average deviations of this new model from experimental data for the saturated liquid densities, vapor densities, vapor pressures, and heats of vaporization are around 0.1%, 2.3%, 0.7%, and 1.9%, respectively. The calculated critical point is almost pinpointed by the new model. The experimental radial distribution functions ranging from 240.0 to 473.0 K are well reproduced as compared to neutron-diffraction measurements. The predicted self-diffusion coefficients are in good agreement with the nuclear-magnetic-resonance measurements. The previously published potential models for CO2 are also systematically evaluated, and our proposed new model is found to be superior to the previous models in general. PMID:15974754

Zhang, Zhigang; Duan, Zhenhao

2005-06-01

461

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

462

A 400 million year carbon isotope record of pedogenic carbonate: Implications for paleoatmospheric carbon dioxide  

Microsoft Academic Search

A 400 record of atmospheric carbon dioxide levels has been estimated by applying a COâ paleobarometer to a database of 758 analyses of paleosol (fossil soil) carbonates. This database is a compilation of new data and previously published values from the literature. Many new analyses of Mesozoic paleosols are reported, an era poorly represented in the literature. Results indicate that

D. D. Ekart; T. E. Cerling; I. P. Montanez; N. J. Tabor

1999-01-01

463

Dark fixation of carbon dioxide in an agricultural soil  

SciTech Connect

Dark fixation of carbon dioxide was monitored in an agricultural soil in northeast Georgia from December 1981 through December 1982. Carbon fixation, based on the rate of radiolabeled CO/sub 2/ incorporation, varied from 0.2 to 4.8 mg m/sup -2/ h/sup -1/. Stepwise regression analysis indicated that dark fixation was positively correlated with the rate of carbon dioxide evolution and soil temperature and was inversely correlated with irradiance. Total annual dark fixation of carbon was estimated to be 15 g m/sup -2/.

Shimmel, S.M.

1987-07-01

464

Terpolymerization of ethylene, sulfur dioxide and carbon monoxide  

DOEpatents

This invention relates to a high molecular weight terpolymer of ethylene, sulfur dioxide and carbon monoxide stable to 280.degree. C. and containing as little as 36 mol % ethylene and about 41-51 mol % sulfur dioxide; and to the method of producing said terpolymer by irradiation of a liquid and gaseous mixture of ethylene, sulfur dioxide and carbon monoxide by means of Co-60 gamma rays or an electron beam, at a temperature of about 10.degree.-50.degree. C., and at a pressure of about 140 to 680 atmospheres, to initiate polymerization.

Johnson, Richard (Shirley, NY); Steinberg, Meyer (Huntington Station, NY)

1981-01-01

465

Properties of the Spatial-Temporal Distribution of a Non-linear Estimate of Carbon Dioxide Derived from AIRS Hyperspectral Measurements  

NASA Astrophysics Data System (ADS)

Eighteen granules (18 days) of AIRS measurements from Oct 2002 - Jan 2004 over Hawaii were processed and analyzed. Geophysical parameters at cloud free pixels are retrieved with a non- linear radiative transfer formulation. The radiative transfer model for a cloud free atmosphere includes spectral reflection at the lower boundary. A modified UMBC SARTA code is used for atmospheric spectral transmittance calculations. The physical parameters included in the model are: (1) surface emissivity spectrum (13 spectral parameters), (2) surface temperature, (3) atmospheric temperature vertical profile (35 vertical parameters), (4) atmospheric moisture vertical profile (22 vertical parameters), (5) atmospheric ozone vertical profile (17 vertical parameters), (6) atmospheric CO2 vertical profile (16 vertical parameters). In all 104 variables are estimated with each spatial pixel. A solution is derived from minimization of the spatial integral of a weighted absolute difference (measurement - model). Results of geophysical interpretation of AIRS hyperspectral measurements from 18 granules (from Oct 2002 - Jan 2004) show that estimate of vertical CO2 profile provide physically meaningful information at atmospheric layer 150-350 hPa. Observed CO2 fields demonstrate spatial consistency with noticeable horizontal and vertical variations. Temporal (seasonal) variations of the estimated average CO2 concentration at atmospheric layer 150-350 hPa demonstrate excellent correlation with temporal variations of direct CO2 measurements over Hawaii.

Plokhenko, Y.; Menzel, P.; Knuteson, R.; Revercomb, H.; Moeller, S. C.

2008-12-01

466

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

SciTech Connect

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 oilcontaining formations or saline aquifers. The term ?globule? refers to the water or liquid carbon dioxide droplets sheathed with ultrafine particles dispersed in the continuous external medium, liquid CO{sub 2} or H{sub 2}O, respectively. The key to obtaining very small globules is the shear force acting on the two intermixing fluids, and the use of ultrafine stabilizing particles or nanoparticles. We found that using Kenics-type static mixers with a shear rate in the range of 2700 to 9800 s{sup -1} and nanoparticles between 100-300 nm produced globule sizes in the 10 to 20 ?m range. Particle stabilized emulsions with that kind of globule size should easily penetrate oil-bearing formations or saline aquifers where the pore and throat size can be on the order of 50 ?m or larger. Subsequent research focused on creating particle stabilized emulsions that are deemed particularly suitable for Permanent Sequestration of Carbon Dioxide. Based on a survey of the literature an emulsion consisting of 70% by volume of water, 30% by volume of liquid or supercritical carbon dioxide, and 2% by weight of finely pulverized limestone (CaCO{sub 3}) was selected as the most promising agent for permanent sequestration of CO{sub 2}. In order to assure penetration of the emulsion into tight formations of sandstone or other silicate rocks and carbonate or dolomite rock, it is necessary to use an emulsion consisting of the smallest possible globule size. In previous reports we described a high shear static mixer that can create such small globules. In addition to the high shear mixer, it is also necessary that the emulsion stabilizing particles be in the submicron size, preferably in the range of 0.1 to 0.2 ?m (100 to 200 nm) size. We found a commercial source of such pulverized limestone particles, in addition we purchased under this DOE Project a particle grinding apparatus that can provide particles in the desired size range. Additional work focused on attempts to generate particle stabilized emulsions with a flow through, static mixer based apparatus under a variety

Ryan, David; Golomb, Dan; Shi, Guang; Shih, Cherry; Lewczuk, Rob; Miksch, Joshua; Manmode, Rahul; Mulagapati, Srihariraju; Malepati, Chetankurmar

2011-09-30

467

Relationship between arterial carbon dioxide and end-tidal carbon dioxide when a nasal sampling port is used  

Microsoft Academic Search

End-tidal carbon dioxide (ETCO2) values obtained from awake nonintubated patients may prove to be useful in estimating a patient’s ventilatory status. This\\u000a study examined the relationship between arterial carbon dioxide tension (PaCO2) and ETCO2 during the preoperative period in 20 premedicated patients undergoing various surgical procedures. ETCO2 was sampled from a 16-gauge intravenous catheter pierced through one of the two

Stephen E. McNulty; John Roy; Marc Torjman; Joseph L. Seltzer

1990-01-01

468

Impact of cement renders on airborne ozone and carbon dioxide concentrations  

NASA Astrophysics Data System (ADS)

The uptake of pollutants by building surfaces can potentially improve both indoor and outdoor air quality. Cement renders provide a unique opportunity for passive pollutant removal because they can cover large surface areas. This study investigated the passive removal of carbon dioxide and ozone by cement renders having varied binder compositions and curing durations. The results from this study demonstrated shorter curing durations resulted in greater pollutant uptake. However, the use of the supplementary cementitious material, metakaolin, in the cement render increased the carbon dioxide ingress while decreasing the ozone uptake. Therefore, the adaptation of the render composition for the best effective application may result in valuable indoor air quality or carbon savings consequences.

Taylor-Lange, Sarah C.; Juenger, Maria C. G.; Siegel, Jeffrey A.

2013-05-01

469

Effect of Carbon Dioxide on Testing of Susceptibilities of Respiratory Tract Pathogens to Macrolide and Azalide Antimicrobial Agents  

Microsoft Academic Search

The in vitro activities of erythromycin, azithromycin, and clarithromycin against 178 clinical isolates from the lower respiratory tract of patients with chronic obstructive pulmonary disease were determined by an agar dilution method. The plates were incubated in air alone or in 5% carbon dioxide. The MICs measured in air alone were lower for most isolates than those measured in 5%

M. M. JOHNSON; S. L. HILL; LAURA J. V. PIDDOCK

1999-01-01

470

Interaction of Surface Modified Carbon Nanotubes with Supercritical Carbon Dioxide  

NASA Astrophysics Data System (ADS)

The properties of carbon nanotube (CNT)-polymer nanocomposites are far below than those calculated, mainly due to poor dispersion or interface quality. This is particularly difficult for single walled carbon nanotubes (SWNTs) as they tend to form bundles or ropes that are difficult to exfoliate. Supercritical fluid (SCF) assisted processing is one of the methods that can be used to exfoliate/disperse CNTs along with modifiying the interface of the CNTs. Molecular dynamics simulations were performed to understand how the surface modifiers behave near SWNT surface with and without the presence of SCF molecules. It is also important to understand the diffusivity of SCF molecules between SWNT bundles and the effect of surface modifiers on diffusion. Octane and n-perflourooctane molecules were used as surface modifiers with varying tethering density and carbon dioxide (CO2) was chosen as the SCF. Results showed that the system with highest number of n-perfluorooctanes presented the highest degree of success in separating the SWNTs in the presence of CO2.

Baysal, Nihat; Unsal, Banu; Ozisik, Rahmi

2006-03-01

471

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

This report describes research conducted between April 1, 2004 and June 30, 2004 on the preparation and use of dry regenerable sorbents for removal of carbon dioxide from flue gas. Support materials and supported sorbents were prepared by spray drying. Sorbents consisting of 20 to 50% sodium carbonate on a ceramic support were prepared by spray drying in batches of approximately 300 grams. The supported sorbents exhibited greater carbon dioxide capture rates than unsupported calcined sodium bicarbonate in laboratory tests. Preliminary process design and cost estimation for a retrofit application suggested that costs of a dry regenerable sodium carbonate-based process could be lower than those of a monoethanolamine absorption system. In both cases, the greatest part of the process costs come from power plant output reductions due to parasitic consumption of steam for recovery of carbon dioxide from the capture medium.

David A. Green; Brian S. Turk; Jeffrey W. Portzer; Raghubir P. Gupta; William J. McMichael; Thomas Nelson

2004-07-01

472

Effects of large-scale Amazon forest degradation on climate and air quality through fluxes of carbon dioxide, water, energy, mineral dust and isoprene.  

PubMed

Loss of large areas of Amazonian forest, through either direct human impact or climate change, could exert a number of influences on the regional and global climates. In the Met Office Hadley Centre coupled climate-carbon cycle model, a severe drying of this region initiates forest loss that exerts a number of feedbacks on global and regional climates, which magnify the drying and the forest degradation. This paper provides an overview of the multiple feedback process in the Hadley Centre model and discusses the implications of the results for the case of direct human-induced deforestation. It also examines additional potential effects of forest loss through changes in the emissions of mineral dust and biogenic volatile organic compounds. The implications of ecosystem-climate feedbacks for climate change mitigation and adaptation policies are also discussed. PMID:18267906

Betts, Richard; Sanderson, Michael; Woodward, Stepha