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1

Carbon Dioxide Laser Guidelines  

PubMed Central

The carbon dioxide (CO2) laser is a versatile tool that has applications in ablative lasing and caters to the needs of routine dermatological practice as well as the aesthetic, cosmetic and rejuvenation segments. This article details the basics of the laser physics as applicable to the CO2 laser and offers guidelines for use in many of the above indications. PMID:20808594

Krupa Shankar, DS; Chakravarthi, M; Shilpakar, Rachana

2009-01-01

2

Pulsed-discharge carbon dioxide lasers  

NASA Technical Reports Server (NTRS)

The purpose is to attempt a general introduction to pulsed carbon dioxide lasers of the kind used or proposed for laser radar applications. Laser physics is an excellent example of a cross-disciplinary topic, and the molecular spectroscopy, energy transfer, and plasma kinetics of the devices are explored. The concept of stimulated emission and population inversions is introduced, leading on to the molecular spectroscopy of the CO2 molecule. This is followed by a consideration of electron-impact pumping, and the pertinent energy transfer and relaxation processes which go on. Since the devices are plasma pumped, it is necessary to introduce a complex subject, but this is restricted to appropriate physics of glow discharges. Examples of representative devices are shown. The implications of the foregoing to plasma chemistry and gas life are discussed.

Willetts, David V.

1990-01-01

3

New Trends In Carbon Dioxide Laser Microsurgery  

NASA Astrophysics Data System (ADS)

The carbon dioxide laser has been used for cutting and cauterizing tissue in a variety of surgical procedures by means of a dry-field air/tissue interface approach. Recently, a new wet-field CO2 laser technique has been developed and is being used successfully in humans to seal intraocular fibrovascular fronds and retinal tears at the time of vitrectomy, to close rubeotic vessels in the iris, and to excise fibrovascular fronds and epiretinal membranes in cases of severe diabetic retinopathy. Specialized wet-field CO2 photosurgical probes for use in gynecologic microsurgery have been developed and are being studied experimentally. Other potential applications include otolaryngologic micro-surgery, neurosurgery, and gastrointestinal and urologic wet-field surgery.

Smith, M. R.; Miller, James B.

1981-05-01

4

Zenker's Diverticulum: Carbon Dioxide Laser Endoscopic Surgery  

PubMed Central

Nowadays endoscopic diverticulotomy is the surgical approach of the first choice in treatment of Zenker's diverticulum. We report our experience with this procedure and try to sum up recent recommendations for management of surgery and postoperative care. Data of 34 patients with Zenker's diverticulum, treated by endoscopic carbon dioxide laser diverticulotomy at the Department of Otorhinolaryngology and Head and Neck Surgery, 1st Faculty of Medicine, Charles University, University Hospital Motol, Prague, Czech Republic, were prospectively stored and followed in relatively short period from May 2009 to December 2013. The average length of diverticulum was 32?mm. The average duration of surgery was 32?min. The patients were fed via feeding tube for 6.1 days and antibiotics were administered for 7 days. Mean hospitalization time was 7.4 days. We observed one transient recurrent laryngeal nerve paralysis and no other serious complications. Recurrence rate was 3%. We recommend complete transection of the diverticular septum in one procedure, systemic antibiotic treatment and exclusion of transoral intake for minimally 5 days, and contrast oesophagogram before resumption of oral intake to exclude fistula. Open diverticulectomy should be reserved for cases with inadequate endoscopic exposure and for revision surgery for multiple recurrences from endoscopic diverticulotomies. PMID:24729975

Plzák, Jan; Zábrodský, Michal; Lukeš, Petr

2014-01-01

5

A high-pressure carbon dioxide gasdynamic laser  

NASA Technical Reports Server (NTRS)

A carbon dioxide gasdynamic laser was operated over a range of reservoir pressure and temperature, test-gas mixture, and nozzle geometry. A significant result is the dominant influence of nozzle geometry on laser power at high pressure. High reservoir pressure can be effectively utilized to increase laser power if nozzle geometry is chosen to efficiently freeze the test gas. Maximum power density increased from 3.3 W/cu cm of optical cavity volume for an inefficient nozzle to 83.4 W/cu cm at 115 atm for a more efficient nozzle. Variation in the composition of the test gas also caused large changes in laser power output. Most notable is the influence of the catalyst (helium or water vapor) that was used to depopulate the lower vibrational state of the carbon dioxide. Water caused an extreme deterioration of laser power at high pressure (100 atm), whereas, at low pressure the laser for the two catalysts approached similar values. It appears that at high pressure the depopulation of the upper laser level of the carbon dioxide by the water predominates over the lower state depopulation, thus destroying the inversion.

Kuehn, D. M.

1973-01-01

6

Carbon dioxide rapid superpulsed laser treatment of erythroplasia of Queyrat.  

PubMed

A single case of erythroplasia of Queyrat successfully treated by rapid superpulsed carbon dioxide laser emission is presented. The results of this single case and previous studies are compared with thos obtained by different modalities used in the past. PMID:6773202

Rosemberg, S K; Fuller, T A

1980-08-01

7

Treatment of chronic lip fissures with carbon dioxide laser  

Microsoft Academic Search

Resurfacing of cutaneous tissue with carbon dioxide laser increases the amount and quality of collagen and elastin subepithelially. We used this technique to ablate 12 chronic lip fissures in one woman and 10 men. Five patients’ fissures had persisted for durations ranging from several months to seven years; the other six had fissures that split between one and five times

James Combes; Timothy K. Mellor

2009-01-01

8

Carbon-dioxide laser treatment of eye lid lesions.  

PubMed

A commercially available carbon-dioxide laser has been used in the treatment of basal cell carcinoma, capillary haemangioma, papilloma and various other neoplastic lesions involving the lids and paraocular skin. Altogether 20 patients have been treated in the past two years. The results have been very encouraging. All lesions have healed without scarring, and to date there have been no recurrences. The advantage of CO2 laser irradiation is coagulation of blood and lymphatic channels in the treatment area, which prevents bleeding and limits dissemination of tumour cells. Also discussed is the mechanism of CO2 laser and the possibilities for the future. PMID:3922095

Chopdar, A

1985-01-01

9

Treatment of cutaneous leishmaniasis using a carbon dioxide laser.  

PubMed Central

Use of a carbon dioxide laser to vaporize the local lesions caused by cutaneous leishmaniasis is reported. A total of 108 patients have been treated in this way and followed up. The treatment reduces the management time of patients at least 1.5 times and is followed by satisfactory aesthetic outcomes. No recurrences have been observed among the 82 patients who have been followed up for 7 years. Images Fig. 1 Fig. 2 Fig. 3 PMID:1905204

Babajev, K. B.; Babajev, O. G.; Korepanov, V. I.

1991-01-01

10

Treatment of fibroelastolytic papulosis with fractionated carbon dioxide laser.  

PubMed

Fibroelastolytic papulosis (FEP) is an acquired elastic tissue disorder that presents as white-to-yellow papules and plaques usually occurring on the neck. Although the lesions are often asymptomatic, their appearance may be distressing to patients. FEP has been treated with topical tretinoin in one case report ( 1 ). Other reports have not mentioned treatment for this rare disorder ( 1-6 ). We present a case of FEP successfully treated with a fractionated carbon dioxide (CO2) laser. PMID:25415242

Chong, Summer P; Woodley, David T; Kim, Gene H; Shim, Elisabeth K

2014-12-01

11

Carbon dioxide laser treatment of erythroplasia of Queyrat.  

PubMed

We present a case of erythroplasia of Queyrat in a 77-year-old man involving the distal two-thirds of the penis. There was no urethral or periurethral involvement. Due to the location of the lesion, its recognition as carcinoma in situ, and the technical difficulty of cold-steel excision in this area, we used the carbon dioxide (CO2) laser to selectively destroy the tumor. In this case the laser provided controllable tissue destruction, ease of surgery, and excellent cosmesis. PMID:2501369

Greenbaum, S S; Glogau, R; Stegman, S J; Tromovitch, T A

1989-07-01

12

Measurement of Carbon Dioxide Column via Space Borne Laser Absorption  

NASA Technical Reports Server (NTRS)

In order to better understand the budget of carbon dioxide in the Earth's atmosphere it is necessary to develop a global high precision understanding of the carbon dioxide column. In order to uncover the 'missing sink that is responsible for the large discrepancies in the budget as we presently understand it calculation has indicated that measurement accuracy on the order of 1 ppm is necessary. Because typical column average CO2 has now reached 380 ppm this represents a precision on the order of .25% for these column measurements. No species has ever been measured from space at such a precision. In recognition of the importance of understanding the CO2 budget in order to evaluate its impact on global warming the National Research Council in its decadal survey report to NASA recommended planning for a laser based total CO2 mapping mission in the near future. The extreme measurement accuracy requirements on this mission places very strong requirements on the laser system used for the measurement. This work presents an analysis of the characteristics necessary in a laser system used to make this measurement. Consideration is given to the temperature dependence, pressure broadening, and pressure shift of the CO2 lines themselves and how these impact the laser system characteristics Several systems for meeting these requirements that are under investigation at various institutions in the US as well as Europe will be discussed.

Heaps, WIlliam S.

2007-01-01

13

Carbon dioxide laser treatment of external genital lesions.  

PubMed

Our entire clinical experience with the use of carbon dioxide (CO2) laser in the treatment of 67 patients with diverse external genital lesions is presented. Successful eradication was accomplished in 61 patients with wide distribution of condylomatous lesions, with 88 per cent responding to a single laser treatment. Excellent cosmetic results, as well as complete disappearance of balanitis xerotica obliterans and erythroplasia of Queyrat, were observed in 5 additional patients. Laser therapy, although not an established treatment option, appears to be a safe alternative and should be considered in those patients with recurrent genital condylomata, balanitis xerotica obliterans, as well as erythroplasia of Queyrat, not responding to well-known treatment modalities. PMID:3925610

Rosemberg, S K

1985-06-01

14

Type III female genital mutilation: Clinical implications and treatment by carbon dioxide laser surgery  

Microsoft Academic Search

Objective: The purpose of this study was to examine clinical implications of type III female genital mutilation and to evaluate the use of carbon dioxide laser surgery to restore vulvar opening and to treat associated epithelial inclusion cysts. Study design: Twenty-five infibulated patients underwent carbon dioxide laser treatment. Seven of the women (28%) were pregnant, between 10 and 37 weeks

Carlo Penna; M. Grazia Fallani; Massimiliano Fambrini; Elisa Zipoli; Mauro Marchionni

2002-01-01

15

Development of Laser-Induced Capillary Wave Method for Viscosity Measurement Using Pulsed Carbon Dioxide Laser  

Microsoft Academic Search

A new experimental apparatus, based on the laser-induced capillary wave method involving the use of a pulsed carbon dioxide laser (wavelength 10.6 µm, pulse width 50 ns, power 65 mJ) as a heating source has been developed. Since the present technique is applicable to a wide range of viscosity, this method is applicable to the process in which the viscosity drastically changes within

T. Oba; Y. Kido; Y. Nagasaka

2004-01-01

16

Clinical study on 71 anorectal cases treated by carbon dioxide laser  

NASA Astrophysics Data System (ADS)

This paper describes the effective result of carbon dioxide laser on type I and II internal hemorrhoids, mixed hemorrhoids, anal fissure or fistula, etc. At present, simple hemorrhoidectomy is less acceptable to patients for its excessive bleeding and severe pain during and after the operation. Therefore, the results of 71 anorectal cases of hemorrhoidectomy using carbon dioxide laser have been observed in our hospital. The rates of effective treatment and cure were 100% and 94.3%, respectively.

Li, Gui-hua

1993-03-01

17

LASCAT - DESIGN OF CATALYTIC MONOLITHS FOR CLOSED-CYCLE CARBON DIOXIDE LASERS  

NASA Technical Reports Server (NTRS)

Pulsed carbon dioxide lasers are useful in many areas, including aeronautics, space research, and weather monitoring. Most applications require a closed-cycle carbon dioxide laser, which is more portable and self-sustaining than an open-cycle system. Without a fresh carbon dioxide supply and provisions for byproduct disposal, the closed-cycle laser must recycle the carbon monoxide and oxygen gas produced by the lasing of carbon dioxide. The recombination of the carbon monoxide and oxygen gas byproducts to form a constant supply of carbon dioxide requires an active catalyst, which must be carefully designed to optimize laser performance in accordance with design requirements specific to the laser's application. LASCAT (Design of Catalytic Monoliths for Closed-Cycle Carbon Dioxide Lasers) aids in the design of the monolith catalyst by simulating the results of design decisions on the performance of the laser. In portable laser systems, considerations of size, weight, and cost are critical. LASCAT provides the opportunity for the designer to explore trade-offs between the catalyst activity, catalyst dimensions, monolith dimensions, pressure drop (a result of gas flow through the monolith), Oxygen gas conversion, and other variables. The program uses a flexible, simplified model of the monolith catalyst designed to determine the bulk-avarage gas temperature, composition, and pressure along its length. The user specifies values for the several parameters which define the catalyst's operating conditions, including monolith dimensions, gas inlet properties, thermal operation properties, and catalyst properties. LASCAT provides results which indicate whether the experimental design meets user-defined constraints such as limits on conversion rate, maximum gas temperature, and monolith weight. LASCAT is written in FORTRAN 77 and is designed for use with any text or character-based terminal or computer display. The program requires roughly 40 KB memory. LASCAT was developed in 1989. LASCAT is restricted for use by United States citizens only.

Guinn, K.

1994-01-01

18

Carbon dioxide (CO2) laser treatment of cutaneous papillomas in a common snapping turtle, Chelydra serpentina.  

PubMed

Carbon dioxide (CO2) laser was used to treat multiple cutaneous papillomas on an adult female common snapping turtle, Chelydra serpentina serpentina. A combination of excisional and ablative techniques provided excellent intraoperative visibility and postoperative results due to the laser's unique ability to incise and vaporize soft tissue. PMID:18634218

Raiti, Paul

2008-06-01

19

Histology of port-wine stain treated with carbon dioxide laser. A preliminary report.  

PubMed

The port-wine stain (PWS) has always been a difficult lesion to treat cosmetically. Laser surgery has proved to be a beneficial mode of therapy. Histology after argon laser surgery in successfully treated lesions is remarkable for blood vessels relatively free of erythrocytes. Our preliminary histologic findings in lesions successfully treated with carbon dioxide (CO2) laser surgery revealed similar results, although the mechanisms may be different. PMID:6429214

Buecker, J W; Ratz, J L; Richfield, D F

1984-06-01

20

Wound healing in porcine skin following low-output carbon dioxide laser irradiation of the incision  

SciTech Connect

Wound healing of scalpel incisions to the depth of adipose tissue closed with conventional methods was compared with closure by low-output carbon dioxide laser irradiation. In 3 Pitman-Moore minipigs wound healing was evaluated at intervals from 1 to 90 days by the following methods: clinical variables of wound healing; formation of the basement membrane components bullous pemphigoid antigen, laminin, and fibronectin; and histological evaluation of the regeneration of the epidermis, neovascularization, and elastin and collagen formation. There was no significant difference in healing between wounds closed by the various conventional methods and by the low-output carbon dioxide laser.

Robinson, J.K.; Garden, J.M.; Taute, P.M.; Leibovich, S.J.; Lautenschlager, E.P.; Hartz, R.S.

1987-06-01

21

Treatment of hidradenitis suppurativa with carbon dioxide laser excision and second-intention healing  

Microsoft Academic Search

Background: Hidradenitis suppurativa is a disabling disease. Although medical management can at times control the disease, the treatment of choice is surgical excision. Surgical defects have been managed by second-intention healing, simple surgical closure, or complex surgical repairs.Objective: Our purpose was to determine the benefit of carbon dioxide laser excision with healing by second intention to treat lesions of hidradenitis

Eric M Finley; John Louis Ratz

1996-01-01

22

Quantum cascade laser based spectrometer for in situ stable carbon dioxide isotope measurements  

Microsoft Academic Search

Simultaneous concentration measurements of the three main stable carbon dioxide isotopologues (16O12C16O, 16O13C16O and 18O12C16O) in ambient air are demonstrated. The instrument employs a quasi-room temperature, pulsed quantum cascade laser emitting at 4.3?m. Both the laser and the IR detector are thermoelectrically cooled, which greatly facilitates cryogenic-free, continuous operation. The Allan plot of the time series of the retrieved spectroscopic

B. Tuzson; M. J. Zeeman; M. S. Zahniser; L. Emmenegger

2008-01-01

23

Discovery of natural gain amplification in the 10-micrometer carbon dioxide laser bands on Mars - A natural laser  

NASA Technical Reports Server (NTRS)

Fully resolved intensity profiles of various lines in the carbon dioxide band at 10.4 micrometers have been measured on Mars with an infrared heterodyne spectrometer. Analysis of the line shapes shows that the Mars atmosphere exhibits positive gain in these lines. The detection of natural optical gain amplification enables identification of these lines as a definite natural laser.

Mumma, M. J.; Buhl, D.; Chin, G.; Deming, D.; Espenak, F.; Kostiuk, T.; Zipoy, D.

1981-01-01

24

Benign lesions of the nose, oral cavity, and oropharynx in children: excision by carbon dioxide laser.  

PubMed

The carbon dioxide laser was used to treat a group of pediatric patients with benign lesions of the upper aerodigestive tract exclusive of the larynx. Prior to development of the CO2 laser, excision of these lesions by conventional means often resulted in incomplete removal, significant bleeding, and postoperative edema resulting in airway obstruction. The CO2 laser, with its unique properties of precise excision, hemostatic effect, and minimal postoperative edema, has become the instrument of choice in the removal of these lesions. PMID:3931530

Crockett, D M; Healy, G B; McGill, T J; Friedman, E M

1985-01-01

25

Treatment of Ankyloglossia with Carbon Dioxide (CO2) Laser in a Pediatric Patient  

PubMed Central

Introduction: Laser surgery as an alternative for conventional surgical procedure has gained special attention. Using Carbon Dioxide (CO2) laser has some benefits like less post-operative pain, swelling and infection, decrease in risk of metastasis and edema, and less bleeding providing dry sites for surgery. Case Report: A 12 years old boy with lingual frenum with indication for excision was referred to the laser department of Tehran University of medical sciences dental school.CO2 laser was used with 10600 nm wavelength, 1.5 W output power, 100 Hz frequency and 400 ?sec pulse duration in non-contact mode. Results: The result of using CO2 laser was dry and bloodless field during operation, no post operative swelling, no pain or discomfort, with normal healing process. Conclusion: We suggest and stimulate the use of CO2 laser for soft tissue surgery because of elimination of suture, convenient coagulation, time saving, patients’ comfort and easy manipulation.

Chiniforush, Nasim; Ghadimi, Sara; Yarahmadi, Nazli; Kamali, Abbas

2013-01-01

26

Design of catalytic monoliths for closed-cycle carbon dioxide lasers  

NASA Technical Reports Server (NTRS)

A computer program was written that allows the design of catalytic monoliths for closed-cycle carbon dioxide lasers. Using design parameters obtained from workers at NASA Langley Research Center and from the literature, several specific monoliths were designed and the results were communicated to the research group working on this project at Langley. Two oral presentations were made at NASA-sponsored workshops - at Langley in January 1988 and in Gainesville, Florida in May 1988.

Herz, Richard K.

1988-01-01

27

JPL Carbon Dioxide Laser Absorption Spectrometer Data Processing Results for the 2010 Flight Campaign  

NASA Technical Reports Server (NTRS)

As a precursor to and validation of the core technology necessary for NASA's Active Sensing of CO2 Emissions over Nights, Days,and Seasons (ASCENDS) mission, we flew JPL's Carbon Dioxide Laser Absorption Spectrometer (CO2LAS) in a campaign of five flights onboard NASA's DC-8 Airborne Laboratory in July 2010. This is the latest in a series of annual flight campaigns that began in 2006, and our first on the DC-8 aircraft.

Jacob, Joseph C.; Spiers, Gary D.; Menzie, Robert T.; Christensen, Lance E.

2011-01-01

28

[Study of remote sensing the flux of carbon dioxide gas with tunable diode laser absorption spectroscopy].  

PubMed

Tunable diode laser absorption spectroscopy (TDLAS) technique is a new method to detect trace gas qualitatively or quantificationally based on the scan characteristic of the diode laser to obtain the absorption spectra in the characteristic absorption region. TDLAS is a highly sensitive, highly selective and fast time response trace gas detection technique. In the present paper, a DFB laser at room temperature was used as the light source, wavelength modulation method was employed, and the second harmonic signal of one absorption line near 1.578 microm of carbon dioxide molecule was measured. A system was built for online monitoring of carbon dioxide concentration within the optical path of more than 700 meters at different heights. Combined with Alonzo Mourning-Obukhov length and characteristic velocity detected by large aperture scintillometer, the flux of carbon dioxide gas calculated by the experiential formula is within -60-60 mg x m(-2) x s(-1). The comparison of the datea detected by TDLAS system and the eddy covariance showed that the change of the data detected by TDLAS had a similar trend to that detected by the eddy covariance, and the best results can be produced by this method, breaking through the phenomenon of only providing the flux of trace gases near the ground at present, and making the measurement of trace gas fluxes within a large area possible. PMID:21595244

Song, Xue-mei; Liu, Jian-guo; Zhang, Yu-jun; Lu, Yi-huai; Zeng, Zong-yong; He, Ying; Cui, Yi-ben; Tian, Yong-zhi; Tian, Lin

2011-03-01

29

Selective Removal of Dental Composite using a Rapidly Scanned Carbon Dioxide Laser.  

PubMed

Dental restorative materials are color matched to the tooth and are difficult to remove by mechanical means without excessive removal or damage to peripheral enamel and dentin. Lasers are ideally suited for selective ablation to minimize healthy tissue loss when replacing existing restorations, sealants or removing composite adhesives such as residual composite left after debonding orthodontic brackets. In this study a carbon dioxide laser operating at high laser pulse repetition rates integrated with a galvanometer based scanner was used to selectively remove composite from tooth surfaces. A diode array spectrometer was used to measure the plume emission after each laser pulse and determine if the ablated material was tooth mineral or composite. The composite was placed on tooth buccal and occlusal surfaces and the carbon dioxide laser was scanned across the surface to selectively remove the composite without excessive damage to the underlying sound enamel. The residual composite and the damage to the underlying enamel was evaluated using optical microscopy. The laser was able to rapidly remove the composites rapidly from both surfaces with minimal damage to the underlying sound enamel. PMID:21927546

Chan, Kenneth H; Fried, Daniel

2011-01-01

30

Selective removal of dental composite using a rapidly scanned carbon dioxide laser  

NASA Astrophysics Data System (ADS)

Dental restorative materials are color matched to the tooth and are difficult to remove by mechanical means without excessive removal or damage to peripheral enamel and dentin. Lasers are ideally suited for selective ablation to minimize healthy tissue loss when replacing existing restorations, sealants or removing composite adhesives such as residual composite left after debonding orthodontic brackets. In this study a carbon dioxide laser operating at high laser pulse repetition rates integrated with a galvanometer based scanner was used to selectively remove composite from tooth surfaces. A diode array spectrometer was used to measure the plume emission after each laser pulse and determine if the ablated material was tooth mineral or composite. The composite was placed on tooth buccal and occlusal surfaces and the carbon dioxide laser was scanned across the surface to selectively remove the composite without excessive damage to the underlying sound enamel. The residual composite and the damage to the underlying enamel was evaluated using optical microscopy. The laser was able to rapidly remove the composites rapidly from both surfaces with minimal damage to the underlying sound enamel.

Chan, Kenneth H.; Fried, Daniel

2011-03-01

31

Carbon dioxide laser in ophthalmic plastic and orbital surgery.  

PubMed

The CO2 laser cuts tissue by flash boiling extracellular or intracellular water molecules in contact with the beam. This vaporization sterilizes the tissue and seals capillaries. The CO2 laser seems most useful in ophthalmology to vaporize lymphangiomas and capillary hemangiomas and to provide hemostasis in patients with bleeding disorders. The cutting beam of the CO2 laser can be attached to the operating microscope to facilitate surgery deep within the orbit. The effectiveness of the CO2 cutting action depends upon water content of the tissue rather than tissue color as with argon and krypton lasers. Skin incisions show less scarring when made with conventional scalpel, but more precise surface cutting lasers may allow more precise microsurgical excision of eyelid tumors than can now be accomplished with a scalpel. PMID:4069558

Wesley, R E; Bond, J B

1985-10-01

32

Folded Rf-Excited Carbon Dioxide Waveguide Lasers  

NASA Astrophysics Data System (ADS)

Available from UMI in association with The British Library. This thesis describes theoretical and experimental work on RF excited CO_2 waveguide lasers and amplifiers. The mode coupling losses at a bend in a folded waveguide have been evaluated as a function of the selectable parameters to determine the low-loss folding geometries. A direct comparison is made between three types of optical arrangement used for folding in a compact, sealed-off, Z-fold CO_2 waveguide laser excited by a transverse RF discharge. In particular, the measured laser output power as a function of discharge conditions and mirror alignment for plane and curved mirror, and partial waveguide folded resonators are compared. The Z-fold laser output power is predicted by incorporating the known and estimated laser parameters into a Rigrod-type analysis. A simultaneous solution of the Rigrod equations predicting the laser powers for different intra-cavity gain lengths is used with the experimental data to derive the discharge and resonator parameters. Experimental results are in good agreement with the theoretical predictions, and suggest that a ~1% power loss per fold has been achieved with partial waveguide folding. Also, the preliminary theoretical results of a multi-mode resonator model predicting the laser output power as a function of the angular mis-alignment of one of the Z-fold laser folding mirrors are in qualitative agreement with the experimental determinations. Experiments related to laser efficiency and frequency stability are discussed briefly. These include an investigation into an automatic impedance matching scheme for dynamic optimisation of the power transfer efficiency between RF generator and the laser head; the Opto-Hertzian effect (RF equivalent to the opto-Galvanic effect) for laser frequency stabilisation; a novel parallel-resonant distributed inductance excitation technique using a multi-start solenoid; and finally, identification of hooting laser resonator modes responsible for impeding heterodyne measurements when a clean RF spectrum is required. In addition, theoretical and experimental studies of laser amplification are presented. The suitability of folded waveguide and non-waveguide structures for power amplification or pre-amplification is assessed to determine their applicability to coherent LIDAR. Optical amplification of wideband transmitter and/or receiver signals is considered a favourable way of improving the discrimination of range and velocity determinations. Finally, as a result of this work, up to 53.4 Watts output power in a high quality fundamental Gaussian beam has been obtained from a compact, sealed-off, Z-fold CO_2 waveguide laser with a 115 cm discharge length, which implies a specific power performance of 0.46 W/cm. Efficiencies (laser output power/RF input power) of up to 9.2% have also been observed.

Jackson, Paul Edward

1988-12-01

33

The treatment of port wine stains with the carbon dioxide laser.  

PubMed

The carbon dioxide (CO2) laser was used to treat 51 patients with port wine stains (PWS). Twenty-nine patients were adults who had failed to respond to argon or continuous wave dye laser therapy and 22 patients were children with pink PWS. Follow-up assessment of 40 patients 12 months after treatment revealed an excellent or good result in 74% of adults and 53% of children. The results in adult 'therapeutic failures' was encouraging and CO2 laser therapy can be advised for this group. Two children had a poor result, one with a hypertrophic scar, and treatment in this age group with the CO2 laser should be considered with caution. PMID:2119215

Lanigan, S W; Cotterill, J A

1990-08-01

34

Laryngeal stenosis following carbon dioxide laser in subglottic hemangioma. Report of three cases.  

PubMed

Recent reports recommend carbon dioxide laser as the safest and the most effective treatment for subglottic hemangioma in infants. Though one report mentions the development of a small amount of subglottic scarring in an 8-month-old girl after resection of a subglottic hemangioma, there is insufficient emphasis in the literature with respect to stenosis as a complication of CO2 laser therapy. The authors present three cases of severe laryngotracheal stenosis developing in infants treated with the CO2 laser for subglottic hemangioma. The presentation of these three cases should be a warning to the otolaryngologist that the use of the CO2 laser is not without significant risk of scar tissue formation. PMID:3931531

Cotton, R T; Tewfik, T L

1985-01-01

35

Optically pumped carbon dioxide laser mixtures. [using solar radiation  

NASA Technical Reports Server (NTRS)

This work explores the concept of blackbody radiation pumping of CO2 gas as a step toward utilization of solar radiation as a pumping source for laser action. To demonstrate this concept, an experiment was performed in which laser gas mixtures were exposed to 1500 K thermal radiation for brief periods of time. A gain of 2.8 x 10 to the -3rd reciprocal centimeters has been measured at 10.6 microns in a CO2-He gas mixture of 1 Torr pressure. A simple analytical model is used to describe the rate of change of energy of the vibrational modes of CO2 and to predict the gain. Agreement between the prediction and experiment is good.

Yesil, O.; Christiansen, W. H.

1979-01-01

36

Selective Removal of Demineralization Using Near Infrared Cross Polarization Reflectance and a Carbon Dioxide Laser  

PubMed Central

Lasers can ablate/remove tissue in a non-contact mode of operation and a pulsed laser beam does not interfere with the ability to image the tooth surface, therefore lasers are ideally suited for integration with imaging devices for image-guided ablation. Laser energy can be rapidly and efficiently delivered to tooth surfaces using a digitally controlled laser beam scanning system for precise and selective laser ablation with minimal loss of healthy tissues. Under the appropriate irradiation conditions such laser energy can induce beneficial chemical and morphological changes in the walls of the drilled cavity that can increase resistance to further dental decay and produce surfaces with enhanced adhesive properties to restorative materials. Previous studies have shown that images acquired using near-IR transillumination, optical coherence tomography and fluorescence can be used to guide the laser for selective removal of demineralized enamel. Recent studies have shown that NIR reflectance measurements at 1470-nm can be used to obtain images of enamel demineralization with very high contrast. The purpose of this study was to demonstrate that image guided ablation of occlusal lesions can be successfully carried out using a NIR reflectance imaging system coupled with a carbon dioxide laser operating at 9.3-?m with high pulse repetition rates. PMID:24357906

Chan, Kenneth H.; Fried, Daniel

2012-01-01

37

Airborne Carbon Dioxide Laser Absorption Spectrometer for IPDA Measurements of Tropospheric CO2: Recent Results  

NASA Technical Reports Server (NTRS)

The National Research Council's decadal survey on Earth Science and Applications from Space[1] recommended the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission for launch in 2013-2016 as a logical follow-on to the Orbiting Carbon Observatory (OCO) which is scheduled for launch in late 2008 [2]. The use of a laser absorption measurement technique provides the required ability to make day and night measurements of CO2 over all latitudes and seasons. As a demonstrator for an approach to meeting the instrument needs for the ASCENDS mission we have developed the airborne Carbon Dioxide Laser Absorption Spectrometer (CO2LAS) which uses the Integrated Path Differential Absorption (IPDA) Spectrometer [3] technique operating in the 2 micron wavelength region.. During 2006 a short engineering checkout flight of the CO2LAS was conducted and the results presented previously [4]. Several short flight campaigns were conducted during 2007 and we report results from these campaigns.

Spiers, Gary D.; Menzies, Robert T.

2008-01-01

38

Enamel fusion using a carbon dioxide laser: A technique for sealing pits and fissures  

SciTech Connect

The well-established enhanced resistance of lased enamel to demineralization is the basis for clinical application of the carbon dioxide laser to caries prevention. This in vitro study examined the effect of focused infrared laser radiation on sound enamel and early pit and fissure caries. Low power levels (2-5 W) induced localized melting and resolidification of enamel with little surface destruction. For sound fissures, fusion of enamel from the lateral walls of the fissure eliminated the fissure space, providing a sealant effect; while in carious fissures, carious enamel was vaporized and adjacent sound enamel fused to partially eliminate the defect. The technique for enamel fusion using CO2 lasers has potential application for sealing pits and fissures and producing physicochemical alterations in enamel which may have preventive benefits.

Walsh, L.J.; Perham, S.J. (University of Queensland Dental School, Brisbane (England))

1991-05-01

39

Monolith catalysts for closed-cycle carbon dioxide lasers  

NASA Technical Reports Server (NTRS)

The objective was to explore ways of making a monolithic form of catalyst for CO2 lasers. The approach chosen was to pelletize the catalyst material, Au/MnO2 powder, and epoxy the pellets to stainless steel sheets as structural supports. The CO oxidation reaction over Au/MnO2 powder was found to be first overall, and the reaction rate constant at room temperature was 4.4 +/- 0.3 cc/(g x sec). The activation energy was 5.7 kcal/mol. The BET surface area of the pellets was found to vary from 125 to 140 sq m/g between different batches of catalyst. Pellets epoxied to stainless steel strips showed no sign of fracture or dusting when subjected to thermal tests. Pellets can be dropped onto hard surfaces with chipping of edges but no breakage of the pellets. Mechanical strength tests performed on the pellets showed that the crush strength is roughly one-fourth of the pelletizing force. The apparent activity and activation energy over the pellets were found to be less than over the powdered form of the catalyst. The lower apparent activity and activation energy of the pellets are due to the fact that the internal surface area of a pellet is not exposed to the reactant concentration present in the flowing gas as a result of intrapellet diffusion resistance. Effectiveness factors varied from 0.44, for pellets having thickness of 2 mm and attached with epoxy to a stainless steel strip. The epoxy and the stainless steel strip were found to simply block off one of the circular faces of the pellets. The epoxy did not penetrate the pellets and block the active sites. The values of the effective diffusivities were estimated to be between 2.3 x 10(exp -3) and 4.9 x 10(exp -3) sq cm/s. With measurements performed on one powder sample and one pellet configuration, reasonable accurate predictions can be made of conversions that would be obtained with other pellet thickness and configurations.

Herz, Richard K.; Badlani, Ajay

1991-01-01

40

Design of catalytic monoliths for closed-cycle carbon dioxide lasers  

NASA Technical Reports Server (NTRS)

Pulsed carbon dioxide (CO2) lasers have many applications in aeronautics, space research, weather monitoring and other areas. Full exploitation of the potential of these lasers in hampered by the dissociation of CO2 that occurs during laser operation. The development of closed-cycle CO2 lasers requires active CO-O2 recombination (CO oxidation) catalyst and design methods for implementation of catalysts in CO2 laser systems. A monolith catalyst section model and associated design computer program, LASCAT, are presented to assist in the design of a monolith catalyst section of a closed cycle CO2 laser system. Using LASCAT,the designer is able to specify a number of system parameters and determine the monolith section performance. Trade-offs between the catalyst activity, catalyst dimensions, monolith dimensions, pressure drop, O2 conversion, and other variables can be explored and adjusted to meet system design specifications. An introduction describes a typical closed-cycle CO2 system, and indicates some advantages of a closed cycle laser system over an open cycle system and some advantages of monolith support over other types of supports. The development and use of a monolith catalyst model is presented. The results of a design study and a discussion of general design rules are given.

Herz, R. K.; Guinn, K.; Goldblum, S.; Noskowski, E.

1989-01-01

41

CARBON DIOXIDE EMISSION REDUCTION  

E-print Network

CARBON DIOXIDE EMISSION REDUCTION TECHNOLOGIES AND MEASURES IN US INDUSTRIAL SECTOR FINAL REPORT TO KOREA ENVIRONMENT INSTITUTE FEBRUARY 2007 #12;B #12;C CARBON DIOXIDE EMISSION REDUCTION TECHNOLOGIES.5 Primary Energy Use and Carbon Dioxide Emissions for Selected US Chemical Subsectors in 1994

Delaware, University of

42

Treatment of nodular facial angiofibromas in tuberous sclerosis, using ultrapulse carbon dioxide laser.  

PubMed

Tuberous sclerosis (TS) is a genodermatosis characterized by facial angiofibromas (FAs). These tumours cause aesthetic disfigurement and obstruction of vision, and haemorrhage when traumatized, which can lead to emotional distress and relationship difficulties. We report the case of a 35-year-old patient with extensive TS-associated FAs that were treated with an ultrapulse carbon dioxide laser (UPCDL). UPCDL laser seems to be a easy, useful and convenient tool for the treatment of nodular FAs, which provides good aesthetic results, and a positive response from patients, who report high levels of satisfaction with the results. Minimal recurrence of the tumours occurred during long-term follow-up, and these were successfully treated with UPCDL. It is not yet possible to correct the genetic alterations underlying TS, but UPCDL treatment is a convenient tool to improve the facial appearance of patients with severe FAs. PMID:24890518

Biondo, G; Greco, S; Mavilia, L; Mercuri, S R

2014-08-01

43

Bone healing of the sheep tibia shaft after carbon dioxide laser osteotomy: histological results.  

PubMed

The aim of the study was to compare the histological results after complete osteotomies of the sheep tibia using either the prototype carbon dioxide (CO(2)) laser osteotome 'OsteoLAS' (n = 12) or an oscillating saw (n = 12). The laser parameters were as follows: wavelength 10.6 microm; energy of laser pulses 75-85 mJ; pulse duration 80 mus; pulse repetition rate 200 Hz; spot diameter 460 mum (1/e(2) level); radiant exposure 45-51 J/cm(2); peak irradiance 0.56-0.64 MW/cm(2). Both groups were divided into two subgroups (n = 6), and the animals were killed after 4 weeks or 12 weeks, respectively. Light and fluorescence microscopy with semiquantitative analysis and histomorphometry were performed to compare bone healing. Charring-free laser osteotomies were possible up to a depth of 20 mm with the short-pulsed CO(2) laser. The laser, however, required a significantly longer time to perform, and a wedge-shaped gap was present on the cis-cortex. After 4 weeks the osteotomy gaps were almost unchanged in both groups and filled with connective tissue. After 12 weeks the gaps were filled with newly formed bone in both groups. Primary gap healing was predominant in the laser group and longitudinal cortical remodelling in the control group. On a cellular level, no fundamental differences were observed for early and late stages of bone healing. Further research has to be focussed on improving the CO(2) laser ostetome in order to reduce the long duration of the laser osteotomy and the necessity of creating a wedge-shaped cut in thick bones. PMID:19680713

Kuttenberger, Johannes J; Waibel, Alessa; Stübinger, Stefan; Werner, Martin; Klasing, Manfred; Ivanenko, Mikhail; Hering, Peter; von Rechenberg, Brigitte; Sader, Robert; Zeilhofer, Hans-Florian

2010-03-01

44

Proximal gastric vagotomy with carbon dioxide laser: Experimental studies in animals  

SciTech Connect

Proximal gastric vagotomy has been widely used as a surgical treatment for peptic ulcer disease. However, it is technically complex and time-consuming. Moreover, it may cause circulatory problems in the gastric mucosa. We have reported a new method of blood flow-preserving vagotomy with a carbon dioxide laser (CO2 laser vagotomy) developed in our laboratory. To assess its efficacy, we used cysteamine-induced ulcer and measured gastric mucosal blood flow in rats. The incidence of cysteamine-induced ulcer formation was reduced significantly in the group that underwent CO{sub 2} laser vagotomy compared with a group treated with proximal gastric vagotomy. Gastric mucosal blood flow was significantly better in the CO{sub 2} laser vagotomy group. Long-term follow-up of acid reduction was evaluated in dogs by the pentagastrin-stimulation test. Acid reduction in dogs was satisfactory during the 12 months of this study. CO{sub 2} laser vagotomy is a new, easy, time-saving, and circulatory-preserving technique for peptic ulcer disease.

Kadota, T.; Mimura, K.; Kanabe, S.; Ohsaki, Y.; Tamakuma, S. (National Defense Medical College, Saitama (Japan))

1990-06-01

45

Use of the carbon dioxide laser in guided tissue regeneration wound healing in the beagle dog  

NASA Astrophysics Data System (ADS)

The concept of guided tissue regeneration (GTR) allowing cells from the periodontal ligament and alveolar bone to repopulate the treated root surface has shown the ability to obtain periodontal new attachment. Healing studies have also shown that conventional GTR therapy still does not exclude all the epithelium. This epithelial proliferation apically interferes with the establishment of the new connective tissue attachment to the root surface. The objective of this research study was to examine whether controlled de-epithelialization with the carbon dioxide laser during the healing phase after periodontal surgery, would retard the apical migration of the epithelium and thereby enhance the results obtained through guided tissue regeneration. Eight beagle dogs were used, the experimental side received de-epithelialization with the CO2 laser in conjunction with flap reflection and surgically created buccal osseous defects. Selected defects on each side were treated with ePTFE periodontal membranes. The laser de-epithelialization was repeated every 10 days until removal of the membranes. The control side received the same surgical treatment without laser application. This experimental design allowed histologic study of the new attachment obtained in defects treated with flap debridement with or without laser de-epithelialization and with or without ePTFE membranes. A statistical analysis was performed on the histometric data from 48 teeth in the 8 dogs after 4 months of healing. The results showed significant amounts of new attachment obtained from all four treatment modalities with no statistically significant differences for any one treatment. However, the trend towards enhanced regeneration with the combined treatment of laser and membrane vs. membrane alone or debridement alone was evident. The histologic analysis revealed a significant amount of newly formed `fat cementum' seen only on the laser treated teeth. This feature was the most remarkable finding of the study and warrants further research to understand the origin of this phenomenon.

Rossmann, Jeffrey A.; Parlar, Ates; Abdel-Ghaffar, Khaled A.; El-Khouli, Amr M.; Israel, Michael

1996-04-01

46

Scanner-assisted carbon dioxide laser surgery: A retrospective follow-up study of patients with hidradenitis suppurativa  

Microsoft Academic Search

Background: The chronic fistulating lesions of hidradenitis suppurativa spread by contiguous growth, and all affected tissue needs to be surgically removed. Objective: The aim of our study was to evaluate a surgical method for treatment of Hurley stage II hidradenitis suppurativa (HS), the carbon dioxide laser rapid-beam optomechanical scanner system in continuous mode. Methods: Thirty-four patients were evaluated after treatment;

Jan Lapins; Karin Sartorius; Lennart Emtestam

2002-01-01

47

Carbon Dioxide & Global Warming  

E-print Network

Carbon Dioxide & Global Warming University of MiaMi rosenstiel sChool of Marine anD atMospheriC s ­ it allows sunlight in, but gases in the atmosphere, especially carbon dioxide (CO2 ), allow less to breathe. Respi- ration by these organisms returns this carbon to the atmosphere as CO2 . Unfortunately

Miami, University of

48

The carbon dioxide cycle  

USGS Publications Warehouse

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

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

2005-01-01

49

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.

50

Feasibility and clinical outcomes of transoral robotic surgery and transoral robot-assisted carbon dioxide laser for hypopharyngeal carcinoma.  

PubMed

Transoral robotic surgery (TORS) has been used as a novel procedure for squamous cell carcinoma of the laryngopharyngeal cancers with encouraging outcomes. The safety, feasibility, and efficacy regarding this approach have previously been demonstrated. There are several studies proposing the benefit of combining TORS with carbon dioxide (CO2) laser in resecting upper aerodigestive tract tumors. We report a series of patients with hypopharyngeal carcinoma treated with primary TORS with or without the flexible carbon dioxide (CO2) laser. All TORS resections were completed without any intraoperative complication. None required conversion to an open procedure. Clinical outcomes in this preliminary analysis indicate that magnified view, 3D visualization with the wristed instruments and tremor reduction technology of robotic experience, allow en bloc resection of early stage hypopharyngeal cancers. TORS with CO2 laser is a promising, minimally invasive surgical alternative for the treatment of hypopharyngeal tumors with comparable oncologic outcomes. PMID:25478973

Durmus, Kasim; Kucur, Cuneyt; Uysal, Ismail O; Dziegielewski, Peter T; Ozer, Enver

2015-01-01

51

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.

2014-01-28

52

Carbon Dioxide Emission Estimates  

NSDL National Science Digital Library

The Carbon Dioxide Information Analysis Center of the Oak Ridge National Laboratory provides this new data on carbon dioxide emissions from fossil fuel burning, hydraulic cement production, and gas flaring in 1995. Data for one degree grid cells can be downloaded from the site in addition to code for analysis of the data.

53

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

54

Microscopic and ultrastructural modifications of postmenopausal atrophic vaginal mucosa after fractional carbon dioxide laser treatment.  

PubMed

Vaginal atrophy occurring during menopause is closely related to the dramatic decrease in ovarian estrogens due to the loss of follicular activity. Particularly, significant changes occur in the structure of the vaginal mucosa, with consequent impairment of many physiological functions. In this study, carried out on bioptic vaginal mucosa samples from postmenopausal, nonestrogenized women, we present microscopic and ultrastructural modifications of vaginal mucosa following fractional carbon dioxide (CO2) laser treatment. We observed the restoration of the vaginal thick squamous stratified epithelium with a significant storage of glycogen in the epithelial cells and a high degree of glycogen-rich shedding cells at the epithelial surface. Moreover, in the connective tissue constituting the lamina propria, active fibroblasts synthesized new components of the extracellular matrix including collagen and ground substance (extrafibrillar matrix) molecules. Differently from atrophic mucosa, newly-formed papillae of connective tissue indented in the epithelium and typical blood capillaries penetrating inside the papillae, were also observed. Our morphological findings support the effectiveness of fractional CO2 laser application for the restoration of vaginal mucosa structure and related physiological trophism. These findings clearly coupled with striking clinical relief from symptoms suffered by the patients before treatment. PMID:25410301

Zerbinati, Nicola; Serati, Maurizio; Origoni, Massimo; Candiani, Massimo; Iannitti, Tommaso; Salvatore, Stefano; Marotta, Francesco; Calligaro, Alberto

2015-01-01

55

Hypertrophic Scarring of the Neck Following Ablative Fractional Carbon Dioxide Laser Resurfacing  

PubMed Central

Background Ablative fractional carbon dioxide (CO2) laser treatments have gained popularity due to their efficacy, shortened downtime, and decreased potential for scarring in comparison to traditional ablative CO2 resurfacing. To date, scarring with fractional CO2 lasers has not been reported. Objective Five patients treated with the same fractional CO2 laser technology for photodamage of the neck were referred to our practices 1–3 months after treatment. Each patient developed scarring. Of the five cases, two are discussed in detail. The first was treated under general anesthesia on the face and anterior neck at a pulse energy of 30 mJ (859 ?m depth) with 25% coverage. Eleven days after treatment, three non-healing areas along the horizontal skin folds of the anterior neck were noted. At 2 weeks after CO2 ablative fractional resurfacing, these areas had become thickened. These raised areas were treated with a non-ablative fractionated 1,550 nm laser to modify the wound healing milieu. One week later, distinct firm pale papules in linear arrays with mild hypopigmentation had developed along involved neck skin folds. Skin biopsy was performed. For the second patient, the neck was treated at a pulse energy of 20 mJ (630 ?m depth) with 30% coverage of the exposed skin, with a total treatment energy of 5.0 kJ. Minimal crusting was noted on the neck throughout the initial healing phase of 2 weeks. She then experienced tightness on her neck. Approximately 3 weeks after treatment, she developed multiple vertical and horizontal hypertrophic scars (HS). Results Histopathology for the first case confirmed the presence of a hypertrophic scar. The papules in this case completely resolved with mild residual hypopigmentation after treatment with topical corticosteroids. HS failed to resolve in the second case to date after 1 month. Conclusion As with traditional ablative CO2 laser resurfacing, HS is a potential complication of ablative fractional CO2 laser resurfacing, particularly on the neck. With early diagnosis and appropriate treatment HS of neck skin may be reversible. We urge caution when treating the neck with this device and close attention to wound care in the post-operative period. PMID:19291746

Avram, Mathew M.; Tope, Whitney D.; Yu, Thomas; Szachowicz, Edward; Nelson, J. Stuart

2009-01-01

56

Progress on High-Energy 2-micron Solid State Laser for NASA Space-Based Wind and Carbon Dioxide Measurements  

NASA Technical Reports Server (NTRS)

Sustained research efforts at NASA Langley Research Center during last fifteen years have resulted in significant advancement of a 2-micron diode-pumped, solid-state laser transmitter for wind and carbon dioxide measurements from ground, air and space-borne platforms. Solid-state 2-micron laser is a key subsystem for a coherent Doppler lidar that measures the horizontal and vertical wind velocities with high precision and resolution. The same laser, after a few modifications, can also be used in a Differential Absorption Lidar system for measuring atmospheric CO2 concentration profiles. Researchers at NASA Langley Research Center have developed a compact, flight capable, high energy, injection seeded, 2-micron laser transmitter for ground and airborne wind and carbon dioxide measurements. It is capable of producing 250 mJ at 10 Hz by an oscillator and one amplifier. This compact laser transmitter was integrated into a mobile trailer based coherent Doppler wind and CO2 DIAL system and was deployed during field measurement campaigns. This paper will give an overview of 2-micron solid-state laser technology development and discuss results from recent ground-based field measurements.

Singh, Upendra N.

2011-01-01

57

Recent measurement results from the Carbon Dioxide Laser Absorption Spectrometer for the ASCENDS Mission  

NASA Astrophysics Data System (ADS)

The JPL developed Carbon Dioxide Laser Absorption Spectrometer, CO2LAS flew on the NASA DC-8 aircraft during the February-March 2013 ASCENDS flight campaign. The instrument measures the column averaged CO2 between the aircraft and the ground. Nine flights were conducted over a variety of surface cover types through out the Western United States. In-situ measurements of CO2 were made using both a commercial PICARRO sensor and the NASA LaRC developed Atmospheric Vertical Observations of CO2 in the Earth's Troposphere, AVOCET instrument onboard the aircraft. Auxiliary measurements of atmospheric pressure, temperature and water vapor profiles were collected via balloon sondes launched from the ground during flights over California and Nevada. The purpose of this series of flights was to demonstrate the ability to make column CO2 measurements over a variety of surface types including snow. We will present results from these most recent flights together with refined results from the prior 2011 campaign. We will discuss algorithm changes and improvements that lead to a more automated processing regime and will conclude with plans for instrument improvements for the next series of flights that are tentatively planned for summer 2014.

Spiers, G. D.; Menzies, R. T.; Jacob, J.; Abshire, J. B.; Riris, H.; Yang, M. M.; Choi, Y.; Meadows, B. L.

2013-12-01

58

Carbon dioxide sensor  

DOEpatents

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

Dutta, Prabir K. (Worthington, OH); Lee, Inhee (Columbus, OH); Akbar, Sheikh A. (Hilliard, OH)

2011-11-15

59

Clinical effects of betamethasone and hyaluronan, and of defocalized carbon dioxide laser treatment on traumatic arthritis in the fetlock joints of horses.  

PubMed

The clinical effects of intra-articular betamethasone together with hyaluronan (betaM/HA) and treatment with a defocalized carbon dioxide laser on acute traumatic arthritis of the fetlock joint were assessed. The horses in these studies were selected using a thorough lameness examination, including intra-articular anaesthesia abolishing the lameness. This investigation comprised an observer-blind study, including 10 sport horses (10 joints), and a prospective study, including 180 sport horses (333 joints). In both studies, the material was divided into two groups treated with either betaM/HA or a carbon dioxide laser. The treatment doses were 12 mg of betaM, 20 mg of HA or 60 J/cm2 of treated area. Convalescence before training was 21 days for both groups in the observer-blind study. In the prospective study, convalescence in the betaM/HA group was 21 days but was only 7 days for the laser-treated group. In the observer-blind study, three of five treated joints recovered in both cohorts. In the prospective study, the groups had significantly different recovery rates--68% of the betaM/HA-treated joints and 80% of the carbon dioxide laser-treated joints. These results indicate that the defocalized carbon dioxide laser should be an applicable mode of treatment of acute traumatic synovitis in horses. However, the biochemical functions related to carbon dioxide laser treatment require further elucidation. PMID:12069260

Lindholm, A C; Swensson, U; de Mitri, N; Collinder, E

2002-05-01

60

Comparison of the effect of the carbon dioxide laser and the bipolar coagulator on the cat brain  

SciTech Connect

The carbon dioxide laser has recently received clinical acceptance in neurosurgical practice. There are, however, few studies reported in the neurosurgical literature, either clinical or experimental, concerning its safety or efficacy on a physiological level by comparison to a more conventional tool. This study is not a description of a surgical technique, but is rather a basic physiological comparison of two surgical instruments. In this study, 11 cats were pretreated with the protein-bound dye, Evans blue. A corticotomy was performed in one hemisphere with the carbon dioxide laser and in the other with a microbipolar coagulator and a sharp blade. The subsequent extravasation of dye was presumed to be proportional to the amount of blood-brain barrier disruption associated with each lesion. When effective power settings for the two devices were compared, the laser lesions had significantly less extravasation of blue dye. This indicated that there was less damage to the blood-brain barrier surrounding laser corticotomy than surrounding conventional bipolar coagulation and sharp dissection at comparable power settings for each modality.

Cozzens, J.W.; Cerullo, L.J.

1985-04-01

61

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.

2012-12-26

62

Carbon Dioxide Exercise  

NSDL National Science Digital Library

In this activity, students work in groups, plotting carbon dioxide concentrations over time on overheads and estimating the rate of change over five years. Stacked together, the overheads for the whole class show an increase on carbon dioxide over five years and annual variation driven by photosynthesis. This exercise enables students to practice basic quantitative skills and understand how important sampling intervals can be when studying changes over time. A goal is to see how small sample size may give incomplete picture of data.

Richardson, Randy; Collection, Serc -.

63

Carbon dioxide laser as a surgical instrument for sarcoid therapy--a retrospective study on 60 cases.  

PubMed Central

The objective of this retrospective clinical study was to evaluate the carbon dioxide laser in the treatment of single and multiple sarcoids in 60 animals (44 horses, 13 donkeys, 2 mules, and 1 pony). Only animals that had been operated on 6 mo or more ago were included. Recurrence, new manifestation rate, and cosmetic outcome were determined. Recurrence was observed in 23 (38%) individuals. Animals with new sarcoid manifestation with or without recurrence of a sarcoid were observed in 35 cases (58%). Cases of scar tissue formation and, rarely, leukotrichia were observed. Animals presented with multiple sarcoids were more predisposed to recurrence. Donkeys showed a significantly lower recurrence rate than horses. PMID:9426943

Carstanjen, B; Jordan, P; Lepage, O M

1997-01-01

64

Histologic responses of port-wine stains treated by argon, carbon dioxide, and tunable dye lasers. A preliminary report.  

PubMed

Although the blue-green argon laser light has been used successfully to treat port-wine stains (PWSs) for many years, it produces substantial epidermal damage. We have previously shown in normal human skin that pulsed yellow tunable dye lasers (577-nm wavelength) can cause highly selective damage to cutaneous microvessels with minimal injury to the overlying epidermis. Pulsed tunable dye lasers also produce selective vascular injury in the abnormal vessels of PWSs, with clinically apparent lightening of the lesions. Both epidermal injury and fibrosis are less severe with this laser treatment than with argon and carbon dioxide laser treatments. Clinical and histologic responses of PWSs treated by argon, CO2, and pulsed yellow dye lasers were compared and followed up for one month in three patients. Although larger and longer-term clinical trials are necessary to fully evaluate this new treatment modality, it appears that pulsed yellow laser radiation offers a more selective, less traumatic, and probably superior form of treatment for PWSs. PMID:3090945

Tan, O T; Carney, J M; Margolis, R; Seki, Y; Boll, J; Anderson, R R; Parrish, J A

1986-09-01

65

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

66

Carbon Dioxide Increases  

NSDL National Science Digital Library

In this problem set, learners will analyze the Keeling Curve showing carbon dioxide concentration in the atmosphere since 1985 to answer a series of questions. Answer key is provided. This is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

67

Atmospheric Carbon Dioxide  

NSDL National Science Digital Library

This figure, the famous Keeling Curve, shows the history of atmospheric carbon dioxide concentrations as directly measured at Mauna Loa, Hawaii. This curve is an essential piece of evidence that shows the increased greenhouse gases that cause recent increases in global temperatures.

Robert A. Rohde

68

Carbon dioxide dangers demonstration model  

USGS Publications Warehouse

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

Venezky, Dina; Wessells, Stephen

2010-01-01

69

A high precision pulsed quantum cascade laser spectrometer for measurements of stable isotopes of carbon dioxide  

Microsoft Academic Search

We describe a prototype instrument using a Peltier cooled quantum cascade laser for precise measurement of stable carbon (13C\\/12C) isotopologue ratios in atmospheric CO2. Using novel optics and signal processing techniques in a compact instrument, we are able to detect the difference between sample and reference with a precision of 0.10\\/00 (2sigma standard error of mean of 11 samples) in

J. B. McManus; D. D. Nelson; J. H. Shorter; R. Jimenez; S. Herndon; S. Saleska; M. Zahniser

2005-01-01

70

Surface and mineral changes of enamel with different remineralizing agents in conjunction with carbon-dioxide laser  

PubMed Central

Aim: The aim of this study was to evaluate the surface/mineral changes on enamel before and after the application of acidulated phosphate fluoride (APF) gel, fluoride enhanced hydroxyapatite gel and propolis in conjunction with carbon-dioxide (CO2) laser. Materials and Methods: Crowns of 40 human maxillary central incisors were collected and were divided into four groups of 10 each: Topical fluoride application only, topical fluoride application followed by CO2 laser irradiation, CO2 laser irradiation followed by topical fluoride application and CO2 laser irradiation before and after topical fluoride application. The 10 crowns in each group was again sectioned into four equal parts of mesio-incisal, disto-incisal, mesio-cervical and disto-cervical sections rendering 40 samples in each group. Each group was again subdivided into four subgroups: Subgroup C - untreated enamel surface (control). Subgroup A - APF gel application, subgroup R - fluoride enhanced hydroxyapatite gel application and subgroup P - propolis application. The surface morphology of the test samples were analyzed by scanning electron microscopy and mineral changes by energy dispersion X-ray spectrophotometer. Results: Total mineral content is maximum in Group 4A (CO2 laser irradiation before and after APF gel application) and calcium/phosphate ratio is highest in Group 4R (CO2 laser irradiation before and after Remin-Pro application). Group 2A (APF gel application followed by CO2 laser irradiation) has the maximum fluoride retention. Conclusion: Laser irradiation of enamel through a topically applied APF gel is effective in the prophylaxis and management of dental caries. PMID:24966758

Mohan, Ajit George; Ebenezar, A. V. Rajesh; Ghani, Mohamed Fayas; Martina, Leena; Narayanan, Ashwin; Mony, Bejoy

2014-01-01

71

CARBON DIOXIDE FIXATION.  

SciTech Connect

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

FUJITA,E.

2000-01-12

72

Modeling Carbon Dioxide Levels  

NSDL National Science Digital Library

In this activity students will explore levels of Carbon Dioxide ( C02) in the atmosphere over time. There is concern that levels of C02 are rising; and finding a good mathematical model for CO2 levels is an important part of determining if this is attributable to human technology. Students draw a scatter plot, choose two points to create a linear model for the data, then use the model to make predictions.

2009-01-01

73

The Effect of Carbon Dioxide (CO2) Laser on Sandblasting with Large Grit and Acid Etching (SLA) Surface  

PubMed Central

Introduction: The purpose of this study was to investigate the effect of 6W power Carbon Dioxide Laser (CO2) on the biologic compatibility of the Sandblasting with large grit and acid etching (SLA) titanium discs through studying of the Sarcoma Osteogenic (SaOS-2) human osteoblast-like cells viability. Methods: Sterilized titanium discs were used together with SaOS-2 human osteoblast-like cells. 6 sterilized SLA titanium discs of the experimental group were exposed to irradiation by CO2 laser with a power of 6W and 10.600nm wavelength, at fixed frequency of 80Hz during 45 seconds in both pulse and non-contact settings. SaOS-2 human osteoblast-like cells were incubated under 37°C in humid atmosphere (95% weather, 5% CO2) for 72 hours. MTT test was performed to measure the ratio level of cellular proliferation. Results: The results indicated that at 570nm wavelength, the 6W CO2 laser power have not affected the cellular viability. Conclusion: CO2 laser in 6w power has had no effect on the biologic compatibility of the SLA titanium surface

Foroutan, Tahereh; Ayoubian, Nader

2013-01-01

74

Long-term Followup of Treatment of Peyronie's Disease with Plaque Incision, Carbon Dioxide Laser Plaque Ablation and Placement of a Deep Dorsal Vein Patch Graft  

Microsoft Academic Search

Numerous surgical therapies have been used for Peyronie's disease in patients who maintain potency. We report on incision and carbon dioxide laser ablation of Peyronie's plaque combined with a deep dorsal vein patch graft in the treatment of 6 men (mean age 57 years). The chief indication for surgery was curvature interfering with intromission, with voiding difficulty being a secondary

Edward D. Kim; Kevin T. McVary

1995-01-01

75

The carbon dioxide laser: an alternative surgery technique for the treatment of common cutaneous tumors in dogs  

PubMed Central

Background Tumors of the skin and subcutaneous tissue are the largest group of canine neoplasms. Total excision is still the most effective method for treatment of these skin tumors. For its universal properties the carbon dioxide (CO2) laser appears to be an excellent surgical instrument in veterinary surgery. Laser techniques are alternatives to traditional methods for the surgical management of tumors. The aim of this study was to compare various types of laser techniques in skin oncologic surgery: excision, ablation and mixed technique and to suggest which technique of CO2 laser procedure is the most useful in particular case of tumors in dogs. Findings The study was performed on 38 privately-owned dogs with total number of 40 skin tumors of different type removed by various CO2 laser operation techniques from 2010–2013. The treatment effect was based on the surgical wound evaluation, the relative time of healing and possible local recurrence of the tumor after 3 months post surgery. Local recurrence was observed in two cases. The study showed that in 30 cases time needed for complete resection of lesions was less than 10 minutes. Time of healing was longer than 12 days in 6 cases (42.8%) with tumor excision and in 14 cases (87.5%) where excision with ablation technique was performed. Conclusions The advantages of the CO2 laser surgery were better hemostasis, precision of working, non-contact dissection, less instruments at the site of operation and minimum traumatization of the surrounding tissues. PMID:24393628

2014-01-01

76

Comparative and quantitative study of neutral debris emanated from tin plasmas produced by neodymium-doped yttrium-aluminum-garnet and carbon dioxide laser pulses  

SciTech Connect

Amount of neutral debris emanated from extreme ultraviolet light source must be minimized to maximize its lifetime. Emanation of neutral atomic debris was experimentally investigated using laser-induced-fluorescence technique for carbon dioxide (CO{sub 2}, 10.6 {mu}m in wavelength) and Nd-doped yttrium-aluminum-garnet (Nd:YAG, 1.064 {mu}m) lasers irradiated tin foils. Total number of neutral atomic debris from CO{sub 2} laser-irradiated tin foils was 1/100 times smaller than that from Nd:YAG irradiated ones. Competitiveness of CO{sub 2} laser was revealed in terms of debris mitigation.

Matsuoka, Yuji; Nakai, Yuki; Fujioka, Shinsuke; Maeda, Shinsuke; Shimomura, Masashi; Nishimura, Hiroaki [Institute of Laser Engineering, Osaka University, 2-6 Yamada-Oka, Osaka 565-0871 (Japan); Shimada, Yoshinori; Sunahara, Atsushi [Institute for Laser Technology, Osaka University, 2-6 Yamada-Oka, Osaka 565-0871 (Japan); Yoshida, Minoru [Department of Electronics and Electronic Engineering, Kinki University, 3-4-1 Kowakae, Osaka 577-8502 (Japan)

2010-09-13

77

Use of Zernike polynomials and interferometry in the optical design and assembly of large carbon-dioxide laser systems  

SciTech Connect

This paper describes the need for non-raytracing schemes in the optical design and analysis of large carbon-dioxide lasers like the Gigawatt, Gemini, and Helios lasers currently operational at Los Alamos, and the Antares laser fusion system under construction. The scheme currently used at Los Alamos involves characterizing the various optical components with a Zernike polynomial set obtained by the digitization of experimentally produced interferograms of the components. A Fast Fourier Transform code then propagates the complex amplitude and phase of the beam through the whole system and computes the optical parameters of interest. The analysis scheme is illustrated through examples of the Gigawatt, Gemini, and Helios systems. A possible way of using the Zernike polynomials in optical design problems of this type is discussed. Comparisons between the computed values and experimentally obtained results are made and it is concluded that this appears to be a valid approach. As this is a review article, some previously published results are also used where relevant.

Viswanathan, V.K.

1981-01-01

78

Carbon dioxide sequestration by mineral carbonation  

Microsoft Academic Search

The increasing atmospheric carbon dioxide (CO2) concentration, mainly caused by fossil fuel combustion, has lead to concerns about global warming. A possible technology that can contribute to the reduction of carbon dioxide emissions is CO2 sequestration by mineral carbonation. The basic concept behind mineral CO2 sequestration is the mimicking of natural weathering processes in which calcium or magnesium containing minerals

W. J. J. Huijgen; R. N. J. Comans

2007-01-01

79

Carbon Dioxide Reduction Through Urban Forestry  

E-print Network

Carbon Dioxide Reduction Through Urban Forestry: Guidelines for Professional and Volunteer Tree; Simpson, James R. 1999. Carbon dioxide reduction through urban forestry of Agriculture; 237 p. Carbon dioxide reduction through urban forestry--Guidelines for professional and volunteer

Standiford, Richard B.

80

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

81

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

82

Ex vivo investigations of laser auricular cartilage reshaping with carbon dioxide spray cooling in a rabbit model  

PubMed Central

Laser cartilage reshaping (LCR) with cryogen spray cooling is a promising modality for producing cartilage shape change while reducing cutaneous thermal injury. However, LCR in thicker tissues, such as auricular cartilage, requires higher laser power, thus increasing cooling requirements. To eliminate the risks of freeze injury characteristic of high cryogen spray pulse rates, a carbon dioxide (CO2) spray, which evaporates rapidly from the skin, has been proposed as the cooling medium. This study aims to identify parameter sets which produce clinically significant reshaping while producing minimal skin thermal injury in LCR with CO2 spray cooling in ex vivo rabbit auricular cartilage. Excised whole rabbit ears were mechanically deformed around a cylindrical jig and irradiated with a 1.45-?m wavelength diode laser (fluence 12–14 J/cm2 per pulse, four to six pulse cycles per irradiation site, five to six irradiation sites per row for four rows on each sample) with concomitant application of CO2 spray (pulse duration 33–85 ms) to the skin surface. Bend angle measurements were performed before and after irradiation, and the change quantified. Surface temperature distributions were measured during irradiation/cooling. Maximum skin surface temperature ranged between 49.0 to 97.6 °C following four heating/cooling cycles. Significant reshaping was achieved with all laser dosimetry values with a 50–70 °C difference noted between controls (no cooling) and irradiated ears. Increasing cooling pulse duration yielded progressively improved gross skin protection during irradiation. CO2 spray cooling may potentially serve as an alternative to traditional cryogen spray cooling in LCR and may be the preferred cooling medium for thicker tissues. Future studies evaluating preclinical efficacy in an in vivo rabbit model are in progress. PMID:23307439

Wu, Edward C.; Sun, Victor; Manuel, Cyrus T.; Protsenko, Dmitriy E.; Jia, Wangcun; Nelson, J. Stuart; Wong, Brian J. F.

2014-01-01

83

A high precision pulsed quantum cascade laser spectrometer for measurements of stable isotopes of carbon dioxide  

E-print Network

A high precision pulsed quantum cascade laser spectrometer for measurements of stable isotopes form 2 July 2005) We describe a prototype instrument using a Peltier cooled quantum cascade laser diode lasers. The application of pulsed near room-temperature quantum cascade lasers to this demanding

Saleska, Scott

84

Sampling Carbon Dioxide  

NSDL National Science Digital Library

In this lab activity, student teams hypothesize which source has a greater becomes CO² concentration: their breath, auto exhaust, or air in the classroom. They test gas samples from each of these sources, plot data, and hypothesize about the respective role engine exhaust and animal respiration play in contemporary climate change. The lab procedures require Bromthymol Blue indicator solution (BTB), household ammonia, vinegar, and balloons. Links to videos supporting the investigations are provided. This activity is supported by a textbook chapter, "How is Carbon Dioxide Measured?," part of the unit, Climate Change, in Global Systems Science (GSS), an interdisciplinary course for high school students that emphasizes how scientists from a wide variety of fields work together to understand significant problems of global impact.

85

Geologic Sequestration of Carbon Dioxide  

NASA Astrophysics Data System (ADS)

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

Benson, S. M.

2003-04-01

86

Scaling Studies of Blackbody-Pumped Carbon-Dioxide Lasers Using Gaussian and Waveguide Cavities  

Microsoft Academic Search

A large scale pulsed laser system with heated tantalum foils as the blackbody pumping source was built in the laboratory. A deeper understanding of the physics and the scaling factors of the blackbody pumped CO _2 laser has been achieved through parametric scaling studies using this system. Numerical analysis is also performed for computing pumping power and laser gain. Theoretical

Jim Jih-Chyun Chang

1989-01-01

87

Safe and Effective One-Session Fractional Skin Resurfacing Using a Carbon Dioxide Laser Device in Super-Pulse Mode: A Clinical and Histologic Study  

Microsoft Academic Search

Carbon dioxide (CO2) laser ablative fractional resurfacing produces skin damage, with removal of the epidermis and variable portions of the dermis\\u000a as well as associated residual heating, resulting in new collagen formation and skin tightening. The nonresurfaced epidermis\\u000a helps tissue to heal rapidly, with short-term postoperative erythema. The results for 40 patients (8 men and 32 women) after\\u000a a single

Mario A. Trelles; Michael Shohat; Fernando Urdiales

2011-01-01

88

Reducing carbon dioxide to products  

DOEpatents

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

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

2014-09-30

89

NASA Satellite Sees Carbon Dioxide  

NSDL National Science Digital Library

In this problem set, learners will analyze a map of atmospheric carbon dioxide derived from satellite data. Answer key is provided. This is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

90

Carbon Dioxide and Ocean Acidification  

NSDL National Science Digital Library

Demonstrates the affect of increased dissolved carbon dioxide on water pH using a cheap, non-toxic acid/base indicator. Students bubble breath through a straw into red cabbage juice and note the color change.

Chris Lewis

91

Recuperative supercritical carbon dioxide cycle  

DOEpatents

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

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

2014-11-18

92

New technique for feline carbon dioxide laser onychectomy by resection of the redundant epidermis of the ungual crest  

NASA Astrophysics Data System (ADS)

A new technique for feline carbon dioxide laser onychectomy can further minimize postoperative pain and complications in any age animal. This procedure is accomplished by resection of the redundant epidermis over the ungual crest. Resection of the redundant epidermis allows complete dissection and removal of the claw from a strictly cranio-dorsal approach, thereby minimizing trauma to the surrounding tissues and post- operative complications. The laser setting is preferred at four to six watts continuous power. The epidermis of the ungual crest is resected in a circumferential manner at its most distal edge. This tissue is pushed proximally over the ungual crest. A second circumferential incision is made 3 mm proximal to the first incision. Deeper subcutaneous fascia is also pushed proximally over the ungual crest. An incision of the extensor tendon is made at its insertion on the ungual crest keeping the redundant epidermis proximal to this incision. The incision through the extensor tendon is continued deeper to the synovium of PII and PIII. Gentle traction in a palmar direction will disarticulate the joint space between PII and PIII. Incisions into the lateral and medial collateral ligaments from a cranio-dorsal origin in palmar direction further disarticulate the joint. Care must be exercised to preserve all epidermal tissue lying immediately adjacent to the collateral ligaments. Continual palmar traction will expose the base of PIII and the insertion of the flexor tendon. A dorsal incision is made into the flexor tendon in a palmar direction. Extreme palmar rotation of PIII will allow the dissection of the subcutaneous tissue of the pad from PIII. The redundant epidermal tissue will now cover the majority of the onychectomy site. No sutures or tissue adhesive are advised.

Young, William P.

2000-05-01

93

Experience with a carbon dioxide laser for removal of benign oral soft-tissue lesions.  

PubMed

Fifty-six patients with 86 benign oral soft-tissue lesions were treated with CO2 laser surgery during a period of 48 months. The lesions removed included hyperplasias, papillomas, haemangiomas, mucoceles, lichen planus, fibromas, condylomas and lingual frenula. All clinical diagnoses except that of lingual frenulum were verified histopathologically. The lesions were excised using the laser to obtain biopsy specimens. However, in some cases it was felt more appropriate to excise biopsy material from the most characteristic part of the lesion first, then to destroy the rest of the lesion. Treatment was undertaken in one session under local anaesthesia without premedication. No patient received antibiotics or anti-inflammatory drugs after operation. The lesions were operated on freehand using a handpiece and laser power ranging from 6 to 10 W in continuous mode. The beam in focus was 0.2 mm in diameter, which allowed fine dissection. There was no bleeding from the laser wounds, and no need for suturing. Removal of the lesions using the laser was fast and easy. Healing took place with minimal post-operative discomfort, and without visible scarring. The results of this study suggest that use of a CO2 laser leads to a level of precision similar to and sometimes better than that of a scalpel in the treatment of benign oral soft-tissue lesions. The laser beam could be used to obtain biopsy specimens without tissue destruction. PMID:1470632

Luomanen, M

1992-01-01

94

Transdermal delivery of three vitamin C derivatives by Er:YAG and carbon dioxide laser pretreatment.  

PubMed

The objective of this study was to investigate the effects of two lasers (Er:YAG and CO2) in enhancing skin permeation of three vitamin C derivatives, L-ascorbic acid 2-phosphate sesquimagnesium salt (MAP-1), magnesium L-ascorbic acid-2-phosphate (MAP-2), and 2-phospho-L-ascorbic acid trisodium salt (SAP). Dorsal skin of 1-week-old pathogen-free pigs was used for this in vitro study. Changes in permeation in laser-treated skin treated by the lasers were examined by confocal scanning electron microscopy. Transdermal flux of vitamin C derivatives was examined with a Franz diffusion cell. Fluxes of MAP-1, MAP-2, and SAP across Er:YAG laser-treated skin were 15-27-fold, 48-123-fold, and 22-56-fold higher, respectively, than their fluxes across intact skin. The fluxes of MAP-1, MAP-2, and SAP across CO2 laser-treated skin were 28-36-fold, 116-156-fold, and 79-102-fold higher, respectively, than their fluxes across intact skin. Optimal fluency for the Er:YAG laser was 3.8 J/cm(2) for MAP-1 and 5 J/cm(2) for MAP-2 and SAP. Optimal fluency for the CO2 laser was 5 W for all three derivatives. In conclusion, optimal fluency for all derivatives was 5 W for the CO2 laser and 3.8 to 5 J/cm(2) for the Er:YAG laser. PMID:22825318

Huang, Chun-Hsun; Sung, Hsin-Ching; Hsiao, Chien-Yu; Hu, Sindy; Ko, Yu-Shien

2013-05-01

95

Carbon dioxide laser ablation with immediate autografting in a full-thickness porcine burn model.  

PubMed Central

OBJECTIVE: To compare the long-term clinical and histologic outcome of immediate autografting of full-thickness burn wounds ablated with a high-power continuous-wave CO2 laser to sharply débrided wounds in a porcine model. SUMMARY BACKGROUND DATA: Continuous-wave CO2 lasers have performed poorly as tools for burn excision because the large amount of thermal damage to viable subeschar tissues precluded successful autografting. However, a new technique, in which a high-power laser is rapidly scanned over the eschar, results in eschar vaporization without significant damage to underlying viable tissues, allowing successful immediate autografting. METHODS: Full-thickness paravertebral burn wounds measuring 36 cm2 were created on 11 farm swine. Wounds were ablated to adipose tissue 48 hours later using either a surgical blade or a 150-Watt continuous-wave CO2 laser deflected by an x-y galvanometric scanner that translated the beam over the tissue surface, removing 200 microm of tissue per scan. Both sites were immediately autografted and serially evaluated clinically and histologically for 180 days. RESULTS: The laser-treated sites were nearly bloodless. The mean residual thermal damage was 0.18+/-0.05 mm. The mean graft take was 96+/-11% in manual sites and 93+/-8% in laser sites. On postoperative day 7, the thickness of granulation tissue at the graft-wound bed interface was greater in laser-debrided sites. By postoperative day 180, the manual and laser sites were histologically identical. Vancouver scar assessment revealed no differences in scarring at postoperative day 180. CONCLUSIONS: Long-term scarring, based on Vancouver scar assessments and histologic evaluation, was equivalent at 6 months in laser-ablated and sharply excised sites. Should this technology become practical, the potential clinical implications include a reduction in surgical blood loss without sacrifice of immediate engraftment rates or long-term outcome. Images Figure 1. Figure 2. Figure 3. Figure 4. PMID:9712572

Glatter, R D; Goldberg, J S; Schomacker, K T; Compton, C C; Flotte, T J; Bua, D P; Greaves, K W; Nishioka, N S; Sheridan, R L

1998-01-01

96

Design of a high pulse repitition frequency carbon dioxide laser for processing high damage threshold materials  

NASA Astrophysics Data System (ADS)

The absence of an applications led design philosophy has compromised both the development of laser source technology and its effective implementation into manufacturing technology in particular. For example, CO2 lasers are still incapable of processing classes of refractory and non-ferrous metals. Whilst the scope of this paper is restricted to high power CO2 lasers; the design methodology reported herein is applicable to source technology in general, which when exploited, will effect an expansion of applications. The CO2 laser operational envelope should not only be expanded to incorporate high damage threshold materials but also offer a greater degree of controllability. By a combination of modelling and experimentation the requisite beam characteristics, at the workpiece, were determined then utilised to design the Laser Manufacturing System. The design of sub-system elements was achieved by a combination of experimentation and simulation which benefited from a comprehensive set of software tools. By linking these tools the physical processes in the laser - electron processes in the plasma, the history of photons in the resonator, etc. - can be related, in a detailed model, to the heating mechanisms in the workpiece.

Chatwin, Christopher R.; McDonald, Donald W.; Scott, Brian F.

1989-07-01

97

Molecular Structure of Carbon Dioxide  

NSDL National Science Digital Library

Carbon dioxide was first described in the 17th century by Jan Baptist van Helmont, a Belgium chemist. The chemical CO2 is released into the atmosphere when carbon-containing fossil fuels like oil, natural gas, and coal are burned in air. It is also produced by various microorganisms in fermentation and is breathed out by animals. Plants absorb carbon dioxide during photosynthesis, using both the carbon and the oxygen to construct carbohydrates. Every year the amount of CO2 in the atmosphere is increasing. CO2 build-up in the atmosphere is caused by deforestation, therefore reducing the number of trees available to absorb CO2. Excess CO2 in the environment causes Global Warming and the Greenhouse Effect. It is also toxic to humans since inhalation of large amounts of CO2 can cause suffocation. Some beverages, such as beer and sparkling wine contain carbon dioxide as a result of fermentation.

2002-08-15

98

Chondrodermatitis nodularis chronica helicis. Successful treatment with the carbon dioxide laser.  

PubMed

Chondrodermatitis nodularis chronica helicis is a painful, persistent, or recurrent inflammatory lesion involving the cartilage and skin of the external ear. These lesions are resistant to many therapeutic modalities and often recur even after surgical excision. The CO2 laser was used to vaporize the cutaneous nodules and involved cartilage. The wounds were allowed to heal with only minimal care using hydrogen peroxide cleansing and applications of topical antibiotic ointment. Twelve lesions have been treated with no recurrences after 2 to 15 months. There have been no complications or infections following laser surgery. The pain from these lesions is gone immediately following laser surgery. Healing with excellent cosmetic results is complete usually within 3 to 4 weeks. PMID:1757647

Taylor, M B

1991-11-01

99

The Tea-Carbon Dioxide Laser as a Means of Generating Ultrasound in Solids  

NASA Astrophysics Data System (ADS)

Available from UMI in association with The British Library. Requires signed TDF. The aim of this thesis is to characterise the interaction between pulsed, high power, 10.6 mu m radiation and solids. The work is considered both in the general context of laser generation of ultrasound and specifically to gain a deeper understanding of the interaction between a laser supported plasma and a solid. The predominant experimental tools used are the homodyne Michelson interferometer and a range of electromagnetic acoustic transducers. To complement the ultrasonic data, various plasma inspection techniques, such as high speed, streak camera photography and reflection photometry, have been used to correlate the plasma properties with those of the ultrasonic transients. The work involving the characterisation of a laser supported plasma with a solid, which is based on previous experimental and theoretical analysis, gives an increased understanding of the plasma's ultrasonic generation mechanism. The ability to record the entire plasma-sample interaction, time history yields information of the internal dynamics of the plasma growth and shock wave generation. The interaction of the radiation with a solid is characterised in both the plasma breakdown and non-breakdown regimes by a wide ultrasonic source. The variation in source diameter enables the transition from a point to a near planar ultrasonic source to be studied. The resultant ultrasonic modifications are examined in terms of the wave structure and the directivity pattern. The wave structure is analysed in terms of existing wide source, bulk wave theories and extended to consider the effects on surface and Lamb waves. The directivity patterns of the longitudinal and shear waves are analysed in terms of top-hat and non -uniform source profiles, giving additional information into the radiation-solid interaction. The wide, one dimensional source analysis is continued to a two dimensional, extended ultrasonic source, generated on non-metals by the optical penetration of radiation within the target. The generation of ultrasound in both metals and non-metals, using the CO_2 laser, is shown to be an efficient process and may be employed almost totally non-destructively. Such a laser may therefore be used effectively on a greatly enhanced range of materials than those tested to-date via laser generation, resulting in the increased suitability of the laser technique within the field of Non Destructive Testing.

Taylor, Gregory Stuart

1990-01-01

100

Infrared Pulse-laser Long-path Absorption Measurement of Carbon Dioxide Using a Raman-shifted Dye Laser  

NASA Technical Reports Server (NTRS)

A pulsed laser source is effective in infrared laser long-path absorption measurements when the optical path length is very long or the reflection from a hard target is utilized, because higher signal-to-noise ratio is obtained in the detection of weak return signals. We have investigated the performance of a pulse-laser long-path absorption system using a hydrogen Raman shifter and a tunable dye laser pumped by a Nd:YAG laser, which generates second Stokes radiation in the 2-micron region.

Minato, Atsushi; Sugimoto, Nobuo; Sasano, Yasuhiro

1992-01-01

101

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

102

In vivo study of necrosis on the liver tissue of Wistar rats: a combination of photodynamic therapy and carbon dioxide laser ablation  

NASA Astrophysics Data System (ADS)

Photodynamic therapy (PDT) is known to be limited to applications in large volume tumors due to its limited penetration. Therefore, a combination of PDT and carbon dioxide (CO2) laser ablation may constitute a potential protocol to destroy bulk tumors because it involves an association of these two techniques allowing the removal of visible lesions with a high selectivity of destruction of remnant tumors. The main aim of this study is to investigate the most appropriate procedure to combine use of a CO2 laser and PDT on livers of healthy rats, and to analyze different techniques of this treatment using three types of photosensitizers (PSs). Forty eight animals were separated to form six groups: (1) only CO2 laser ablation, (2) drug and CO2 laser ablation, (3) only PDT, (4) drug and light (PDT) followed by CO2 laser ablation, (5) ablated with CO2 laser followed by PDT, and (6) drug followed by CO2 laser ablation and light. For each group, three types of photosensitization were used: topical 5-aminolevulinic acid (ALA), intravenous ALA and intravenous Photogem®. Thirty hours after the treatments, the animals were sacrificed and the livers removed. The depth of necrosis was analyzed and measured, considering microscopic and macroscopic aspects. The results show that the effects of the PDT were considerably enhanced when combined with CO2 laser ablation, especially when the PDT was performed before the CO2 laser ablation.

Rego, R. F.; Nicolodelli, G.; Araujo, M. T.; Tirapelli, L. F.; Araujo-Moreira, F. M.; Bagnato, V. S.

2013-07-01

103

Mitigation of Laser Damage Growth in Fused Silica NIF Optics with a Galvanometer Scanned Carbon Dioxide Laser  

SciTech Connect

Economic operation of the National Ignition Facility at the Lawrence Livermore National Laboratory depends on controlling growth of laser damage in the large, high cost optics exposed to UV light at 351 nm. Mitigation of the growth of damage sites on fused silica surfaces greater than several hundred microns in diameter has been previously reported by us using galvanometer scanning of a tightly focused 10.6 {micro}m CO{sub 2} laser spot over an area encompassing the laser damage. Further investigation revealed that fused silica vapor re-deposited on the surface as ''debris'' led to laser damage at unexpectedly low fluences when exposed to multiple laser shots at 351 nm. Additionally, laser power and spatial mode fluctuations in the mitigation laser led to poor repeatability of the process. We also found that the shape of the mitigation pit could produce downstream intensification that could damage other NIF optics. Modifications were made to both the laser system and the mitigation process in order to address these issues. Debris was completely eliminated by these changes, but repeatability and downstream intensification issues still persist.

Bass, I L; Draggoo, V; Guss, G M; Hackel, R P; Norton, M A

2006-04-06

104

Carbon Dioxide - Our Common "Enemy"  

NASA Technical Reports Server (NTRS)

Health effects of brief and prolonged exposure to carbon dioxide continue to be a concern for those of us who manage this pollutant in closed volumes, such as in spacecraft and submarines. In both examples, considerable resources are required to scrub the atmosphere to levels that are considered totally safe for maintenance of crew health and performance. Defining safe levels is not a simple task because of many confounding factors, including: lack of a robust database on human exposures, suspected significant variations in individual susceptibility, variations in the endpoints used to assess potentially adverse effects, the added effects of stress, and the fluid shifts associated with micro-gravity (astronauts only). In 2007 the National Research Council proposed revised Continuous Exposure Guidelines (CEGLs) and Emergency Exposure Guidelines (EEGLs) to the U.S. Navy. Similarly, in 2008 the NASA Toxicology Group, in cooperation with another subcommittee of the National Research Council, revised Spacecraft Maximum Allowable Concentrations (SMACs). In addition, a 1000-day exposure limit was set for long-duration spaceflights to celestial bodies. Herein we examine the rationale for the levels proposed to the U.S. Navy and compare this rationale with the one used by NASA to set its limits. We include a critical review of previous studies on the effects of exposure to carbon dioxide and attempt to dissect out the challenges associated with setting fully-defensible limits. We also describe recent experiences with management of carbon dioxide aboard the International Space Station with 13 persons aboard. This includes the tandem operations of the Russian Vozduk and the U.S. Carbon Dioxide Removal System. A third removal system is present while the station is docked to the Shuttle spacecraft, so our experience includes the lithium hydroxide system aboard Shuttle for the removal of carbon dioxide. We discuss strategies for highly-efficient, regenerable removal of carbon dioxide that could meet the 1000-day SMAC of 0.5%, which would apply to long-duration voyages to Mars.

James, John T.; Macatangay, Ariel

2009-01-01

105

Solid-State 2-Micron Laser Transmitter Advancement for Wind and Carbon Dioxide Measurements From Ground, Airborne, and Space-Based Lidar Systems  

NASA Technical Reports Server (NTRS)

NASA Langley Research Center has been developing 2-micron lidar technologies over a decade for wind measurements, utilizing coherent Doppler wind lidar technique and carbon dioxide measurements, utilizing Differential Absorption Lidar (DIAL) technique. Significant advancements have been made towards developing state-of-the-art technologies towards laser transmitters, detectors, and receiver systems. These efforts have led to the development of solid-state lasers with high pulse energy, tunablility, wavelength-stability, and double-pulsed operation. This paper will present a review of these technological developments along with examples of high resolution wind and high precision CO2 DIAL measurements in the atmosphere. Plans for the development of compact high power lasers for applications in airborne and future space platforms for wind and regional to global scale measurement of atmospheric CO2 will also be discussed.

Singh, Upendra N.; Kavaya, Michael J.; Koch, Grady; Yu, Jirong; Ismail, Syed

2008-01-01

106

Process for sequestering carbon dioxide and sulfur dioxide  

DOEpatents

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

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

2009-10-20

107

Carbon dioxide transport over complex terrain  

USGS Publications Warehouse

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

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

2004-01-01

108

Observation of in vivo morphologic changes after carbon dioxide ablative fractional laser in a mouse model using noninvasive imaging modalities and comparison with histologic examination.  

PubMed

Ablative fractional carbon dioxide (CO2) lasers have been widely used for several types of cosmetic dermatosis. A number of previous studies have evaluated this technique in animals or human beings by observing morphologic changes using an invasive modality such as skin biopsy. In this study, we assessed in vivo skin changes after CO2 ablative fractional laser treatment in a mouse model using noninvasive imaging modalities (Folliscope(®) and Visioscan 98(®)), and each results was compared with data from histologic examination. An ablative fractional CO2 laser was applied with different pulse energy between 7 to 35 mJ/microspot. As results of above methods, we also confirmed that the CO2 ablative fractional laser generated injuries with increasing width and depth with increasing pulse energy. Although numerous papers have described application of this laser in vivo skin specimens, our study evaluated the feasibility of using relative noninvasive imaging modalities for assessing the outcome of laser ablation. Based on our data, we suggest that these technologies may be useful alternative modalities for assessing laser ablation that are easier to perform and less invasive than skin biopsy. PMID:25041574

Yoo, Kwang Ho; Kwon, Tae Rin; Kim, So Young; Song, Yi Seop; Cheon, Young Sook; Kim, Yu Mi; Yeo, In Kwon; Ko, Eun Jung; Li, Kapsok; Kim, Myeung Nam; Kim, Beom Joon

2014-01-01

109

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.

110

Photolytical Generation of Carbon Dioxide  

Microsoft Academic Search

Carbon dioxide has been found by Cassini VIMS throughout the Saturnian system in locations such as Iapetus' equator where the temperature is too high for it to remain as free ice for more than a few hundred years. We suggest that the 4.26 micron absorption feature found on Iapetus and Hyperion (that has been attributed to complexed CO2) is the

E. E. Palmer; R. H. Brown

2008-01-01

111

Infrared planar laser-induced fluorescence imaging and applications to imaging of carbon monoxide and carbon dioxide  

NASA Astrophysics Data System (ADS)

This dissertation introduces infrared planar laser- induced fluorescence (IR PLIF) techniques for visualization of species that lack convenient electronic transitions and are therefore unsuitable for more traditional electronic PLIF measurements. IR PLIF measurements can generate high signal levels that scale linearly with both laser energy and species concentration, thereby demonstrating advantages over Raman and multiphoton PLIF techniques. IR PLIF is shown to be a straightforward and effective tool for visualization of CO and CO2 in reactive flows. The slow characteristic times of vibrational relaxation and the large mole fractions of CO and CO2 in typical flows lead to high IR PLIF signal levels, despite the low emission rates typical of vibrational transitions. Analyses of rotational energy transfer (RET) and vibrational energy transfer (VET) show that excitation schemes in either linear (weak) or saturated (strong) limits may be developed, with the fluorescence collected directly from the laser-excited species or indirectly from bath gases in vibrational resonance with the laser-excited species. Use of short (~1 ?s) exposures (for CO) or short exposures combined with long-pulse, high-pulse-energy excitation (for CO2) minimizes unwanted signal variation due to spatially-dependent VET rates. Results are presented for flows ranging from room- temperature mixing to a benchmark CH4 laminar diffusion flame. Linear excitation is appropriate for CO due to its slow vibrational relaxation. However, linear excitation is not well-suited for CO2 imaging due to fast H 2O-enhanced VET processes and the attendant difficulty in interpreting the resulting signal. Saturated excitation using a CO2 laser (or combined CO2 laser-OPO) technique is most appropriate for CO 2, as it generates high signal and minimizes spatial variations in fluorescence quantum yield. Since IR PLIF is applicable to most IR-active species, it has a high potential for expanding the diagnostic possibilities available to combustion researchers. Such diagnostics might include visualization of the fuel region of lifted flames, CO-formation regions in flames, or exhaust mixing processes in internal combustion engines as applied to residual-induced autoignition.

Kirby, Brian James

112

Electrochemically regenerable carbon dioxide absorber  

NASA Technical Reports Server (NTRS)

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

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

1979-01-01

113

Carbon Dioxide Removal via Passive Thermal Approaches  

NASA Technical Reports Server (NTRS)

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

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

2011-01-01

114

VAPOR + LIQUID EQUILIBRIUM OF WATER, CARBON DIOXIDE, AND THE BINARY SYSTEM WATER + CARBON DIOXIDE FROM  

E-print Network

) were used to describe the properties of the pure substances. The vapor pressures of water and carbonVAPOR + LIQUID EQUILIBRIUM OF WATER, CARBON DIOXIDE, AND THE BINARY SYSTEM WATER + CARBON DIOXIDE the vapor-liquid equilibrium of water (between 323 and 573 K), carbon dioxide (between 230 and 290 K

115

Carbon dioxide review 1982  

SciTech Connect

The buildup of CO/sub 2/ is a reality, monitored with increasing precision since 1957 and inferred for much earlier dates. A statistical section gives the monitored values to 1980, as well as a review of a long series of measurements made at Mauna Loa by the pioneers of such monitoring, Charles D. Keeling, Robert B. Bacastow, and Timothy P. Whorf. The book discusses internal transport processes in the ocean, of ocean-atmosphere interaction, of the magnitude of forest and soil carbon wastage, of the future course of fossil-fuel consumption. Yet something else emerges, too: if the CO/sub 2/ buildup continues; if the big general circulation models are right about its impact on climate, and if we have not miscalculated the potential role of the oceans, then we face a climatic change in the next century and a half like nothing the post-glacial world, and hence civilized humanity, has seen.

Clark, W.C. (ed.)

1982-01-01

116

The Change in Carbon Dioxide Levels  

NSDL National Science Digital Library

In this lesson students discover that ice cores can help us learn not only the temperature of the Earth in times past, but also the amount of Carbon Dioxide trapped in the air bubbles in the ice. This activity uses as source data a plot of each versus time, and asks the students to plot the Temperature variable versus the other variable which is the Carbon Dioxide content. Students can fit the data to a line y = mx + b to see how changes in Temperature and related to changes in Carbon Dioxide. After they make a graph of Carbon Dioxide concentration as a function of time, they will learn about linear trends in the data, as well as the annual variation of Carbon Dioxide and will then predict the level of Carbon Dioxide in a future year from the data.

117

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

118

Carbon Dioxide Capture from Coal-Fired  

E-print Network

Carbon Dioxide Capture from Coal-Fired Power Plants: A Real Options Analysis May 2005 MIT LFEE 2005 are valued using the "real options" valuation methodology in an uncertain carbon dioxide (CO2) price support for the work was provided by the Carbon Sequestration Initiative. The authors acknowledge Linda Ye

119

Carbon Cycle: Exchanging Carbon Dioxide between the Atmosphere and Ocean  

NSDL National Science Digital Library

This lab investigates the exchange of carbon dioxide between the atmosphere and the ocean's surface. It is based on the fact that carbon dioxide dissolves in the ocean and provides the source of that plants and plankton living in the ocean rely on for photosynthesis. Students will discover that the amount of carbon dioxide the ocean can contain depends on the temperature of the water and its salinity (whether it is sea water or fresh water) and that cold water can hold more carbon dioxide in solution than warm water. They will observe that when carbon dioxide dissolves in water, it forms carbonic acid which makes the water acidic, and they will test for the acidity caused by the presence of dissolved carbon dioxide using Universal Indicator, which turns yellow when the solution is acidic. This activity tests whether sea water or fresh water absorbs more carbon dioxide.

120

Experimental carbon dioxide laser brain lesions and intracranial dynamics. Part 2. Effect on brain water content and its response to acute therapy  

SciTech Connect

Experimental brain lesions were created over the left parietooccipital cortex of the albino rabbit through the intact dura mater with high radiating carbon dioxide laser energy. The brain water content was studied 2, 6, and 24 hours after the insult. Another two groups of animals received acute therapy with either dexamethasone (1 mg/kg) or furosemide (1 mg/kg). In all groups, Evans blue extravasation uniformly extended from the impact crater into the surrounding white matter. The brain water content in the gray matter was elevated from the control value by 2 hours after impact and remained elevated at 6 and 24 hours. The white matter brain water content did not increase until 6 hours after impact and remained elevated in the 24-hour group. After dexamethasone treatment, there was a significant decrease of water in the gray matter, but not in the white matter. With furosemide therapy, there was no reduction of gray or white matter brain water.

Tiznado, E.G.; James, H.E.; Moore, S.

1985-04-01

121

46 CFR 131.817 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Carbon dioxide warning signs. 131.817 ...and Emergency Equipment § 131.817 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space...

2014-10-01

122

46 CFR 193.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Carbon dioxide storage. 193.15-20...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-20 Carbon dioxide storage. (a)...

2014-10-01

123

46 CFR 108.431 - Carbon dioxide systems: General.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Carbon dioxide systems: General. 108.431...EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a)...

2014-10-01

124

46 CFR 169.565 - Fixed carbon dioxide system.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Fixed carbon dioxide system. 169.565 Section 169...Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space...

2014-10-01

125

46 CFR 196.37-8 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Carbon dioxide warning signs. 196.37-8...Emergency Equipment, etc. § 196.37-8 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space...

2014-10-01

126

46 CFR 108.626 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Carbon dioxide warning signs. 108.626 ...Markings and Instructions § 108.626 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space...

2014-10-01

127

46 CFR 78.47-11 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Carbon dioxide warning signs. 78.47-11...Emergency Equipment, Etc. § 78.47-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space...

2014-10-01

128

46 CFR 97.37-11 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Carbon dioxide warning signs. 97.37-11...Emergency Equipment, Etc. § 97.37-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space...

2014-10-01

129

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

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Carbon dioxide, refrigerated liquid. 179...114 and 120) § 179.102-1 Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated liquid...

2014-10-01

130

Silanediol-catalyzed carbon dioxide fixation.  

PubMed

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

Hardman-Baldwin, Andrea M; Mattson, Anita E

2014-12-01

131

Carbon Dioxide for pH Control  

SciTech Connect

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

Wagonner, R.C.

2001-08-16

132

Interglacials, Milankovitch Cycles, and Carbon Dioxide  

E-print Network

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

Gerald E. Marsh

2010-02-11

133

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...

134

Encapsulated liquid sorbents for carbon dioxide capture.  

PubMed

Drawbacks of current carbon dioxide capture methods include corrosivity, evaporative losses and fouling. Separating the capture solvent from infrastructure and effluent gases via microencapsulation provides possible solutions to these issues. Here we report carbon capture materials that may enable low-cost and energy-efficient capture of carbon dioxide from flue gas. Polymer microcapsules composed of liquid carbonate cores and highly permeable silicone shells are produced by microfluidic assembly. This motif couples the capacity and selectivity of liquid sorbents with high surface area to facilitate rapid and controlled carbon dioxide uptake and release over repeated cycles. While mass transport across the capsule shell is slightly lower relative to neat liquid sorbents, the surface area enhancement gained via encapsulation provides an order-of-magnitude increase in carbon dioxide absorption rates for a given sorbent mass. The microcapsules are stable under typical industrial operating conditions and may be used in supported packing and fluidized beds for large-scale carbon capture. PMID:25652243

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

2015-01-01

135

Carbon dioxide sequestration by mineral carbonation  

SciTech Connect

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

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

2003-11-01

136

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

137

Field-based stable isotope analysis of carbon dioxide by mid-infrared laser spectroscopy for carbon capture and storage monitoring.  

PubMed

A newly developed isotope ratio laser spectrometer for CO2 analyses has been tested during a tracer experiment at the Ketzin pilot site (northern Germany) for CO2 storage. For the experiment, 500 tons of CO2 from a natural CO2 reservoir was injected in supercritical state into the reservoir. The carbon stable isotope value (?(13)C) of injected CO2 was significantly different from background values. In order to observe the breakthrough of the isotope tracer continuously, the new instruments were connected to a stainless steel riser tube that was installed in an observation well. The laser instrument is based on tunable laser direct absorption in the mid-infrared. The instrument recorded a continuous 10 day carbon stable isotope data set with 30 min resolution directly on-site in a field-based laboratory container during a tracer experiment. To test the instruments performance and accuracy the monitoring campaign was accompanied by daily CO2 sampling for laboratory analyses with isotope ratio mass spectrometry (IRMS). The carbon stable isotope ratios measured by conventional IRMS technique and by the new mid-infrared laser spectrometer agree remarkably well within analytical precision. This proves the capability of the new mid-infrared direct absorption technique to measure high precision and accurate real-time stable isotope data directly in the field. The laser spectroscopy data revealed for the first time a prior to this experiment unknown, intensive dynamic with fast changing ?(13)C values. The arrival pattern of the tracer suggest that the observed fluctuations were probably caused by migration along separate and distinct preferential flow paths between injection well and observation well. The short-term variances as observed in this study might have been missed during previous works that applied laboratory-based IRMS analysis. The new technique could contribute to a better tracing of the migration of the underground CO2 plume and help to ensure the long-term integrity of the reservoir. PMID:25375020

van Geldern, Robert; Nowak, Martin E; Zimmer, Martin; Szizybalski, Alexandra; Myrttinen, Anssi; Barth, Johannes A C; Jost, Hans-Jürg

2014-12-16

138

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

139

Fractional carbon dioxide laser-assisted drug delivery of topical timolol solution for the treatment of deep infantile hemangioma: a pilot study.  

PubMed

Infantile hemangiomas (IHs) are benign vascular tumors of infancy. Topical timolol has recently been reported to be an effective treatment for superficial IHs, although it failed to have an effect on deep IHs. This prospective study was aimed at evaluating the feasibility of ablative fractional laser-assisted drug delivery for enhancing topical timolol permeation into deep IHs. Nine patients ages 1 to 6 months with deep IHs were enrolled. A fractional carbon dioxide (CO2 ) laser system was applied to the skin surface of deep IHs using the DeepFx mode (25-30 mJ/pulse, 5% density, single pulse) at 1-week intervals. Topical timolol maleate 0.5% ophthalmic solution was applied under occlusion for 30 minutes four to five times per day for an average treatment duration of 14.2 weeks. Clinical improvement was evaluated according to a global score and the Hemangioma Activity Score (HAS). Four patients (44.4%) demonstrated excellent regression, four (44.4%) showed good response, and one (11.1%) experienced moderate regression. The HAS declined from 4.1 ± 0.7 at baseline to 1.7 ± 0.7 at 1 week (p < 0.001) and 1.4 ± 0.7 at 3 months (p = 0.03) after the last treatment procedure. Plasma timolol concentration was not detected in any of the patients after the first administration of topical timolol. No systemic complication or skin side effects were observed in any of the patients. Ablative fractional laser-assisted transdermal delivery of topical timolol is a safe and effective method for the treatment of deep IHs. PMID:24602019

Ma, Gang; Wu, Pinru; Lin, Xiaoxi; Chen, Hui; Hu, Xiaojie; Jin, Yunbo; Qiu, Yajing

2014-01-01

140

Aversive reactions of turkeys to argon, carbon dioxide and a mixture of carbon dioxide and argon.  

PubMed

The reactions of turkeys to the presence of either 90 per cent argon in air (anoxia), 72 per cent carbon dioxide in air or a mixture of 30 per cent carbon dioxide and 60 per cent argon in air with 3 per cent residual oxygen were tested. The majority of the turkeys did not avoid a feeding chamber containing either argon or the mixture of carbon dioxide and argon, but 50 per cent of the turkeys avoided a feeding chamber containing 72 per cent carbon dioxide in air. It is concluded that from the point of view of welfare, either 90 per cent argon in air or a mixture of 30 per cent carbon dioxide and 60 per cent argon in air, would be preferable to a high concentration of carbon dioxide for stunning/killing turkeys. PMID:8799986

Raj, A B

1996-06-15

141

Photolytical Generation of Carbon Dioxide  

NASA Astrophysics Data System (ADS)

Carbon dioxide has been found by Cassini VIMS throughout the Saturnian system in locations such as Iapetus' equator where the temperature is too high for it to remain as free ice for more than a few hundred years. We suggest that the 4.26 micron absorption feature found on Iapetus and Hyperion (that has been attributed to complexed CO2) is the result of either UV photolysis or ion bombardment driving chemistry between the carbon rich layer and the water ice regolith. We conducted experiments to simulate the generation of CO2 by UV radiation under conditions similar to those on the surface of Iapetus. A simulated icy regolith was created in an argon atmosphere using flash-frozen, degassed water crushed into sub-millimeter sized particles. Isotopically labeled amorphous carbon (13C), which was ground into a fine dust, was mixed into the regolith allowing for extensive grain contact. This sample was placed in a vacuum chamber and cooled to temperatures as low at 60K. The sample was irradiated with UV light, and the products were measured using both a mass spectrometer to identify free molecules and an IR spectrometer for molecules that remained trapped on and in the simulated regolith. We report on the production and reaction rates of CO2 and CO, as well as the generation of free hydrogen and oxygen as detected by a SRS-100 mass spectrometer. We also identify residual products that either freeze on the surface or become entrained by or adsorbed onto the ice grains. We attempt to match the CO2 absorption feature found on Iapetus with that seen in our simulation, perhaps identifying a possible source of CO2 in the Saturnian system. Finally, we estimate the time required for these reactions to occur on Iapetus to see if UV photolysis would be effective.

Palmer, E. E.; Brown, R. H.

2008-12-01

142

Carbon dioxide conversion over carbon-based nanocatalysts.  

PubMed

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

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

2013-07-01

143

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...

144

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.

1994-01-01

145

Bench-to-bedside review: Carbon dioxide  

Microsoft Academic Search

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\\u000a underappreciated - component of many disease states, including early asthma, high-altitude pulmonary edema, and acute lung\\u000a injury. Induction of hypocapnia remains a common, if controversial, practice

Gerard Curley; John G Laffey; Brian P Kavanagh

2010-01-01

146

Treatment of Acne Scars and Wrinkles in Asian Patients Using Carbon-Dioxide Fractional Laser Resurfacing: Its Effects on Skin Biophysical Profiles  

PubMed Central

Background Although ablative fractional resurfacing is known to be effective against photoaging and acne scars, studies on its efficacy, safety and changes in the skin characteristics of Asians are limited. Objective The aim of this study is to assess the efficacy and safety of carbon dioxide fractional laser (CO2FL) in Koreans treated for wrinkles and acne scars, and to define the changes in skin characteristics during recovery period. Methods We administered one session of CO2FL on 10 acne scar patients and 14 wrinkles patients with skin types IV and V. The surveillance of efficacy and side effects along with the measurement of biophysical properties was carried out before 1 day, 1 week, 1 month and 3 months after treatment. Results Using a non-invasive method, skin barrier damage, erythema and bronzing of skin during the recovery period were assessed, and all of the items eventually returned to the pre-treatment level. Skin elasticity was measured in the wrinkle group, and the statistically significant effect was sustained throughout the next three months. The outcome of treatment was found to be better than 'moderate improvement' in both the acne scar and wrinkle groups. Further, there were no serious side effects three months post-procedure. Conclusion CO2 FL is thought to be an effective and safe method for treating moderate to severe acne scars and wrinkles in Asians. PMID:24371392

Hwang, Young Ji; Lee, Yu Na; Choe, Yong Beom; Ahn, Kyu Joong

2013-01-01

147

Highly sensitive absorption spectroscopy of carbon dioxide by ICLAS-VeCSEL between 8800 and 9530 cm ?1  

Microsoft Academic Search

The absorption spectrum of carbon dioxide has been studied between 8800 and 9530cm?1 by intracavity laser absorption spectroscopy based on a vertical external cavity surface emitting lasers (VeCSEL). Previous laboratory spectra at high resolution were nearly absent in the considered spectral region. Experiments were carried with natural carbon dioxide and with 13C enriched carbon dioxide leading to the determination of

Y. Ding; A. Campargue; E. Bertseva; S. Tashkun; V. I. Perevalov

2005-01-01

148

Development and Metrological Characterization of a Tunable Diode Laser Absorption Spectroscopy (TDLAS) Spectrometer for Simultaneous Absolute Measurement of Carbon Dioxide and Water Vapor.  

PubMed

Simultaneous detection of two analytes, carbon dioxide (CO2) and water vapor (H2O), has been realized using tunable diode laser absorption spectroscopy (TDLAS) with a single distributed feedback diode laser at 2.7 ?m. The dynamic range of the spectrometer is extended from the low parts per million to the percentage range using two gas cells, a single-pass cell with 0.77 m, and a Herriott-type multipass cell with 76 m path length. Absolute measurements were carried out, i.e., amount fractions of the analytes were calculated based on previously determined spectral line parameters, without the need for an instrument calibration using gas standards. A thorough metrological characterization of the spectrometer is presented. We discuss traceability of all parameters used for amount fraction determination and provide a comprehensive uncertainty assessment. Relative expanded uncertainties (k = 2, 95% confidence level) of the measured amount fractions are shown to be in the 2-3% range for both analytes. Minimum detectable amount fractions are 0.16 ?mol/mol for CO2 and 1.1 ?mol/mol for H2O for 76 m path length and 5 s averaging time. This corresponds to normalized detection limits of 27 ?mol/mol m Hz(-1/2) for CO2 and 221 ?mol/mol m Hz(-1/2) for H2O. Precision of the spectrometer, determined using Allan variance analysis, is 3.3 nmol/mol for CO2 and 21 nmol/mol for H2O. The spectrometer has been validated using reference gas mixtures with known CO2 and H2O amount fractions. An application example of the absolute TDLAS spectrometer as a reference instrument to validate other sensors is also presented. PMID:25658222

Pogány, Andrea; Wagner, Steven; Werhahn, Olav; Ebert, Volker

2015-02-01

149

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

150

Therapy of deep caries by transverse excited atmosphere pressure carbon dioxide laser: an in-vitro investigation  

NASA Astrophysics Data System (ADS)

Deep carious decay is still a problem for conservative dentistry. A prototype of a transverse excited atmospheric pressure carbondioxide laser (TEA-CO2-Laser) was used for testing the properties in selective ablation of softened carious dentin, artificially sclerosing the remaining dentin, and providing thermal damage for the pulp. Using low pulse frequencies of 1 or 2 Hz, pulse durations of 50 ns, and pulse energies of 5 J/cm2 the TEA-CO2- Laser seems to be able to solve the therapeutic problem.

Meese, Gabriele; Zuhrt, Rainer

1993-07-01

151

Micron-sized droplets irradiated with a pulsed carbon dioxide laser: Measurement of explosion and breakdown thresholds  

Microsoft Academic Search

We present the results of measurements of explosive vaporization and plasma breakdown thresholds of micron-sized droplets irradiated by a pulsed CO2 laser operating at 10.6 microns. Well-defined explosion and breakdown patterns are observed when the incident laser intensity exceeds the threshold value. In the infrared region, the breakdown threshold is larger than the vaporization threshold by a factor of approximately

R. L. Armstrong; A. Biswas; R. G. Pinnick; J. D. Pendleton

1995-01-01

152

Atmospheric Lifetime of Fossil Fuel Carbon Dioxide  

E-print Network

Atmospheric Lifetime of Fossil Fuel Carbon Dioxide David Archer,1 Michael Eby,2 Victor Brovkin,3 released from combustion of fossil fuels equilibrates among the various carbon reservoirs of the atmosphere literature on the atmospheric lifetime of fossil fuel CO2 and its impact on climate, and we present initial

Scherer, Norbert F.

153

Carbon dioxide laser-assisted nerve repair: effect of solder and suture material on nerve regeneration in rat sciatic nerve.  

PubMed

In order to further improve and explore the role of lasers for nerve reconstruction, this study was designed to investigate regeneration of sharply transected peripheral nerves repaired with a CO(2) milliwatt laser in combination with three different suture materials and a bovine albumin protein solder as an adjunct to the welding process. Unilateral sciatic nerve repair was performed in 44 rats. In the laser group, nerves were gently apposed, and two stay sutures (10-0 nylon, 10-0 polyglycolic acid, or 25 microm stainless steel) were placed epi/perineurially. Thereafter, the repair site was fused at 100 mW with pulses of 1.0 s. In the subgroup of laser-assisted nerve repair (LANR), albumen was used as a soldering agent to further reinforce the repair site. The control group consisted of nerves repaired by conventional microsurgical suture repair (CMSR), using 4-6 10-0 nylon sutures. Evaluation was performed at 1 and 6 weeks after surgery, and included qualitative and semiquantitative light microscopy. LANR performed with a protein solder results in a good early peripheral nerve regeneration, with an optimal alignment of nerve fibers and minimal connective tissue proliferation at the repair site. All three suture materials produced a foreign body reaction; the least severe was with polyglycolic acid sutures. CMSR resulted in more pronounced foreign-body granulomas at the repair site, with more connective-tissue proliferation and axonal misalignment. Furthermore, axonal regeneration in the distal nerve segment was better in the laser groups. Based on these results, CO(2) laser-assisted nerve repair with soldering in combination with absorbable sutures has the potential of allowing healing to occur with the least foreign-body reaction at the repair site. Further experiments using this combination are in progress. PMID:12740882

Menovsky, Tomas; Beek, Johan F

2003-01-01

154

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.

155

Method for Extracting and Sequestering Carbon Dioxide  

SciTech Connect

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

Rau, Gregory H.; Caldeira, Kenneth G.

2005-05-10

156

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

157

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

158

[An autopsy case of carbon dioxide intoxication].  

PubMed

A 44-year-old male, engaged in the transportation of dry ice, was found dead on the floor of the freezer of his refrigerator car which was parked in front of the place where he was scheduled to make a delivery. Autopsy was performed to investigate the cause of death. Apart from the signs of acute death, no other significant findings were obtained, either macro or microscopically; carbon dioxide poisoning was thus strongly suspected. We created a simulation experiment by using the refrigerator car to reproduce the events of the accident. The oxygen concentration in the freezer was 21.0% as indicated by oxygen sensors, but decreased to 17.1-17.4% when the engine was stopped. This decrease in oxygen concentration supposedly results from the production of carbon dioxide by the vaporization of dry ice. Carbon dioxide concentration in the air could be calculated from the change in the oxygen concentration in the closed space of the freezer. The concentration was assessed at 17.1-18.6%. An oxygen concentration of 17.1-17.4% does not of itself cause serious hypoxia, but a carbon dioxide concentration of 17.1-18.6% probably causes serious intoxication, because this value is beyond that of intoxication levels published in references. Therefore, we concluded that the cause of death in this case was carbon dioxide intoxication. PMID:9545760

Yamazaki, M; Islam, M N; Ogura, Y; Honda, K; Tsuchihashi, H; Nishioka, H

1997-12-01

159

Designed amyloid fibers as materials for selective carbon dioxide capture  

PubMed Central

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

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

2014-01-01

160

Therapeutic benefits of carbon dioxide (CO2) laser on single-site HPV lesions in the lower female genital tract  

NASA Astrophysics Data System (ADS)

Numerous studies have shown contradictory variable percentages of recurrent HPV lesions, after various therapies. The present study therefore evaluates the effectiveness of CO2 laser vaporization in the treatment of single-site HPV lesions of the lower female genital tract in order to confirm the conviction that physical therapy alone, in agreement with some findings reported in the literature, is capable of guaranteeing a high cure rate in selected patients. From January 1995 to June 1996, seventy- five female patients were treated with CO2 laser vaporization for single-site genital HPV lesions, some of which were associated with low-grade intra-epithelial neoplasia. The success rate after 12 months proved to be 97%. The pre-existing clinical symptoms disappeared in all the patients treated. No complication in the vaporization procedure was encountered.

Urru, Giovanni; Moretti, Gianfranco

1998-01-01

161

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

162

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

163

Performance of an exhaled nitric oxide and carbon dioxide sensor using quantum cascade laser-based integrated cavity output spectroscopy  

Microsoft Academic Search

Exhaled nitric oxide NO is an important biomarker in asthma and other respiratory disorders. The optical performance of a NO\\/CO2 sensor employing integrated cavity output spectroscopy ICOS with a quantum cascade laser operating at 5.22 m capable of real-time NO and CO2 measurements in a single breath cycle is reported. A NO noise-equivalent concentration of 0.4 ppb within a 1-sec

Matthew R. McCurdy; Yury Bakhirkin; Gerard Wysocki; Frank K. Tittel

2007-01-01

164

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

165

Polymers for metal extractions in carbon dioxide  

DOEpatents

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

DeSimone, Joseph M. (7315 Crescent Ridge Dr., Chapel Hill, NC 27516); Tumas, William (1130 Big Rock Loop, Los Alamos, NM 87544); Powell, Kimberly R. (103 Timber Hollow Ct. Apartment 323, Chapel Hill, NC 27514); McCleskey, T. Mark (1930 Camino Mora, Los Alamos, NM 87544); Romack, Timothy J. (5810 Forest Ridge Dr., Durham, NC 27713); McClain, James B. (8530 Sommersweet La., Raleigh, NC 27612); Birnbaum, Eva R. (1930 Camino Mora, Los Alamos, NM 87544)

2001-01-01

166

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 tanks—one tank with Elodea and one without—is 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.

American Educational Products

1992-01-01

167

Progress in Measurement of Carbon Dioxide Using a Broadband Lidar  

NASA Technical Reports Server (NTRS)

In order to better understand the budget of carbon dioxide in the Earth's atmosphere it is necessary to develop a global high precision understanding of the carbon dioxide column. In order to uncover the 'missing sink" that is responsible for the large discrepancies in the budget as we presently understand it calculation has indicated that measurement accuracy on the order of 1 ppm is necessary. Because typical column average CO2 has now reached 380 ppm this represents a precision on the order of .25% for these column measurements. No species has ever been measured from space at such a precision. In recognition of the importance of understanding the CO2 budget in order to evaluate its impact on global warming the National Research Council in its decadal survey report to NASA recommended planning for a laser based total CO2 mapping mission in the near future. The extreme measurement accuracy requirements on this mission places very strong requirements on the laser system used for the measurement. This work presents an overview of the characteristics necessary in a laser system used to make this measurement. Consideration is given to the temperature dependence, pressure broadening, and pressure shift of the CO2 lines themselves and how these impact the laser system characteristics We have been examining the possibility of making precise measurements of atmospheric carbon dioxide using broad band source of radiation. This means that many of the difficulties in wavelength control can be treated in the detector portion of the system rather than the laser source. It also greatly reduces the number of individual lasers required to make a measurement. Simplifications such as these are extremely desirable for systems designed to operate from space.

Heaps, William S.

2010-01-01

168

Carbon Dioxide Information Analysis Center (CDIAC)  

NSDL National Science Digital Library

Based at Oak Ridge National Laboratories in Tennessee, this Website is the US Department of Energy's "primary global-change data and information analysis center" and is a central source for many Carbon Dioxide-related resources. Among those resources are several we have reviewed, for example, the Catalog of Databases and Reports (reviewed in the June 24, 1998 Scout Report for Science & Engineering) and Carbon Dioxide Emission Estimates (reviewed in the March 4, 1998 Scout Report for Science & Engineering). The CDIAC site offers a wealth of information, including "records of the concentrations of carbon dioxide and other radiatively active gases in the atmosphere; the role of the terrestrial biosphere and the oceans in the biogeochemical cycles of greenhouse gases; emissions of carbon dioxide to the atmosphere; long-term climate trends; the effects of elevated carbon dioxide on vegetation; and the vulnerability of coastal areas to rising sea level." To get a feel for the research summaries and data available at the CDIAC site, see the Products section (describes the research projects associated with CDIAC as well as links to those data sets); the New section (offers a hyperlinked list of new data products); the Top 10 section (offers a hyperlinked list of Frequently Requested Global Change Products); or any of the specific project sections: FACE (Free Air CO2 Enrichment), NARSTO (a non-binding, tri-national, public/private alliance), OCEANS (Survey of CO2 in the Oceans), or AmeriFlux (long-term CO2 flux measurements of the Americas). This is an outstanding resource for those seeking global data (or research summaries) on the status of carbon dioxide in several components of the earth's ecosystems.

169

Micron-sized droplets irradiated with a pulsed carbon dioxide laser: Measurement of explosion and breakdown thresholds  

NASA Astrophysics Data System (ADS)

We present the results of measurements of explosive vaporization and plasma breakdown thresholds of micron-sized droplets irradiated by a pulsed CO2 laser operating at 10.6 microns. Well-defined explosion and breakdown patterns are observed when the incident laser intensity exceeds the threshold value. In the infrared region, the breakdown threshold is larger than the vaporization threshold by a factor of approximately 10(exp 2). Although, to the authors knowledge, no analogous measurements of vaporization and breakdown thresholds of individual aerosol particles exist in the microwave region, scaling of our infrared measurements to deduce the corresponding microwave properties is possible using available theoretical models. When this scaling is performed, it suggests that a dramatic reversal of explosion and breakdown thresholds occurs in the microwave region. In this region, the microwave vaporization threshold is larger than the corresponding breakdown threshold by a factor of greater than 10(exp 4). Recent measurements of breakdown thresholds in aerosol-laden air provide indirect evidence that this reversal has, in fact, taken place.

Armstrong, R. L.; Biswas, A.; Pinnick, R. G.; Pendleton, J. D.

1995-03-01

170

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

171

International Space Station Carbon Dioxide Removal Assembly Testing  

NASA Technical Reports Server (NTRS)

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

Knox, James C.

2000-01-01

172

Organic syntheses employing supercritical carbon dioxide as a reaction solvent  

NASA Technical Reports Server (NTRS)

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

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

1991-01-01

173

Rapid vibrational and rotational energy-transfer rates in heated carbon dioxide collisions by double-resonance laser spectroscopy  

SciTech Connect

Rates for resonant vibrational and rotational energy transfer from the 001 state by CO/sub 2/ + CO/sub 2/ collisions have been measured. All data were obtained by double resonance spectroscopy with CO/sub 2/ lasers in a 2.5 meter absorption cell at 700/sup 0/K. Results for rotation transfer include pumped-level relaxation and the response of other 001 levels with ..delta..J up to 18. These data are compared to four relevant collision models via a 35-level rate equation analysis. Sequence-band (002 ..-->.. 101) and hot-band (011 ..-->.. 110) lasting have been used to observe resonant nu/sub 3/-transfer relaxation involving 001 + 001 reversible 002 + 000, 001 + 100 reversible 101 + 000, and 001 + 010 reversible 011 + 000. A multilevel rate analysis has been utilized to determine the rate coefficients for 001 going to the 002, the 101, and the 011 levels. Part of the hot-band data has been interpreted as due to 110 + 000 reversible 100 + 010, and the associated rate constant has been estimated. The results of the study are compared to the theory and to other experiments.

Thomason, M.D.

1982-07-01

174

U.S. Energy-Related Carbon Dioxide Emissions  

EIA Publications

U.S. Energy Information Administration releases its online analysis of 2012 energy-related carbon dioxide emissions today. It indicates U.S. carbon dioxide emissions from the consumption of fossil fuels were 5,290 million metric tons carbon dioxide in 2012, a decrease of almost 4% from the 2011 level. Energy-related carbon dioxide emissions have declined in five of the last seven years and are the lowest they have been since 1994.

2014-01-01

175

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

176

40 CFR 86.124-78 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration...Light-Duty Trucks and New Otto-Cycle Complete Heavy-Duty Vehicles...Procedures § 86.124-78 Carbon dioxide analyzer calibration...monthly thereafter the NDIR carbon dioxide analyzer shall be...

2013-07-01

177

40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration...Emission Regulations for New Otto-Cycle and Diesel Heavy-Duty Engines...Procedures § 86.1324-84 Carbon dioxide analyzer calibration...monthly thereafter, the NDIR carbon dioxide analyzer shall be...

2010-07-01

178

40 CFR 86.124-78 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration...Light-Duty Trucks and New Otto-Cycle Complete Heavy-Duty Vehicles...Procedures § 86.124-78 Carbon dioxide analyzer calibration...monthly thereafter the NDIR carbon dioxide analyzer shall be...

2010-07-01

179

40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration...Emission Regulations for New Otto-Cycle and Diesel Heavy-Duty Engines...Procedures § 86.1324-84 Carbon dioxide analyzer calibration...monthly thereafter, the NDIR carbon dioxide analyzer shall be...

2013-07-01

180

40 CFR 86.124-78 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration...Light-Duty Trucks and New Otto-Cycle Complete Heavy-Duty Vehicles...Procedures § 86.124-78 Carbon dioxide analyzer calibration...monthly thereafter the NDIR carbon dioxide analyzer shall be...

2012-07-01

181

40 CFR 86.124-78 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Carbon dioxide analyzer calibration...Light-Duty Trucks and New Otto-Cycle Complete Heavy-Duty Vehicles...Procedures § 86.124-78 Carbon dioxide analyzer calibration...monthly thereafter the NDIR carbon dioxide analyzer shall be...

2014-07-01

182

40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration...Emission Regulations for New Otto-Cycle and Diesel Heavy-Duty Engines...Procedures § 86.1324-84 Carbon dioxide analyzer calibration...monthly thereafter, the NDIR carbon dioxide analyzer shall be...

2011-07-01

183

40 CFR 86.124-78 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration...Light-Duty Trucks and New Otto-Cycle Complete Heavy-Duty Vehicles...Procedures § 86.124-78 Carbon dioxide analyzer calibration...monthly thereafter the NDIR carbon dioxide analyzer shall be...

2011-07-01

184

40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration...Emission Regulations for New Otto-Cycle and Diesel Heavy-Duty Engines...Procedures § 86.1324-84 Carbon dioxide analyzer calibration...monthly thereafter, the NDIR carbon dioxide analyzer shall be...

2012-07-01

185

Chukwuemeka I. Okoye Carbon Dioxide Solubility and Absorption Rate in  

E-print Network

Copyright by Chukwuemeka I. Okoye 2005 #12;Carbon Dioxide Solubility and Absorption Rate _______________________ Nicholas A. Peppas #12;Carbon Dioxide Solubility and Absorption Rate in Monoethanolamine/Piperazine/H2O for. #12;iii Carbon Dioxide Solubility and Absorption Rate in Monoethanolamine/Piperazine/H2O

Rochelle, Gary T.

186

Designed amyloid fibers as materials for selective carbon dioxide capture  

E-print Network

Designed amyloid fibers as materials for selective carbon dioxide capture Dan Lia,b,c,1 , Hiroyasu demonstrate that amyloids, self-assembling protein fibers, are effective for selective carbon dioxide capture. Solid-state NMR proves that amyloid fibers containing alkylamine groups reversibly bind carbon dioxide

187

A Simple Model for Atmospheric Carbon Dioxide  

NSDL National Science Digital Library

In this problem set, learners will create and use a differential equation of rate-of-change of atmospheric carbon dioxide. They will refer to the "Keeling Curve" graph and information on the sources and sinks of carbon on Earth to create the equation and apply it to answer a series of questions. Answer key is provided. This is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

2012-08-03

188

RISING CARBON DIOXIDE AND WEED ECOLOGY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Documented and projected changes in the concentration of atmospheric carbon dioxide [CO2] and other gases suggest potential changes in climate stability which could negatively impact human systems. One such system would involve negative impacts on agricultural crops and associated weeds. Climatic o...

189

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

190

21 CFR 582.1240 - Carbon dioxide.  

Code of Federal Regulations, 2010 CFR

21 ? Food and Drugs ? 6 ? 2010-04-01 ? 2010-04-01 ? false ? Carbon dioxide. ? 582.1240 ? Section 582.1240 ? Food and Drugs ? FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ? ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ? SUBSTANCES GENERALLY RECOGNIZED AS SAFE...

2010-04-01

191

21 CFR 582.1240 - Carbon dioxide.  

Code of Federal Regulations, 2012 CFR

21 ? Food and Drugs ? 6 ? 2012-04-01 ? 2012-04-01 ? false ? Carbon dioxide. ? 582.1240 ? Section 582.1240 ? Food and Drugs ? FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ? ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ? SUBSTANCES GENERALLY RECOGNIZED AS SAFE...

2012-04-01

192

21 CFR 582.1240 - Carbon dioxide.  

Code of Federal Regulations, 2011 CFR

21 ? Food and Drugs ? 6 ? 2011-04-01 ? 2011-04-01 ? false ? Carbon dioxide. ? 582.1240 ? Section 582.1240 ? Food and Drugs ? FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ? ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ? SUBSTANCES GENERALLY RECOGNIZED AS SAFE...

2011-04-01

193

21 CFR 582.1240 - Carbon dioxide.  

Code of Federal Regulations, 2014 CFR

21 ? Food and Drugs ? 6 ? 2014-04-01 ? 2014-04-01 ? false ? Carbon dioxide. ? 582.1240 ? Section 582.1240 ? Food and Drugs ? FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ? ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ? SUBSTANCES GENERALLY RECOGNIZED AS SAFE...

2014-04-01

194

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.

195

Carbon Dioxide Corrosion: Modelling and Experimental Work  

E-print Network

Carbon Dioxide Corrosion: Modelling and Experimental Work Applied to Natural Gas Pipelines Philip in the corrosion related research institutions at IFE and the Ohio University or any other scientific research;#12;Introduction - v - Summary CO2 corrosion is a general problem in the industry and it is expensive. The focus

196

CDIAC: Carbon Dioxide Information Analysis Center  

NSDL National Science Digital Library

This site is the homepage of the Carbon Dioxide Information Analysis Center (CDIAC) which includes the World Data Center for Atmospheric Trace Gases. CDIAC is the primary global-change data and information analysis center of the U.S. Department of Energy (DOE). CDIAC responds to data and information requests from users from all over the world who are concerned with the greenhouse effect and global climate change. CDIAC's data holdings include records of the concentrations of carbon dioxide and other radiatively active gases in the atmosphere; the role of the terrestrial biosphere and the oceans in the biogeochemical cycles of greenhouse gases; emissions of carbon dioxide to the atmosphere; long-term climate trends; the effects of elevated carbon dioxide on vegetation; and the vulnerability of coastal areas to rising sea level. In operation since 1982, CDIAC: obtains, evaluates, and archives data, compiles and distributes digital numeric data packages and computer model packages, provides data management support to global-change related scientific projects, distributes related reports, produces the newsletter, CDIAC Communications, and in general acts as the information focus for the U.S. DOE Global Change Research Program. CDIAC is supported by DOE's Environmental Sciences Division of the Office of Biological and Environmental Research. CDIAC represents DOE in the multi-agency Global Change Data and Information System.

197

Atmospheric carbon dioxide record from Mauna Loa  

NSDL National Science Digital Library

The Scripps Institute of Oceanography has released these data consisting of monthly carbon dioxide concentrations at Mauna Loa 1958-1999. Measurements were made using a nondispersive infrared gas analyzer with a water vapor freeze trap. The data are available as graphs or tables. The text includes a brief overview of the methods and a reference list.

198

The Transport Properties of Carbon Dioxide  

Microsoft Academic Search

The paper contains new, representative equations for the viscosity and thermal conductivity of carbon dioxide. The equations are based in part upon a body of experimental data that have been critically assessed for internal consistency and for agreement with theory whenever possible. In the case of the low-density thermal conductivity at high temperatures, all available data are shown to be

V. Vesovic; W. A. Wakeham; G. A. Olchowy; J. V. Sengers; J. T. R. Watson; J. Millat

1990-01-01

199

Recent Events: a Perspective on Carbon Dioxide  

NSDL National Science Digital Library

In this problem set, learners will compare the carbon dioxide produced as a result of two 2010 events: the eruption of the Eyjafjalla Volcano and the burning of oil on the ocean surface to address the Gulf of Mexico oil spill. Answer key is provided. This is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

200

Inhalation of Carbon Dioxide at High Altitudes  

Microsoft Academic Search

THE suggestion put forward in NATURE of March 23 (p. 457) by Prof. Yandell Henderson and others to the effect that carbon dioxide might be of use in high altitude climbing reminds me of some trials carried out about ten years ago. Messrs. Siebe German and Co., Ltd., had similar ideas, and they lent me a rebreathing mask to try

P. J. H. Unna

1935-01-01

201

Carbon Dioxide Production at Home  

NSDL National Science Digital Library

In this problem set, learners will consider the "Carbon Footprint" of a family of four in a given context, as well as the US and global averages, and compare that with their own to answer a series of questions. They will use an online Carbon Footprint calculator to determine their own per-capita carbon production. Answer key is provided. This problem is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

2012-08-03

202

Dynamic solubility measurements of caffeine in carbon dioxide and in carbon dioxide saturated with water  

NASA Astrophysics Data System (ADS)

The solubility of caffeine in dry carbon dioxide has been measured between 310 and 430 K up to 70 MPa. The solubility of caffeine in carbon dioxide saturated with water has been measured between 303 and 363 K up to 30 MPa. The results can be reproduced by simple equations. These equations allow a calculation of the solubilities at higher and lower pressures. Using these equations, cross virial coefficients have been calculated for both systems.

Lentz, Harro; Gehrig, Manfred; Schulmeyer, Josef

1986-05-01

203

Carbon Dioxide Snow Storms During the Polar Night on Mars  

NASA Technical Reports Server (NTRS)

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

Toon, Owen B.; Colaprete, Anthony

2001-01-01

204

Morphological Changes of Human Dentin after Erbium-Doped Yttrium Aluminum Garnet (Er:YAG) and Carbon Dioxide (CO2) Laser Irradiation and Acid-etch Technique: An Scanning Electron Microscopic (SEM) Evaluation  

PubMed Central

Introduction: The aim of this study was to investigate the morphological changes of human dentin after Erbium-Doped Yttrium Aluminum Garnet (Er:YAG), Carbon Dioxide(CO2) laser-irradiation and acid-etching by means of scanning electron microscopic (SEM) Methods: 9 extracted human third molars were used in this study. The teeth were divided in three groups: first group, CO2 laser with power of 1.5 w and frequency of 80 Hz; second group, Er:YAG laser with output power of 1.5 W frequency of 10 Hz, very short pulse with water and air spray was applied; and third group, samples were prepared by acid-etching 37% for 15 sec and rinsed with air-water spray for 20 sec. Then, the samples were prepared for SEM examination. Results: Melting and cracks can be observed in CO2 laser but in Er:YAG laser cleanedablated surfaces and exposed dentinal tubules, without smear layer was seen. Conclusion: It can be concluded that Er:YAG laser can be an alternative technique for surface treatment and can be considered as safe as the conventional methods. But CO2 laser has some thermal side effects which make this device unsuitable for this purpose. PMID:25606306

Shahabi, Sima; Chiniforush, Nasim; Juybanpoor, Nasrin

2013-01-01

205

Coral, Carbon Dioxide and Calcification  

NSDL National Science Digital Library

In this group activity, learners act out key stages of the "ocean carbon cycle" (also known as the "carbonate buffer system") through motions, rearranging blocks and team tasks. Learners will also hypothesize the potential effects on the ocean and coral when variables are changed (e.g. the addition of massive amounts of CO2 and increased water temperature). At least 8 learners are needed to participate in the simulation. This detailed lesson plan includes an introduction, background information related to corals and the ocean carbon cycle, and adaptation suggestions for younger learners.

Stephanie L. Anderson

2012-07-17

206

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

207

Transport of Carbon Dioxide and Radioactive Waste  

Microsoft Academic Search

\\u000a A comparative assessment of carbon dioxide (CO2) and radioactive waste transport systems associated with electricity generation was undertaken on the basis of 15 criteria\\u000a grouped under three areas, namely the transport chain, policy aspects and state of the technology. For CO2, we considered exclusively the transport that would take place under a future large-scale capture and storage infrastructure.\\u000a Our study

Darío R. Gómez; Michael Tyacke

208

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

209

Electrochemical carbon dioxide concentrator: Math model  

NASA Technical Reports Server (NTRS)

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

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

1973-01-01

210

LASER SPECTROSCOPY: Measurement of the concentration ratio for 13Ñ and 12Ñ isotopes at atmospheric pressure by carbon dioxide absorption of diode laser radiation at ~2 ?m  

NASA Astrophysics Data System (ADS)

The ratio of 12ÑO2 and 13CO2 concentrations in the human exhaled air is measured by the method of diode laser spectroscopy using a three-channel optical scheme and multipass cell. Unlike the previous measurements in the spectral range of ~4.3 ?m with a resolved rotational structure at low pressure of selected samples, the present measurements are performed in the range of ~2 ?m, in which weaker absorption bands of CO2 reside. In this case, it is possible to employ lasers and photodetectors operating at room temperature. The thorough simulation of the spectrum with collisional broadening of lines and employment of regression analysis allow one to take measurements at atmospheric pressure with the accuracy of ~0.04%, which satisfies the requirements to medical diagnostics of ulcers.

Mironchuk, E. S.; Nikolaev, I. V.; Ochkin, Vladimir N.; Rodionova, S. S.; Spiridonov, Maksim V.; Tskhai, Sergei N.

2009-04-01

211

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

212

Nonlinear carbon dioxide at high pressures and temperatures.  

PubMed

A nonlinear molecular carbon dioxide phase IV was discovered by laser heating CO2-III (Cmca) between 12 and 30 GPa, followed by quenching to 300 K. The Raman spectrum of quenched CO2-IV exhibits a triplet bending mode nu2(O = C = O) near 650 cm (-1), suggesting a broken inversion symmetry because of bending. The 650 cm (-1) bending modes soften with increasing pressure, indicating an enhanced intermolecular interaction among neighboring bent CO2 molecules. At 80 GPa, the low-frequency vibron collapses into high-frequency phonons, and CO2-IV becomes an extended amorphous solid. PMID:11177851

Yoo, C S; Iota, V; Cynn, H

2001-01-15

213

Carbon dioxide reduction by the Bosch process  

NASA Technical Reports Server (NTRS)

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

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

1975-01-01

214

Carbon Dioxide Aquariums Greenhouse Gas Lesson  

NSDL National Science Digital Library

This classroom activity looks at carbon dioxide and its role in climate change. Students will perform an in-class experiment using aquariums. CO2 gas will be added to one aquarium, and measurements are taken of both aquariums over a one or two week period. This lesson includes step by step instructions on carrying out the experiment. The unit is a good introduction to the concepts of the carbon cycle, heat transfer, energy flow in ecosystems, the human impact on ecosystems and climate, non-renewable energy, resource consumption and pollution. This document may be downloaded in PDF file format. A class worksheet is included with the document.

Orzali, Joe

2009-01-01

215

Carbon dioxide sensitivity of zeolitic imidazolate frameworks.  

PubMed

Zeolitic imidazolate frameworks of zinc, cobalt, and cadmium, including the framework ZIF-8 commercially sold as Basolite Z1200, exhibit surprising sensitivity to carbon dioxide under mild conditions. The frameworks chemically react with CO2 in the presence of moisture or liquid water to form carbonates. This effect, which has been previously not reported in metal-organic framework chemistry, provides an explanation for conflicting reports on ZIF-8 stability to water and is of outstanding significance for evaluating the potential applications of metal-organic frameworks, especially for CO2 sequestration. PMID:24889776

Mottillo, Cristina; Friš?i?, Tomislav

2014-07-14

216

Elevated atmospheric carbon dioxide increases soil carbon  

SciTech Connect

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

Norby, Richard J [ORNL; Jastrow, Julie D [ORNL; Miller, Michael R [ORNL; Matamala, Roser [Argonne National Laboratory (ANL); Boutton, Thomas W [Texas A& M University; Rice, Charles W [ORNL; Owensby, Clenton E [Kansas State University

2005-01-01

217

Atmospheric Carbon Dioxide and Carbon Reservoir Changes  

Microsoft Academic Search

The net release of CO2 from the biosphere to the atmosphere between 1850 and 1950 is estimated to amount to 1.2 × 109 tons of carbon per year. During this interval, changes in land use reduced the total terrestrial biomass by 7 percent. There has been a smaller reduction in biomass over the last few decades. In the middle 19th

Minze Stuiver

1978-01-01

218

Carbon dioxide disposal in carbonate minerals  

Microsoft Academic Search

We introduce a safe and permanent method of CO2 disposal based on combining CO2 chemically with abundant raw materials to form stable carbonate minerals. Substantial heat is liberated in the overall chemical reaction so that cost will be determined by the simplicity and speed of the reaction rather than the cost of energy. Preliminary investigations have been conducted on two

Klaus S. Lackner; Christopher H. Wendt; Darryl P. Butt; Edward L. Joyce; David H. Sharp

1995-01-01

219

Elevated atmospheric carbon dioxide increases soil carbon  

Microsoft Academic Search

In a study funded by the U.S. Department of Energy's Office of Science, researchers from Argonne and Oak Ridge National Laboratories and Kansas State and Texas A&M Universities evaluated the collective results of earlier studies by using a statistical procedure called meta-analysis. They found that on average elevated CO2 increased soil carbon by 5.6 percent over a two to nine

Richard J Norby; Michael R Miller; Roser Matamala; THOMAS W. BOUTTON; CHARLES W. RICE; CLENTON E. OWENSBY

2005-01-01

220

Automated carbon dioxide cleaning system  

NASA Technical Reports Server (NTRS)

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

Hoppe, David T.

1991-01-01

221

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

222

Carbon Dioxide Transport through Membranes*  

PubMed Central

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

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

2008-01-01

223

Robust carbon dioxide reduction on molybdenum disulphide edges.  

PubMed

Electrochemical reduction of carbon dioxide has been recognized as an efficient way to convert carbon dioxide to energy-rich products. Noble metals (for example, gold and silver) have been demonstrated to reduce carbon dioxide at moderate rates and low overpotentials. Nevertheless, the development of inexpensive systems with an efficient carbon dioxide reduction capability remains a challenge. Here we identify molybdenum disulphide as a promising cost-effective substitute for noble metal catalysts. We uncover that molybdenum disulphide shows superior carbon dioxide reduction performance compared with the noble metals with a high current density and low overpotential (54?mV) in an ionic liquid. Scanning transmission electron microscopy analysis and first principle modelling reveal that the molybdenum-terminated edges of molybdenum disulphide are mainly responsible for its catalytic performance due to their metallic character and a high d-electron density. This is further experimentally supported by the carbon dioxide reduction performance of vertically aligned molybdenum disulphide. PMID:25073814

Asadi, Mohammad; Kumar, Bijandra; Behranginia, Amirhossein; Rosen, Brian A; Baskin, Artem; Repnin, Nikita; Pisasale, Davide; Phillips, Patrick; Zhu, Wei; Haasch, Richard; Klie, Robert F; Král, Petr; Abiade, Jeremiah; Salehi-Khojin, Amin

2014-01-01

224

Effects of carbon dioxide on Penicillium chrysogenum: an autoradiographic study  

SciTech Connect

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

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

1988-06-20

225

Robust carbon dioxide reduction on molybdenum disulphide edges  

NASA Astrophysics Data System (ADS)

Electrochemical reduction of carbon dioxide has been recognized as an efficient way to convert carbon dioxide to energy-rich products. Noble metals (for example, gold and silver) have been demonstrated to reduce carbon dioxide at moderate rates and low overpotentials. Nevertheless, the development of inexpensive systems with an efficient carbon dioxide reduction capability remains a challenge. Here we identify molybdenum disulphide as a promising cost-effective substitute for noble metal catalysts. We uncover that molybdenum disulphide shows superior carbon dioxide reduction performance compared with the noble metals with a high current density and low overpotential (54?mV) in an ionic liquid. Scanning transmission electron microscopy analysis and first principle modelling reveal that the molybdenum-terminated edges of molybdenum disulphide are mainly responsible for its catalytic performance due to their metallic character and a high d-electron density. This is further experimentally supported by the carbon dioxide reduction performance of vertically aligned molybdenum disulphide.

Asadi, Mohammad; Kumar, Bijandra; Behranginia, Amirhossein; Rosen, Brian A.; Baskin, Artem; Repnin, Nikita; Pisasale, Davide; Phillips, Patrick; Zhu, Wei; Haasch, Richard; Klie, Robert F.; Král, Petr; Abiade, Jeremiah; Salehi-Khojin, Amin

2014-07-01

226

Enriching blast furnace gas by removing carbon dioxide.  

PubMed

Blast furnace gas (BF gas) produced in the iron making process is an essential energy resource for a steel making work. As compared with coke oven gas, the caloric value of BF gas is too low to be used alone as fuel in hot stove because of its high concentrations of carbon dioxide and nitrogen. If the carbon dioxide in BF gas could be captured efficiently, it would meet the increasing need of high caloric BF gas, and develop methods to reusing and/or recycling the separated carbon dioxide further. Focused on this, investigations were done with simple evaluation on possible methods of removing carbon dioxide from BF gas and basic experiments on carbon dioxide capture by chemical absorption. The experimental results showed that in 100 minutes, the maximum absorbed doses of carbon dioxide reached 20 g/100 g with ionic liquid as absorbent. PMID:25078829

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

2013-12-01

227

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 success…

Brewer, Carol A.; Beiswenger, Jane M.

1993-01-01

228

Carbon Dioxide Addition to Microbial Fuel Cell Cathodes Maintains  

E-print Network

Carbon Dioxide Addition to Microbial Fuel Cell Cathodes Maintains Sustainable Catholyte p losses and, therefore, power losses. Here, we report that adding carbon dioxide (CO2) gas to the cathodeH imbalances in contrast to the CO2/carbonate buffered catholyte system by Torres,Lee,andRittmann[Environ. Sci

Angenent, Lars T.

229

FRONTIERS ARTICLE On the hydration and hydrolysis of carbon dioxide  

E-print Network

FRONTIERS ARTICLE On the hydration and hydrolysis of carbon dioxide Alice H. England a,b , Andrew M August 2011 a b s t r a c t The dissolution of carbon dioxide in water and the ensuing hydrolysis, and hydration strength. Ã? 2011 Elsevier B.V. All rights reserved. 1. Introduction The hydrolysis of carbon

Cohen, Ronald C.

230

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

231

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

232

Supercritical carbon dioxide: a solvent like no other  

PubMed Central

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

Peach, Jocelyn

2014-01-01

233

Upgrading carbon dioxide by incorporation into heterocycles.  

PubMed

Carbon dioxide is commonly regarded as the primary greenhouse gas, but from a synthetic standpoint can be utilized as an alternative and sustainable C1 synthon in organic synthesis rather than a waste. This results in the production of organic carbonates, carboxylic acids, and derivatives. Recently, CO2 has emerged as an appealing tool for heterocycle synthesis under mild conditions without using stoichiometric amounts of organometallic reducing reagents. This Minireview summarizes recent advances on methodologies for CO2 incorporation into N-, O-, and C-nucleophiles to provide various heterocycles, including cyclic carbamates, benzoxazine-2-one, 4-hydroxyquinolin-2-one, quinazoline-2,4(1?H,3?H)-diones, benzimidazolones, ?-alkylidene cyclic carbonate. PMID:25209543

Yu, Bing; He, Liang-Nian

2015-01-01

234

Carbon dioxide absorbent and method of using the same  

SciTech Connect

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

Perry, Robert James; O'Brien, Michael Joseph

2014-06-10

235

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

236

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

237

Displacement of crude oil by carbon dioxide  

E-print Network

that passed through the core. Seeson and Ortloff conducted a laboratory study in which they investigated the oil recovery from displacing some high and low viscosity crudes from linear sandstone models. A 400 cp Ada crude oil was displaced from linear... Topedo sandstone and a 6 cp Loudon crude oil was displaced from linear models of Weiler sand- stone at 70 F and at about 1000 psi by water propelled carbon dioxide slugs. They found that the displacement technique was more efficient than waterflooding...

Omole, Olusegun

2012-06-07

238

Sigmoid perforation by compressed carbon dioxide.  

PubMed

Self-induced injuries of the bowel have various accidental mechanisms. This is a report of a 35-year-old patient with disruption of the recto-sigmoid junction caused by carbon dioxide (CO2) originating from a bottle of sparkling wine, which was introduced transanally for sexual stimulation. The patient underwent resection of the recto-sigmoid junction and primary anastomosis. The postoperative course was uneventful except for wound infection. The patient was discharged 12 days later. The physical backgrounds, the pathological pathways for perforation and diagnostic modalities including diagnostic pitfalls are critically discussed. PMID:15932178

Ikapischke, Matthias; Tepel, Juergen; Pai, Muhdra; Schulz, Tim

2005-03-01

239

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

240

Electrochemical carbon dioxide concentrator subsystem development  

NASA Technical Reports Server (NTRS)

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

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

1983-01-01

241

Capture of carbon dioxide by hybrid sorption  

DOEpatents

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

Srinivasachar, Srivats

2014-09-23

242

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

243

The kinetics of binding carbon dioxide in magnesium carbonate  

SciTech Connect

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

Butt, D.P.; Lackner, K.S.; Wendt, C.H.; Vaidya, R.; Pile, D.L.; Park, Y.; Holesinger, T.; Harradine, D.M. [Los Alamos National Lab., NM (United States); Nomura, Koji [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.]|[Chichibu Onada Cement Co., Tokyo (Japan)

1998-08-01

244

The lifetime of excess atmospheric carbon dioxide  

SciTech Connect

Since the beginning of the industrial revolution human activity has significantly altered biogeochemical cycling on a global scale. The uncertainties of future climate change rests partly on issues of physical-climate system dynamics and their representation in general circulation models. However understanding the carbon cycle is a key to comprehending the changing terrestrial biosphere and to developing a reasonable range of future concentrations of greenhouse gases. The authors look at correction of model uncertainties in the examination of the lifetime of carbon dioxide. The two difficulties analysed are as follows: (1) most model-derived estimates of the relaxation of the concentration of CO2 reveal a function which is not always well approximated by weighted sums of exponentials; (2) the function c(t) is quite sensitive to assumptions about the terrestrial biosphere and the relaxation experiment. 51 refs., 15 figs., 7 tabs.

Moore, B. III; Braswell, B.H. (Univ. of New Hampshire, Durham, NH (United States))

1994-03-01

245

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

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Indwelling blood carbon dioxide partial pressure (PCO2...Diagnostic Devices § 868.1150 Indwelling blood carbon dioxide partial pressure (PCO2... (a) Identification. An indwelling blood carbon dioxide partial pressure...

2010-04-01

246

46 CFR 167.45-45 - Carbon dioxide fire extinguishing system requirements.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Carbon dioxide fire extinguishing system requirements...Prevention Requirements § 167.45-45 Carbon dioxide fire extinguishing system requirements. (a) When a carbon dioxide (CO2 ) smothering...

2014-10-01

247

46 CFR 97.37-9 - Carbon dioxide and clean agent alarms.  

Code of Federal Regulations, 2014 CFR

... 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 97.37-9...Emergency Equipment, Etc. § 97.37-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire extinguishing...

2014-10-01

248

46 CFR 196.37-9 - Carbon dioxide and clean agent alarms.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 196...Equipment, etc. § 196.37-9 Carbon dioxide and clean agent alarms. Each extinguishing system using carbon dioxide or clean agent complying...

2014-10-01

249

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

Code of Federal Regulations, 2014 CFR

...transportation of hazardous liquids or carbon dioxide. 195.4 Section 195.4...transportation of hazardous liquids or carbon dioxide. No person may transport any hazardous liquid or carbon dioxide unless the hazardous liquid...

2014-10-01

250

46 CFR 78.47-9 - Carbon dioxide and clean agent alarms.  

Code of Federal Regulations, 2014 CFR

... 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 78.47-9...Emergency Equipment, Etc. § 78.47-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire extinguishing...

2014-10-01

251

46 CFR 78.47-9 - Carbon dioxide and clean agent alarms.  

Code of Federal Regulations, 2012 CFR

... 2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms. 78.47-9...Emergency Equipment, Etc. § 78.47-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire extinguishing...

2012-10-01

252

46 CFR 131.815 - Carbon dioxide and clean agent alarms.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 131.815...Equipment and Emergency Equipment § 131.815 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire extinguishing...

2013-10-01

253

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.

254

Chemical Reactions in Supercritical Carbon Dioxide  

NASA Astrophysics Data System (ADS)

Utilizing supercritical fluids as environmentally benign solvents for chemical synthesis is one of the new approaches in the "greening" of chemistry. Carbon dioxide is the most widely used gas for supercritical fluid studies because of its moderate critical constants, nontoxic nature, and availability in pure form. One unique property of supercritical carbon dioxide (sc-CO2) is its high solubility for fluorinated compounds. Thus sc-CO2 can be used to replace Freons that are conventionally used as solvents for synthesis of perfluoro-polymers. Another property of sc-CO2 is its miscibility with gases such as H2. Heterogeneous reactions involving these gases may become homogeneous reactions in sc-CO2. Reactions in sc-CO2 may offer several advantages including controlling phase behavior and products, increasing speed of reactions, and obtaining specific reaction channels. This paper describes the following nine types of chemical reactions reported in the literature utilizing sc-CO2 as a solvent to illustrate the unique properties of the supercritical fluid reaction systems: (i) hydrogenation and hydroformylation, (ii) synthesis of organometallic compounds, (iii) metal chelation and extraction, (iv) preparation of inorganic nanoparticles, (v) stereo-selectivity of lipase-catalyzed reactions, (vi) asymmetric catalytic hydrogenation, (vii) polymerization, (viii) Diels-Alder reaction, and (ix) free radical reactions.

Wai, Chien M.; Hunt, Fred; Ji, Min; Chen, Xiaoyuan

1998-12-01

255

Distributed feedback laser biosensor incorporating a titanium dioxide nanorod surface  

E-print Network

Distributed feedback laser biosensor incorporating a titanium dioxide nanorod surface Chun Ge,1 the label-free detection sensitivity of a vertically-emitting distributed feedback laser biosensor DFBLB with respect to the surrounding liquid media will increase the laser wavelength in proportion to the density

Cunningham, Brian

256

Carbon Dioxide Fluxes in European Russia  

NASA Astrophysics Data System (ADS)

Measurements of carbon balance of boreal ecosystems in the southern taiga of European Russia have been conducted using eddy covariance technique starting from 1998 to the present. The method allows to continuously collect net ecosystem exchange (NEE) fluxes of water and heat between forest and atmosphere with high time resolution. Simultaneous measurements of atmospheric meteorological parameters are carried out. The studies have been conducted in the Tver Region, Russia (Central Forest Biosphere Nature Reserve, 56N, 33E) using a 29 m high tower in low-productive wet spruce forest (P. Sphagnum forest, WSF), a 44 m high tower in high- productive complex spruce forest (CSF) and under the surface of ombrotrophic bog. Eddy flux measurements during limited time intervals are supplemented by measurements of soil, leaves and trunks respiration. Observations of decomposition speed of organic material and the rating NPP are conducted as well. In general, the measurements period has captured a wide range of changes of climatic conditions. Years with extreme dry and damp vegetative seasons and years with close to average climatic conditions for this region fall into the period of observations. The results of our measurements show that unmanaged uneven-aged spruce forests can be both source and sink of carbon to the atmosphere depending on the type of forest and weather conditions. Soil respiration as a result of decomposition of the abundant dead surface- and underground biomass determines the sign and absolute mean of the carbon balance. The overall annual balance of carbon of the studied forest ecosystems differs from zero. The cumulative total of the NEE fluxes for the period of April to October depends first of all on spring temperature and precipitation with temperature being within the range of 5-10C and on the duration of this period. For the period of active vegetation, when air temperature is higher than 10C - the NEE flux depends on humidity. We found significant seasonal and interannual variability of carbon dioxide fluxes for the ombrotrophic bog. The sign and the mean of carbon dioxide fluxes between the surface of the bog and the atmosphere depend on humidity conditions during the green season. When the water balance is negative the ombotrophic bog becomes a source of carbon for the atmosphere.

Kurbatova, J.; Varlagin, A.; Vygodskaya, N.

2007-12-01

257

Hydrodynamic Controls on Carbon Dioxide Efflux from Inland Waters  

NASA Astrophysics Data System (ADS)

Intensive research has been undertaken on carbon dioxide efflux from lakes, estuaries and oceans, but much less attention has been given to rivers and streams, especially lower order streams. River systems are often over-saturated with carbon dioxide and so tend to act as sources of carbon dioxide to the atmosphere. It has been thought that rivers act as pipes carrying this terrestrial carbon to the oceans. However, recent studies have shown that a significant amount of the carbon is reprocessed within the system in a series of transformations and losses. Fluvial evasion of carbon dioxide is now recognised to be a significant component of carbon cycles, however the factors controlling carbon dioxide efflux and its magnitude remain poorly understood and quantified. This research aims to quantify, and better understand the controls on, freshwater carbon dioxide evasion. Data are presented here from field measurements that commenced in Sept 2013 in two contrasting Scottish rivers: the River Kelvin which has a large (335 km.sq) part-urban catchment with predominantly non-peat soils and Drumtee Water, a small (9.6 km.sq) rural catchment of peat soils and agricultural land. Using a floating chamber with the headspace connected to an infrared gas analyser to measure changes in carbon dioxide concentration, efflux rates from 0.22 - 47.4 ?mol CO2/m.sq/sec were measured, these close to the middle of the range of previously reported values. At one site on the River Kelvin in May 2013 an influx of -0.61 - -3.53 ?mol CO2/m.sq/sec was recorded. Whereas previous research finds carbon dioxide efflux to increase with decreasing river size and a more organic-rich soil catchment, here the controls on carbon dioxide evasion are similar across the contrasting catchments. Carbon dioxide evasion shows seasonality, with maximum fluxes in the summer months being up to twice as high as the winter maxima. Linear regression demonstrates that evasion increases with increased flow velocity, water surface disturbance indicated by Froude number, and turbulent mixing indicated by Reynolds number. Similar relationships with season, flow velocity and turbulence have been reported previously, but there is little known about the mechanisms involved. When comparing spot carbon dioxide efflux measurements to river stage time series data, carbon dioxide efflux is more sensitive to an increase in stage at more turbulent measurement points. Further investigation of the mechanisms will be obtained by measurement of DIC concentration and isotopic composition to assess the controls of carbon source versus degassing, and the analysis of the interactions between hydraulic and seasonal controls and carbon dioxide fluxes extended.

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

2013-12-01

258

Mechanistical studies on the formation of carbon dioxide in extraterrestrial carbon monoxide ice analog samples  

E-print Network

Mechanistical studies on the formation of carbon dioxide in extraterrestrial carbon monoxide ice with extraterrestrial, carbon monoxide bearing ices. The chemical modifications were monitored on line and in situ via of carbon monoxide and on the formation of carbon dioxide in extraterrestrial ice analog samples. 1

Kaiser, Ralf I.

259

Carbon dioxide emission during forest fires ignited by lightning  

E-print Network

In this paper we developed the model for the carbon dioxide emission from forest fire. The master equation for the spreading of the carbon dioxide to atmosphere is the hyperbolic diffusion equation. In the paper we study forest fire ignited by lightning. In that case the fores fire has the well defined front which propagates with finite velocity.

Pelc, Magdalena

2009-01-01

260

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

E-print Network

Carbon Dioxide, Global Warming, and Michael Crichton's "State of Fear" Bert W. Rust Mathematical- tioned the connection between global warming and increasing atmospheric carbon dioxide by pointing out of these plots to global warming have spilled over to the real world, inviting both praise [4, 17] and scorn [15

Rust, Bert W.

261

Carbon Dioxide and Global Warming: A Failed Experiment  

ERIC Educational Resources Information Center

Global warming is a current environmental issue that has been linked to an increase in anthropogenic carbon dioxide in the atmosphere. To raise awareness of the problem, various simple experiments have been proposed to demonstrate the effect of carbon dioxide on the planet's temperature. This article describes a similar experiment, which…

Ribeiro, Carla

2014-01-01

262

Performance of air filters cleaned by supercritical carbon dioxide  

Microsoft Academic Search

A new technique based on the use of supercritical carbon dioxide (CO2) for cleaning HEPA filters was developed. Glass fiber filters and polytetrafluoroethylene (PTFE) membranes loaded with dioctylphthalate (DOP) droplets were cleaned with supercritical carbon dioxide under various conditions. The cleaning performance was evaluated by the weight recovery of the filter media and the recoveries of their collection efficiencies and

Takao Ito; Yoshio Otani; Hiroshi Inomata

2004-01-01

263

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

Code of Federal Regulations, 2013 CFR

(a) Carbon dioxide, solid (dry ice), when offered for transportation or transported by aircraft or water, must be packed in packagings designed and constructed to permit the release of carbon dioxide gas to prevent a buildup of pressure that could rupture the...

2013-10-01

264

21 CFR 868.5300 - Carbon dioxide absorbent.  

Code of Federal Regulations, 2013 CFR

A carbon dioxide absorbent is a device intended for medical purposes that consists of an absorbent material (e.g., soda lime) that is intended to remove carbon dioxide from the gases in the breathing circuit. (b) Classification. Class I (general...

2013-04-01

265

21 CFR 868.5310 - Carbon dioxide absorber.  

Code of Federal Regulations, 2013 CFR

A carbon dioxide absorber is a device that is intended for medical purposes and that is used in a breathing circuit as a container for carbon dioxide absorbent. It may include a canister and water drain. (b) Classification. Class I (general...

2013-04-01

266

Climate Science in a Nutshell: Where Carbon Dioxide Come From?  

NSDL National Science Digital Library

This short video discusses where carbon dioxide, the gas that is mainly responsible for warming up our planet and changing the climate, comes from. It discusses how the rise in atmospheric carbon dioxide comes directly from the burning of fossil fuels and indirectly from the human need for energy.

Planet Nutshell

267

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...

268

Blended polymer materials extractable with supercritical carbon dioxide  

Microsoft Academic Search

Supercritical carbon dioxide is drawing more and more attention because of its unique solvent properties along with being environmentally friendly. Historically most of the commercial interests of supercritical carbon dioxide extraction are in the food industry, pharmaceutical industry, environmental preservation and polymer processing. Recently attention has shifted from the extraction of relatively simple molecules to more complex systems with a

Mei Cai

1999-01-01

269

Urban Evapotranspiration and Carbon Dioxide Flux in Miami - Dade, Florida  

Microsoft Academic Search

Atmospheric Carbon Dioxide (CO2) concentrations are leading indicators of secular climate change. With increasing awareness of the consequences of climate change, methods for monitoring this change are becoming more important daily. Of particular interest is the carbon dioxide exchange between natural and urban landscapes and the correlation of atmospheric CO2 concentrations. Monitoring Evapotranspiration (ET) is important for assessments of water

T. Bernier; W. Hopper

2010-01-01

270

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

271

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

272

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

273

ORNL/CDIAC-143 CARBON DIOXIDE, HYDROGRAPHIC, AND CHEMICAL DATA OBTAINED DURING THE  

E-print Network

Kozyr Carbon Dioxide Information Analysis Center Oak Ridge National Laboratory Oak Ridge, Tennessee, U Prepared by the Carbon Dioxide Information Analysis Center OAK RIDGE NATIONAL LABORATORY Oak Ridge

274

Global carbon dioxide emissions from inland waters.  

PubMed

Carbon dioxide (CO2) transfer from inland waters to the atmosphere, known as CO2 evasion, is a component of the global carbon cycle. Global estimates of CO2 evasion have been hampered, however, by the lack of a framework for estimating the inland water surface area and gas transfer velocity and by the absence of a global CO2 database. Here we report regional variations in global inland water surface area, dissolved CO2 and gas transfer velocity. We obtain global CO2 evasion rates of 1.8(+0.25)(-0.25)? petagrams of carbon (Pg?C) per year from streams and rivers and 0.32(+0.52)(-0.26)? Pg?C?yr(-1) from lakes and reservoirs, where the upper and lower limits are respectively the 5th and 95th confidence interval percentiles. The resulting global evasion rate of 2.1?Pg?C?yr(-1) is higher than previous estimates owing to a larger stream and river evasion rate. Our analysis predicts global hotspots in stream and river evasion, with about 70 per cent of the flux occurring over just 20 per cent of the land surface. The source of inland water CO2 is still not known with certainty and new studies are needed to research the mechanisms controlling CO2 evasion globally. PMID:24256802

Raymond, Peter A; Hartmann, Jens; Lauerwald, Ronny; Sobek, Sebastian; McDonald, Cory; Hoover, Mark; Butman, David; Striegl, Robert; Mayorga, Emilio; Humborg, Christoph; Kortelainen, Pirkko; Dürr, Hans; Meybeck, Michel; Ciais, Philippe; Guth, Peter

2013-11-21

275

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

2012-07-14

276

Cooling Heat Transfer of Supercritical Carbon Dioxide  

NASA Astrophysics Data System (ADS)

The characteristics of carbon dioxide cooled under supercritical condition were investigated theoretically and experimentally. Based on the results of numerical calculation and experimental measurements described in the 1st report, a new correlation was proposed to predict the heat transfer coefficient, and the Filonenko's equation was found adequate to predict the pressure drop inside as mall seized tube. Those correlations were compared with measurement results and the deviations were found lower than ±20%. Furthermore, a compressor cycle was assembled to investigate the effect of lubricant oil on heat transfer and pressure drop. The oil content in CO2 was set to be about 0.5% during the measurements. This amount of lubricant oil was found affected the heat transfer coefficient significantly, with largest degradation of heat transfer coefficient at the pseudocritical point to nearly 50%. The effect of lubricant oil at small concentration on the pressure drop was found negligible.

Dang, Chaobin; Hihara, Eiji

277

Layered solid sorbents for carbon dioxide capture  

DOEpatents

A solid sorbent for the capture and the transport of carbon dioxide gas is provided having at least one first layer of a positively charged material that is polyethylenimine or poly(allylamine hydrochloride), that captures at least a portion of the gas, and at least one second layer of a negatively charged material that is polystyrenesulfonate or poly(acryclic acid), that transports the gas, wherein the second layer of material is in juxtaposition to, attached to, or crosslinked with the first layer for forming at least one bilayer, and a solid substrate support having a porous surface, wherein one or more of the bilayers is/are deposited on the surface of and/or within the solid substrate. A method of preparing and using the solid sorbent is provided.

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

2014-11-18

278

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

279

Does carbon dioxide pool or stream in the subsurface?  

E-print Network

Pools of carbon dioxide are found in natural geological accumulations and in engineered storage in saline aquifers. It has been thought that once this CO2 dissolves in the formation water, making it denser, convection streams would transport it efficiently to depth, but this may not be so. Here, we assess the impact of natural chemical reactions between the dissolved CO2 and the rock formation on the convection streams in the subsurface. We show that, while in carbonate rocks the streaming of dissolved carbon dioxide persists, the chemical interactions in silicate-rich rocks may curb this transport drastically and even inhibit it altogether. New laboratory experiments confirm the curtailing of convection by reaction. Wide and narrow streams of dense carbon-rich water are shut-off gradually as reaction strength increases until all transport of the pooled carbon dioxide occurs by slow molecular diffusion. These results show that the complex fluid dynamic and kinetic interactions between pooled carbon dioxide an...

Cardoso, Silvana S S

2014-01-01

280

Coiled tubing drilling with supercritical carbon dioxide  

DOEpatents

A method for increasing the efficiency of drilling operations by using a drilling fluid material that exists as supercritical fluid or a dense gas at temperature and pressure conditions existing at a drill site. The material can be used to reduce mechanical drilling forces, to remove cuttings, or to jet erode a substrate. In one embodiment, carbon dioxide (CO.sub.2) is used as the material for drilling within wells in the earth, where the normal temperature and pressure conditions cause CO.sub.2 to exist as a supercritical fluid. Supercritical carbon dioxide (SC--CO.sub.2) is preferably used with coiled tube (CT) drilling equipment. The very low viscosity SC--CO.sub.2 provides efficient cooling of the drill head, and efficient cuttings removal. Further, the diffusivity of SC--CO.sub.2 within the pores of petroleum formations is significantly higher than that of water, making jet erosion using SC--CO.sub.2 much more effective than water jet erosion. SC--CO.sub.2 jets can be used to assist mechanical drilling, for erosion drilling, or for scale removal. A choke manifold at the well head or mud cap drilling equipment can be used to control the pressure within the borehole, to ensure that the temperature and pressure conditions necessary for CO.sub.2 to exist as either a supercritical fluid or a dense gas occur at the drill site. Spent CO.sub.2 can be vented to the atmosphere, collected for reuse, or directed into the formation to aid in the recovery of petroleum.

Kolle , Jack J. (Seattle, WA)

2002-01-01

281

Carbon dioxide exchange and growth of a pine plantation  

SciTech Connect

The exchange of materials between the atmosphere and terrestrial ecosystem is important to an understanding of the cycling of essential elements, the deposition of mateials from the atmosphere and the entrance of pollutants into the forest ecosystems. This paper reports the results of measurements of carbon dioxide exchange in a vigorously growing pine plantation. Measurement data were incorporated into a model used to estimate annual carbon dioxide exchange and measured annual biomass accumulation in the same plantation were used to determine a carbon dioxide to biomass conversion efficiency. Carbon dioxide exchange was 10.5 metric tons per hectare and biomass accumulation was 4.5 metric tons per hectare. The conversion efficiency of cabon dioxide to biomass is about 25% less than the theoretical chemical conversion efficiency. 27 refs., 8 figs.

Murphy, Jr, C E

1981-01-01

282

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

283

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

284

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

285

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

286

Carbon dioxide warming of the early Earth  

NASA Technical Reports Server (NTRS)

Svante Arrhenius' research in atmospheric physics extended beyond the recent past and the near future states of the Earth, which today are at the center of sociopolitical attention. His plan encompassed all of the physical phenomena known at the time to relate to the formation and evolution of stars and planets. His two-volume textbook on cosmic physics is a comprehensive synopsis of the field. The inquiry into the possible cause of the ice ages and the theory of selective wavelength filter control led Arrhenius to consider the surface states of the other terrestrial planets, and of the ancient Earth before it had been modified by the emergence of life. The rapid escape of hydrogen and the equilibration with igneous rocks required that carbon in the early atmosphere prevailed mainly in oxidized form as carbon dioxide, together with other photoactive gases exerting a greenhouse effect orders of magnitude larger than in our present atmosphere. This effect, together with the ensuing chemical processes, would have set the conditions for life to evolve on our planet, seeded from spores spreading through an infinite Universe, and propelled, as Arrhenius thought, by stellar radiation pressure.

Arrhenius, G.

1997-01-01

287

Carbon dioxide warming of the early Earth.  

PubMed

Svante Arrhenius' research in atmospheric physics extended beyond the recent past and the near future states of the Earth, which today are at the center of sociopolitical attention. His plan encompassed all of the physical phenomena known at the time to relate to the formation and evolution of stars and planets. His two-volume textbook on cosmic physics is a comprehensive synopsis of the field. The inquiry into the possible cause of the ice ages and the theory of selective wavelength filter control led Arrhenius to consider the surface states of the other terrestrial planets, and of the ancient Earth before it had been modified by the emergence of life. The rapid escape of hydrogen and the equilibration with igneous rocks required that carbon in the early atmosphere prevailed mainly in oxidized form as carbon dioxide, together with other photoactive gases exerting a greenhouse effect orders of magnitude larger than in our present atmosphere. This effect, together with the ensuing chemical processes, would have set the conditions for life to evolve on our planet, seeded from spores spreading through an infinite Universe, and propelled, as Arrhenius thought, by stellar radiation pressure. PMID:11541253

Arrhenius, G

1997-02-01

288

Forest management techniques for carbon dioxide storage  

SciTech Connect

In the global ecosystem concerning carbon dioxide content in the atmosphere, the forest ecosystem plays an important role. In effect, the ratio of forest biomass to total terrestrial biomass is about 90%, and the ratio of carbon stored in the forest biomass to that in the atmosphere is two thirds. When soils and detritus of forests are added, there is more C stored in forests than in the atmosphere, about 1.3 times or more. Thus, forests can be regarded as the great holder of C on earth. If the area of forest land on the earth is constantly maintained and forests are in the climax stage, the uptake of C and the release of C by and from the forests will balance. In this case, forests are neither sinks nor sources of CO{sub 2} although they store a large amount of C. However, when forests are deforested, they become a source of C; through human activities, forests have become a source of C. According to a report by the IPCC, 1.6{+-}1.2 PgC is annually added to the atmosphere by deforestation. According to the FAO (1992), the area of land deforested annually in the tropics from 1981 to 1990 was 16.9 x 10{sup 6} ha. This value is nearly half the area of Japanese land. The most important thing for the CO{sub 2} environment concerning forests is therefore how to reduce deforestation and to successfully implement a forestation or reforestation.

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

1993-12-31

289

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

DOEpatents

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.; Bourcier, William L.

2014-08-19

290

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

DOEpatents

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

291

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

292

Separation of Carbon Monoxide and Carbon Dioxide for Mars ISRU  

NASA Technical Reports Server (NTRS)

The atmosphere of Mars has many resources that can be processed to produce things such as oxygen, fuel, buffer gas, and water for support of human exploration missions. Successful manipulation of these resources is crucial for safe, cost-effective, and self-sufficient long-term human exploration of Mars. In our research, we are developing enabling technologies that require fundamental knowledge of adsorptive gas storage and separation processes. In particular, we are designing and constructing an innovative, low mass, low power separation device to recover carbon dioxide and carbon monoxide for Mars ISRU (in-situ resource utilization). The technology has broad implications for gas storage and separations for gas-solid systems that are ideally suited for reduced gravitational environments. This paper describes our separation process design and experimental procedures and reports results for the separation of CO2 and CO by a four-step adsorption cycle.

Walton, Krista S.; LeVan, M. Douglas

2004-01-01

293

Thermal Infrared Radiation and Carbon Dioxide in the Atmosphere  

E-print Network

Thermal Infrared Radiation and Carbon Dioxide in the Atmosphere Bill Satzer 3M Company #12;Outline · Radiation spectra ­ incoming and outgoing · Physical setting ­ characteristics of the atmosphere · CO2 dioxide Water vapor #12;Atmospheric composition (parts per million by volume) · Nitrogen (N2) 780

Olver, Peter

294

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

295

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

296

Synthesis of Amides and Lactams in Supercritical Carbon Dioxide  

E-print Network

Supercritical carbon dioxide can be employed as an environmentally friendly alternative to conventional organic solvents for the synthesis of a variety of carboxylic amides. The addition of amines to ketenes generated in ...

Mak, Xiao Yin

297

World energy consumption and carbon dioxide emissions : 1950-2050  

E-print Network

Emissions of carbon dioxide form combustion of fossil fuels, which may contribute to long-term climate change, are projected through 2050 using reduced form models estimated with national-level panel data for the period ...

Schmalensee, Richard

1995-01-01

298

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

NASA Technical Reports Server (NTRS)

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

Johnson, F. S.

1975-01-01

299

Atmospheric concentrations of carbon dioxide, methane and nitrous oxide  

NSDL National Science Digital Library

This is a figure from the 2007 IPCC Assessment Report 4 on atmospheric concentrations of carbon dioxide, methane and nitrous oxide over the last 10,000 years (large panels) and since 1750 (inset panels).

IPCC (Intergovernmental Panel of Climate Change)

300

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...

301

Control strategies for supercritical carbon dioxide power conversion systems  

E-print Network

The supercritical carbon dioxide (S-C02) recompression cycle is a promising advanced power conversion cycle which couples well to numerous advanced nuclear reactor designs. This thesis investigates the dynamic simulation ...

Carstens, Nathan, 1978-

2007-01-01

302

Separation of carbon dioxide from flue emissions using Endex principles  

E-print Network

In an Endex reactor endothermic and exothermic reactions are directly thermally coupled and kinetically matched to achieve intrinsic thermal stability, efficient conversion, autothermal operation, and minimal heat losses. Applied to the problem of in-line carbon dioxide separation from flue gas, Endex principles hold out the promise of effecting a carbon dioxide capture technology of unprecedented economic viability. In this work we describe an Endex Calcium Looping reactor, in which heat released by chemisorption of carbon dioxide onto calcium oxide is used directly to drive the reverse reaction, yielding a pure stream of carbon dioxide for compression and geosequestration. In this initial study we model the proposed reactor as a continuous-flow dynamical system in the well-stirred limit, compute the steady states and analyse their stability properties over the operating parameter space, flag potential design and operational challenges, and suggest an optimum regime for effective operation.

Ball, R

2009-01-01

303

Effect of Electronarcosis on Oxygen Consumption and Carbon Dioxide Output  

Microsoft Academic Search

IN assessing changes of vital function during electronarcosis, we measured oxygen consumption and carbon dioxide output in an experiment in rabbits. The measured values were considered an important index for the evaluation of metabolic changes during electronarcosis.

Jaroslav Strmiska; Antonín Vacek

1960-01-01

304

9 CFR 313.5 - Chemical; carbon dioxide.  

Code of Federal Regulations, 2014 CFR

...by the elimination of sharp projections or exposed wheels or gears. There shall be no unnecessary holes, spaces or openings...gas supplied to anesthesia chambers may be from controlled reduction of solid carbon dioxide or from a controlled liquid...

2014-01-01

305

DEVELOPMENT AND INTEGRATION OF NEW PROCESSES CONSUMING CARBON DIOXIDE IN  

E-print Network

............................................................... 3 B. Greenhouse Effect and Climate Change............................................. 4 1. Estimation of Greenhouse Gas Emissions....................................... 6 2. Greenhouse Gas Emissions........................................................ 8 C. Carbon Dioxide ­ A Greenhouse Gas................................................ 9 1. Sources

Pike, Ralph W.

306

Electrochemically-mediated amine regeneration for carbon dioxide separations  

E-print Network

This thesis describes a new strategy for carbon dioxide (CO?) separations based on amine sorbents, which are electrochemically-mediated to facilitate the desorption and regeneration steps of the separation cycle. The ...

Stern, Michael C. (Michael Craig)

2014-01-01

307

Submarine seep of carbon dioxide in Norton Sound, Alaska  

USGS Publications Warehouse

Earlier workers have described a submarine gas seep in Norton Sound having an unusual mixture of petroleum-like, low-molecular-weight hydrocarbons. Actually, only about 0.04 percent of the seeping gas is hydrocarbons and 98 percent is carbon dioxide. The isotopic compositions of carbon dioxide (??13CPDB = -2.7 per mil) and methane (??13CPDB = -36 per mil, where PDB is the Peedee belemnite standard) indicate that geothermal processes are active here. Copyright ?? 1979 AAAS.

Kvenvolden, K.A.; Weliky, K.; Nelson, H.; Des Marais, D.J.

1979-01-01

308

Tethered catalysts for the hydration of carbon dioxide  

SciTech Connect

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

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

2014-11-04

309

Extraction of lemongrass essential oil with dense carbon dioxide  

Microsoft Academic Search

Lemongrass (Cymbopogon citratus) essential oil was extracted with dense carbon dioxide at 23–50°C and 85–120 bar. The composition of samples collected during the first and the last hours of the extraction experiments was analyzed by gas chromatography–mass spectrometry, and coextraction of cuticular waxes was observed. Liquid carbon dioxide extracts had a larger quantity of coextracted waxes than the supercritical extracts.

Luiz Henrique Castelan Carlson; Ricardo Antonio Francisco Machado; Cinthia Bittencourt Spricigo; Lia Krücken Pereira; Ariovaldo Bolzan

2001-01-01

310

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

311

Methanolysis of seed oils in flowing supercritical carbon dioxide  

Microsoft Academic Search

The direct methanolysis of triglycerides in flowing supercritical carbon dioxide by an immobilized lipase is described. The\\u000a reaction system consists of two syringe pumps for substrate addition and another two syringe pumps for delivering CO2 at 24.1 MPa. Corn oil is pumped into the carbon dioxide stream at a rate of 4 ?L\\/min, and methanol is pumped at 5 ?L\\/min

Michael A. Jackson; Jerry W. King

1996-01-01

312

ABSORPTION OF CARBON DIOXIDE INTO AQUEOUS DIETHANOLAMINE SOLUTIONS  

Microsoft Academic Search

The rates of absorption of pure carbon dioxide into aqueous diethanolamine solutions were measured at 25C in a liquid-jet column and a wetted-wall column. Experimental results were analyzed with the chemical absorption theory based on the penetration model. Physical solubility of carbon dioxide in aqueous diethanolamine solutions was determined from the absorption rates measured in a near pseudo first-order reaction

H. HIKITA; S. ASAI; H. ISHIKAWA; K. UKU

1980-01-01

313

Beneficial Use of Carbon Dioxide in Precast Concrete Production  

SciTech Connect

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

Shao, Yixin

2014-03-31

314

Miniaturized Amperometric Solid Electrolyte Carbon Dioxide Sensors  

NASA Technical Reports Server (NTRS)

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

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

2006-01-01

315

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

316

Carbon dioxide dynamics in an artificial ecosystem  

NASA Astrophysics Data System (ADS)

An experimental artificial ecosystem was established as a tool to understand the behavior of closed ecosystem and to develop the technology for a future bioregenerative life support system for lunar or planetary exploration. Total effective volume of the system is 0.7 m3 . It consists of a higher plant chamber, an animal chamber and a photo-bioreactor which cultivated lettuce (Lactuca sativa L.), silkworm (Bombyx Mori L.) and microalgae (Chlorella), respectively. For uniform and sustained observations, lettuce and silkworms was cultivated using sequential cultivation method, and microalgae using continuous culture. Four researchers took turns breathing the system air through a tube for brief periods every few hours. A mathematic model, simulating the carbon dioxide dynamics was developed. The main biological parameters concerning photosynthesis of lettuce and microalgae, respiration of silkworms and human were validated by the experimental data. The model described the respiratory relationship between autotrophic and heterotrophic compartments. A control strategy was proposed as a tool for the atmosphere management of the artificial ecosystem.

Hu, Enzhu; Hu, Dawei; Tong, Ling; Li, Ming; Fu, Yuming; He, Wenting; Liu, Hong

317

Euthanasia of neonatal mice with carbon dioxide  

USGS Publications Warehouse

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

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

2005-01-01

318

Suppressing bullfrog larvae with carbon dioxide  

USGS Publications Warehouse

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

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

2014-01-01

319

Electrocatalytic Reduction of Carbon Dioxide to Methane  

NASA Technical Reports Server (NTRS)

A room-temperature electrocatalytic process that effects the overall chemical reaction CO2 + 2H2O yields CH4 + 2O2 has been investigated as a means of removing carbon dioxide from air and restoring oxygen to the air. The process was originally intended for use in a spacecraft life-support system, in which the methane would be vented to outer space. The process may also have potential utility in terrestrial applications in which either or both of the methane and oxygen produced might be utilized or vented to the atmosphere. A typical cell used to implement the process includes a polymer solid-electrolyte membrane, onto which are deposited cathode and anode films. The cathode film is catalytic for electrolytic reduction of CO2 at low overpotential. The anode film is typically made of platinum. When CO2 is circulated past the cathode, water is circulated past the anode, and a suitable potential is applied, the anode half-cell reaction is 4H2O yields 2O2 + 8H(+) + 8e(-). The H(+) ions travel through the membrane to the cathode, where they participate in the half-cell reaction CO2 + 8H(+) + 8e(-) yields CH4 + 2H2O.

Sammells, Anthony F.; Spiegel, Ella F.

2008-01-01

320

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

321

Effects of carbon dioxide on laryngeal receptors  

SciTech Connect

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

Anderson, J.W.; Sant'Ambrogio, F.B.; Orani, G.P.; Sant'Ambrogio, G.; Mathew, O.P. (Univ. of Texas, Galveston (United States))

1990-02-26

322

The role of renewable bioenergy in carbon dioxide sequestration  

SciTech Connect

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

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

1993-12-31

323

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

324

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

325

Carbon Dioxide Reduction Technology Trade Study  

NASA Technical Reports Server (NTRS)

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

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

2011-01-01

326

A selective and efficient electrocatalyst for carbon dioxide reduction  

NASA Astrophysics Data System (ADS)

Converting carbon dioxide to useful chemicals in a selective and efficient manner remains a major challenge in renewable and sustainable energy research. Silver is an interesting electrocatalyst owing to its capability of converting carbon dioxide to carbon monoxide selectively at room temperature; however, the traditional polycrystalline silver electrocatalyst requires a large overpotential. Here we report a nanoporous silver electrocatalyst that is able to electrochemically reduce carbon dioxide to carbon monoxide with approximately 92% selectivity at a rate (that is, current) over 3,000 times higher than its polycrystalline counterpart under moderate overpotentials of <0.50?V. The high activity is a result of a large electrochemical surface area (approximately 150 times larger) and intrinsically high activity (approximately 20 times higher) compared with polycrystalline silver. The intrinsically higher activity may be due to the greater stabilization of CO2?- intermediates on the highly curved surface, resulting in smaller overpotentials needed to overcome the thermodynamic barrier.

Lu, Qi; Rosen, Jonathan; Zhou, Yang; Hutchings, Gregory S.; Kimmel, Yannick C.; Chen, Jingguang G.; Jiao, Feng

2014-01-01

327

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

328

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

329

Master/Diploma project Degradation of carbon dioxide by micro organisms  

E-print Network

microorganisms can use carbon dioxide as carbon source for their life cycle. Whereas plants are the main sourceMaster/Diploma project Degradation of carbon dioxide by micro organisms The accumulation of carbon of the carbon dioxide release is an important objective in the near future. Various strategies are discussed

Rostock, Universität

330

Ionic Liquid Membranes for Carbon Dioxide Separation  

SciTech Connect

Recent scientific studies are rapidly advancing novel technological improvements and engineering developments that demonstrate the ability to minimize, eliminate, or facilitate the removal of various contaminants and green house gas emissions in power generation. The Integrated Gasification Combined Cycle (IGCC) shows promise for carbon dioxide mitigation not only because of its higher efficiency as compared to conventional coal firing plants, but also due to a higher driving force in the form of high partial pressure. One of the novel technological concepts currently being developed and investigated is membranes for carbon dioxide (CO2) separation, due to simplicity and ease of scaling. A challenge in using membranes for CO2 capture in IGCC is the possibility of failure at elevated temperatures or pressures. Our earlier research studies examined the use of ionic liquids on various supports for CO2 separation over the temperature range, 37°C-300°C. The ionic liquid, 1-hexyl-3methylimidazolium Bis(trifluoromethylsulfonyl)imide, ([hmim][Tf2N]), was chosen for our initial studies with the following supports: polysulfone (PSF), poly(ether sulfone) (PES), and cross-linked nylon. The PSF and PES supports had similar performance at room temperature, but increasing temperature caused the supported membranes to fail. The ionic liquid with the PES support greatly affected the glass transition temperature, while with the PSF, the glass transition temperature was only slightly depressed. The cross-linked nylon support maintained performance without degradation over the temperature range 37-300°C with respect to its permeability and selectivity. However, while the cross-linked nylon support was able to withstand temperatures, the permeability continued to increase and the selectivity decreased with increasing temperature. Our studies indicated that further testing should examine the use of other ionic liquids, including those that form chemical complexes with CO2 based on amine interactions. The hypothesis is that the performance at the elevated temperatures could be improved by allowing a facilitated transport mechanism to become dominant. Several amine-based ionic liquids were tested on the cross-linked nylon support. It was found that using the amine-based ionic liquid did improve selectivity and permeability at higher temperature. The hypothesis was confirmed, and it was determined that the type of amine used also played a role in facilitated transport. Given the appropriate aminated ionic liquid with the cross-linked nylon support, it is possible to have a membrane capable of separating CO2 at IGCC conditions. With this being the case, the research has expanded to include separation of other constituents besides CO2 (CO, H2S, etc.) and if they play a role in membrane poisoning or degradation. This communication will discuss the operation of the recently fabricated ionic liquid membranes and the impact of gaseous components other than CO2 on their performance and stability.

Myers, C.R.; Ilconich, J.B.; Luebke, D.R.; Pennline, H.W.

2008-07-12

331

14 April 2001 tmospheric carbon dioxide  

E-print Network

emissions is through increased carbon sequestration into forests. In a large-scale assessment, Birdsey- ing carbon sequestration in southern forests. Carbon sequestration via southern pine forests may policy commitments. Keywords: carbon sequestration; southern pine forests ABSTRACT MEETING GLOBAL POLICY

Teskey, Robert O.

332

The carbon dioxide challenge facing aviation  

NASA Astrophysics Data System (ADS)

This paper investigates the challenge that U.S. aviation would face in meeting future Greenhouse Gas (GHG) reduction goals to mitigate global climate change via technological options. This investigation is done within a framework that considers aviation GHG emissions as a function of aviation growth, aircraft efficiency, operational efficiency, and life cycle GHG emissions of aviation fuels. The concept of life cycle GHG intensity (LGI) with units of grams carbon dioxide equivalent per payload distance traveled is used for this purpose as it can be decomposed into components that quantify improvements in aircraft design, operations, and alternative fuels. For example, the life cycle GHG intensity of U.S. aviation in 2005 was 1.37 g CO2e/kg km. If U.S. aviation is to meet the IATA 2050 goal of a 50% reduction in CO2 relative to a 2005 baseline while allowing for a 3.2% annual growth rate in payload-distance traveled, it will need to decrease to 0.22 g CO2e/kg km in 2050, an 84% reduction. The analysis framework that is developed in this manuscript was used to compare the improvements in life cycle GHG intensity that could accompany the use of advanced aircraft designs, operational improvements, and alternative fuels to those required on a fleet-wide basis to meet the future GHG reduction goals under varied aviation growth scenarios. The results indicate that the narrow body segment of the fleet could indeed meet ambitious goals of reducing GHG emissions by 50%, relative to 2005 levels, with a 3.2% annual growth rate; however, it would require relatively rapid adoption of innovative aircraft designs and the widespread use of alternative fuels with relatively low life cycle GHG emissions.

Hileman, James I.; De la Rosa Blanco, Elena; Bonnefoy, Philippe A.; Carter, Nicholas A.

2013-11-01

333

The Headache of Carbon Dioxide Exposures  

NASA Technical Reports Server (NTRS)

Carbon dioxide (CO2), a natural product of human metabolism, accumulates quickly in sealed environments when humans are present, and can induce headaches, among other symptoms. Major resources are expended to control CO2 levels to concentrations that are tolerable to the crews of spacecraft and submersible craft. It is not practical to control CO2 levels to those found in the ambient environment on earth. As NASA looks ahead to long-duration missions conducted far from earth, difficult issues arise related to the management and effects of human exposure to CO2. One is the problem of pockets of CO2 in the habitat caused by excess generation of the gas in one location without a mechanism to purge the area with fresh air. This results in the crew rebreathing CO2 from their exhaled breath, exposing them to a much higher concentration of CO2 than whole-module measurements would suggest. Another issue is the potential increased sensitivity to CO2 in microgravity. For example, based on anecdotal information, it appears that space crews may be more susceptible than submarine crews to some of the subtle, yet adverse effects of CO2 exposure. Another issue, not unique to spaceflight, is the possibility of inter-individual differences in the susceptibility of crewmembers to CO2 exposure. Again, anecdotal reports from the International Space Station (ISS) crews suggest that certain individuals may experience a greater susceptibility. The implications associated with these issues are extremely important as NASA sets CO2 exposure limits that protect the crew from this compound s subtle adverse effects, without causing an unwarranted expenditure of resources to scrub CO2 from the habitat atmosphere.

James, John T.

2007-01-01

334

Carbon dioxide exchange in a peatland ecosystem  

NASA Astrophysics Data System (ADS)

Micrometeorological measurements of carbon dioxide exchange were made in an open peatland in north central Minnesota during two growing seasons (1991 and 1992). The vegetation at the site was dominated by Sphagnum papillosum, Scheuchzeria palustris, and Chamaedaphne calyculata. The objective of the study was to examine the diurnal and seasonal variations in canopy photosynthesis (P) and develop information on the net ecosystem CO2 exchange. The two seasons provided contrasting microclimatic conditions: as compared with 1991, the 1992 season was significantly wetter and cooler. Canopy photosynthesis was sensitive to changes in light, temperature, and moisture stress (as indicated by water table depth and atmospheric vapor pressure deficit). Under moderate conditions (temperature 18-28°C, vapor pressure deficit 0.7-1.5 kPa, and water table near the surface) during the peak growth period, midday (averaged between 1000-1400 hours) P values ranged from 0.15 to 0.24 mg m-2 s-1. Under high-temperature (30°-34°C) and moisture stress (water table 0.16-0.23 m below the surface and vapor pressure deficit 2.2-3.0 kPa) conditions, midday P was reduced to about 0.03-0.06 mg m-2 s-1. There was a high degree of consistency in the values of P under similar conditions in the two seasons. Seasonally integrated values of the daily net ecosystem CO2 exchange indicated that the study site was a source of atmospheric CO2, releasing about 71 g C m-2 over a 145-day period (May-October) in 1991. Over a similar period in 1992, however, this ecosystem was a sink for atmospheric CO2 with a net accumulation of about 32 g C m-2. These results are consistent with previous investigations on CO2 exchange in other northern wetland sites during wet and dry periods.

Shurpali, N. J.; Verma, S. B.; Kim, J.; Arkebauer, T. J.

1995-07-01

335

Carbon Dioxide Carbonates in the Earth;s Mantle: Implications to the Deep Carbon Cycle  

SciTech Connect

An increase in the ionic character in C-O bonds at high pressures and temperatures is shown by the chemical/phase transformation diagram of CO{sub 2}. The presence of carbonate carbon dioxide (i-CO{sub 2}) near the Earth's core-mantle boundary condition provides insights into both the deep carbon cycle and the transport of atmospheric CO{sub 2} to anhydrous silicates in the mantle and iron core.

Yoo, Choong-Shik; Sengupta, Amartya; Kim, Minseob (Princeton); (WSU)

2012-05-22

336

Persistent local order heterogeneity in the supercritical carbon dioxide  

E-print Network

The supercritical state is currently viewed as uniform and homogeneous on the pressure-temperature phase diagram in terms of physical properties. Here, we study structural properties of the supercritical carbon dioxide, and discover the existence of persistent medium-range order correlations which make supercritical carbon dioxide non-uniform and heterogeneous on an intermediate length scale, a result not hitherto anticipated. We report on the carbon dioxide heterogeneity shell structure where, in the first shell, both carbon and oxygen atoms experience gas-like type inter- actions with short range order correlations, while within the second shell oxygen atoms essentially exhibit liquid-like type of interactions with medium range order correlations due to localisation of transverse-like phonon packets. We show that the local order heterogeneity remains in the three phase-like equilibrium within very wide temperature range. Importantly, we highlight a catalytic role of atoms inside the nearest neighbor heterogeneity shell in providing a mechanism for diffusion in the supercritical carbon dioxide on an intermediate length scale. Finally, we discuss important implications for answering the intriguing question whether Venus may have had carbon dioxide oceans and urge for an experimental detection of this persistent local order heterogeneity.

Dima Bolmatov; D. Zav'yalov; M. Gao; M. Zhernenkov

2014-06-06

337

Mar., 1955 GASIFICATIONOF CARBONRODSWITH CARBONDIOXIDE 241 GASIFICATION OF CARBON RODS WITH CARBON DIOXIDE1*2  

E-print Network

Mar., 1955 GASIFICATIONOF CARBONRODSWITH CARBONDIOXIDE 241 GASIFICATION OF CARBON RODS WITH CARBON commercial carbons and their gasification rates with carbon dioxide at a series of temperatures between 900. No general correlation between these properties and the carbon gasification rates was found. Introduction

338

Cobalt carbonyl catalyzed olefin hydroformylation in supercritical carbon dioxide  

DOEpatents

A method of olefin hydroformylation is provided wherein an olefin reacts with a carbonyl catalyst and with reaction gases such as hydrogen and carbon monoxide in the presence of a supercritical reaction solvent, such as carbon dioxide. The invention provides higher yields of n-isomer product without the gas-liquid mixing rate limitation seen in conventional Oxo processes using liquid media.

Rathke, J.W.; Klingler, R.J.

1993-03-30

339

Capturing carbon dioxide as a polymer from natural gas  

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

340

Capturing carbon dioxide as a polymer from natural gas.  

PubMed

Natural gas is considered the cleanest and recently the most abundant fossil fuel source, yet when it is extracted from wells, it often contains 10-20 mol% carbon dioxide (20-40 wt%), which is generally vented to the atmosphere. Efforts are underway to contain this carbon dioxide at the well-head using inexpensive and non-corrosive methods. Here we report nucleophilic porous carbons are synthesized from simple and inexpensive carbon-sulphur and carbon-nitrogen precursors. Infrared, Raman and (13)C nuclear magnetic resonance signatures substantiate carbon dioxide fixation by polymerization in the carbon channels to form poly(CO2) under much lower pressures than previously required. This growing chemisorbed sulphur- or nitrogen-atom-initiated poly(CO2) chain further displaces physisorbed hydrocarbon, providing a continuous carbon dioxide selectivity. Once returned to ambient conditions, the poly(CO2) spontaneously depolymerizes, leading to a sorbent that can be easily regenerated without the thermal energy input that is required for traditional sorbents. PMID:24892923

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

2014-01-01

341

Electrostatic Stabilization of Colloids in Carbon Dioxide: Electrophoresis and Dielectrophoresis  

E-print Network

Electrostatic Stabilization of Colloids in Carbon Dioxide: Electrophoresis and Dielectrophoresis by electrostatic forces, despite the ultralow dielectric constant of 1.5. Zeta potentials of micrometer- sized a dozen droplets with lengths of 50 m. The ability to form electrostatically stabilized colloids in carbon

342

Distribution of and changes in industrial carbon dioxide production  

Microsoft Academic Search

The burning of fossils fuels is believed to be the major source responsible for an observed increase in the concentration of carbon dioxide in the atmosphere now measured at many locations around the world. This paper revises earlier published data on the annual amounts of carbon released to the atmosphere during the period 1950--1978 and updates the record through 1980.

Ralph M. Rotty

1983-01-01

343

II. Greenhouse gas markets, carbon dioxide credits and biofuels17  

E-print Network

15 II. Greenhouse gas markets, carbon dioxide credits and biofuels17 The previous chapter analysed biofuels production. GHG policies18 that create a carbon price either through an emissions trading system or directly by taxing GHG emissions also generate increased demand for biofuels. They do so by raising

344

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

The objective of this project is to develop a simple and inexpensive process to separate CO{sub 2} 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 water vapor. Bicarbonates are regenerated to carbonates when heated, producing a nearly pure CO{sub 2} stream after condensation of water vapor. This quarter, electrobalance tests suggested that higher temperature calcination of trona leds to reduced carbonation activity in subsequent cycles, but that calcination in dry carbon dioxide did not result in decreased activity relative to calcination in helium. Following higher temperature calcination, sodium bicarbonate (SBC) No.3 has greater activity than either coarse or fine grades of trona. Fixed bed testing of calcined SBC No.3 at 70 C confirmed that high rates of carbon dioxide absorption are possible and that the resulting product is a mixture of Wegscheider's salt and sodium carbonate. In fluidized bed testing of supported potassium carbonate, very rapid carbonation rates were observed. Activity of the support material complicated the data analysis. A milled, spherical grade of SBC appeared to be similar in attrition and abrasion characteristics to an unmilled, less regularly shaped SBC. The calcination behavior, at 107 C, for the milled and unmilled materials was also similar.

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

2002-10-01

345

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

SciTech Connect

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

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

1980-04-01

346

Study of redox reactions to split water and carbon dioxide  

NASA Astrophysics Data System (ADS)

The development of carbon-neutral, environmentally-sustainable energy carrier is a technological imperative necessary to mitigate the impact of anthropogenic carbon dioxide on earth's climate. One compelling approach rapidly gaining international attention is the conversion of solar energy into renewable fuels, such as H2 or CO, via a two-step thermochemical cycle driven by concentrated solar power. In accordance with the increased interest in this process, there is a need to better understand the gas splitting chemistry on the metal oxide intermediates encountered in such solar-driven processes. Here we measured the H2 and CO production rates during oxidation by H2O and CO2 in a stagnation flow reactor. Redox cycles were performed over various metal oxide chemistries such as hercynite and ceria based materials that are thermally reduced by laser irradiation. In addition to cycle capacity evaluation, reaction kinetics intrinsic to the materials were extracted using a model-based analytical approach to account for the effects of mixing and dispersion in the reactor. Investigation of the "hercynite chemistry" with raman spectroscopy verifies that, at the surface, the cycle proceeds by stabilizing the reduced and oxidized moieties in two different compounds, which allows the thermal reduction reaction to occur to a greater extent at a temperature 150 °C lower than a similarly prepared CoFe2O4-coated m-ZrO2. Investigation of the ceria cycle shows that the water splitting reaction, in the range of 750 - 950 °C and 20 - 40 vol.% H2O, can best be described by a first-order kinetic model with low apparent activation energy (29 kJ/mol). The carbon dioxide splitting reaction, in the range of 650 - 875 °C and 10 - 40 vol.% CO2, is a more complex surface-mediated phenomena that is controlled by a temperature-dependent surface site blocking mechanism involving adsorbed carbon. Moreover, we find that lattice substitution of ceria with zirconium can increase H2 production by approximately 11 %, and that the kinetics of water splitting on doped ceria is still best described by a deceleratory power law model (F-model), similar to undoped CeO2. Our results fill a critical gap in the knowledge base required to develop high-fidelity computational models for the design of concentrated solar receiver/reactors.

Arifin, Darwin

347

Persistent local order heterogeneity in the supercritical carbon dioxide  

E-print Network

The supercritical state is currently viewed as uniform and homogeneous on the pressure-temperature phase diagram in terms of physical properties. Here, we study structural properties of the supercritical carbon dioxide, and discover the existence of persistent medium-range order correlations which make supercritical carbon dioxide non-uniform and heterogeneous on an intermediate length scale, a result not hitherto anticipated. We report on the carbon dioxide heterogeneity shell structure where, in the first shell, both carbon and oxygen atoms experience gas-like type inter- actions with short range order correlations, while within the second shell oxygen atoms essentially exhibit liquid-like type of interactions with medium range order correlations due to localisation of transverse-like phonon packets. We show that the local order heterogeneity remains in the three phase-like equilibrium within very wide temperature range. Importantly, we highlight a catalytic role of atoms inside the nearest neighbor heterog...

Bolmatov, Dima; Gao, M; Zhernenkov, M

2014-01-01

348

Carbon dioxide consumption during soil development  

Microsoft Academic Search

Carbon is sequestered in soils by accumulation of recalcitrant organic matter and by bicarbonate weathering of silicate minerals. Carbon fixation by ecosystems helps drive weathering processes in soils and that in turn diverts carbon from annual photosynthesis-soil respiration cycling into the long-term geological carbon cycle. To quantify rates of carbon transfer during soil development in moist temperate grassland and desert

Oliver A. Chadwick; Eugene F. Kelly; Dorothy M. Merritts; Ronald G. Amundson

1994-01-01

349

Modeling the diffusion effects through the iron carbonate layer in the carbon dioxide corrosion of carbon steel  

SciTech Connect

A mechanistic model was developed for predicting carbon dioxide corrosion rates of carbon steel pipes in multiphase flow conditions. The model incorporates the chemistry, thermodynamics of carbon dioxide dissolution, multiphase mass transfer, electrochemical kinetics on the metal surface and the presence of a corrosion product film. The predicted corrosion rates show good agreement with the experimental results.

Rajappa, S.; Zhang, R.; Gopal, M. [Ohio Univ., Athens, OH (United States)

1998-12-31

350

Predator-induced reduction of freshwater carbon dioxide emissions  

NASA Astrophysics Data System (ADS)

Predators can influence the exchange of carbon dioxide between ecosystems and the atmosphere by altering ecosystem processes such as decomposition and primary production, according to food web theory. Empirical knowledge of such an effect in freshwater systems is limited, but it has been suggested that predators in odd-numbered food chains suppress freshwater carbon dioxide emissions, and predators in even-numbered food chains enhance emissions. Here, we report experiments in three-tier food chains in experimental ponds, streams and bromeliads in Canada and Costa Rica in the presence or absence of fish (Gasterosteus aculeatus) and invertebrate (Hesperoperla pacifica and Mecistogaster modesta) predators. We monitored carbon dioxide fluxes along with prey and primary producer biomass. We found substantially reduced carbon dioxide emissions in the presence of predators in all systems, despite differences in predator type, hydrology, climatic region, ecological zone and level of in situ primary production. We also observed lower amounts of prey biomass and higher amounts of algal and detrital biomass in the presence of predators. We conclude that predators have the potential to markedly influence carbon dioxide dynamics in freshwater systems.

Atwood, Trisha B.; Hammill, Edd; Greig, Hamish S.; Kratina, Pavel; Shurin, Jonathan B.; Srivastava, Diane S.; Richardson, John S.

2013-03-01

351

SCORR - supercritical carbon dioxide resist removal.  

SciTech Connect

SCORR, short for supercritical carbon dioxide resist removal, is a new technology that could continue to enable the technological development of photolithography processes in industry. SCORR is based upon the physical properties of supercritical fluids (SCFs). These special properties enable SCFs to remove coatings, residues, and particles froin high-aspect-ratio structures in integrated circuits (ICs). SCORR also eliminates rinsing and drying steps presently used in IC manufacture, thereby eliminating the generation of millions of gallons of water per fab per day. Fabricating integrated circuits relies heavily on photolithography to define the shape and pattern of individual components. Once a single stage of a silicon wafer's topography has been completed, the hardened resist must be removed. Conventional processes generates more waste than any single step in the IC manufacturing process, and the production of a complete IC can involve many photolithography iterations. The cost associated with the treatment and disposal of this waste, as well as employee health and safety considerations, are driving a search for a1 ternative, environmentally benign, cost-effective solutions. In addition, photoresist stripping is confronting finer architectures and higher aspect ratios, as well as new low-k materials that are highly sensitive to post-etch residue. Low-k dielectrics and low-resistivity conductors such as copper are necessary for meeting industry's need for faster and smaller chips. Further, each low-k choice requires different plasma-etching processes, or chemistries, to etch structures into the low-k material; therefore, the nature of the residues can be different. No one product can meet all copper/low-k applications, and existing chemistries are not tunable - or even desirable - for the new processes. We have developed a new process - known as SCORR - that removes photoresist and post-ash, -etch, and -CMP (particulate) residue from semiconductor wafers. As IC feature sizes become smaller, the need for ensuring particle removal will increase. With feature sizes of less than 0.18{micro}m, it will become imperative that all particles greater than about 0.1 micron be removed from the semiconductor wafer. Existing cleaning technologies (such as liquid or high-pressure jet scrubbing) cannot remove particles on the order of 0.1 micron because of surface boundary layer constraints. Because of the low viscosities of supercritical fluids (SCFs), these constraints are virtually eliminated.

Jacobson, G. B. (Gunilla B.); Williams, L. L. (Laurie L.); Hollis, W. K. (William K.); Barton, Jerome C.; Taylor, C. M. (Craig M.)

2002-01-01

352

Direct carbon dioxide emissions from civil aircraft  

NASA Astrophysics Data System (ADS)

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

Grote, Matt; Williams, Ian; Preston, John

2014-10-01

353

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

PubMed

Recent carbon-carbon bond forming reactions of carbon dioxide with alkenes, alkynes, dienes, aryl zinc compounds, aryl boronic esters, aryl halides, and arenes having acidic C-H bonds are reviewed in which transition-metal catalysts play an important role. PMID:22859266

Tsuji, Yasushi; Fujihara, Tetsuaki

2012-10-14

354

Water and Carbon Dioxide Adsorption at Olivine Surfaces  

SciTech Connect

Plane-wave density functional theory (DFT) calculations were performed to simulate water and carbon dioxide adsorption at the (010) surface of five olivine minerals, namely, forsterite (Mg2SiO4), calcio-olivine (Ca2SiO4), tephroite (Mn2SiO4), fayalite (Fe2SiO4), and Co-olivine (Co2SiO4). Adsorption energies per water molecule obtained from energy minimizations varied from -78 kJ mol-1 for fayalite to -128 kJ mol-1 for calcio-olivine at sub-monolayer coverage and became less exothermic as coverage increased. In contrast, carbon dioxide adsorption energies at sub-monolayer coverage ranged from -20 kJ mol-1 for fayalite to -59 kJ mol-1 for calcio-olivine. Therefore, the DFT calculations show a strong driving force for carbon dioxide displacement by water at the surface of all olivine minerals in a competitive adsorption scenario. Additionally, adsorption energies for both water and carbon dioxide were found to be more exothermic for the alkaline-earth (AE) olivines than for the transition-metal (TM) olivines and to not correlate with the solvation enthalpies of the corresponding divalent cations. However, a correlation was obtained with the charge of the surface divalent cation indicating that the more ionic character of the AE cations in the olivine structure relative to the TM cations leads to greater interactions with adsorbed water and carbon dioxide molecules at the surface and thus more exothermic adsorption energies for the AE olivines. For calcio-olivine, which exhibits the highest divalent cation charge of the five olivines, ab initio molecular dynamics simulations showed that this effect leads both water and carbon dioxide to react with the surface and form hydroxyl groups and a carbonate-like species, respectively.

Kerisit, Sebastien N.; Bylaska, Eric J.; Felmy, Andrew R.

2013-11-14

355

Carbon Dioxide Sequestration with Flue Gas Desulfurization (FGD) Gypsum  

Microsoft Academic Search

Carbonation of industrial alkaline residues can be used as a CO2 sequestration technology to reduce carbon dioxide emissions. In this study, alkaline Ca-rich flue gas desulfurization (FGD) gypsum samples were carbonated to a varying extent. These materials are cheap, available near large point sources of CO2 (power plant), and tend to react relatively rapidly with CO2 due to their chemical

Hongqi Wang; Ningning Sun; Rona J. Donahoe

2009-01-01

356

Carbonic Acid as a Reserve of Carbon Dioxide on Icy Moons: The Formation of Carbon Dioxide (CO2) in a Polar Environment  

NASA Astrophysics Data System (ADS)

Carbon dioxide (CO2) has been detected on the surface of several icy moons of Jupiter and Saturn via observation of the ?3 band with the Near-Infrared Mapping Spectrometer on board the Galileo spacecraft and the Visible-Infrared Mapping Spectrometer on board the Cassini spacecraft. Interestingly, the CO2 band for several of these moons exhibits a blueshift along with a broader profile than that seen in laboratory studies and other astrophysical environments. As such, numerous attempts have been made in order to clarify this abnormal behavior; however, it currently lacks an acceptable physical or chemical explanation. We present a rather surprising result pertaining to the synthesis of carbon dioxide in a polar environment. Here, carbonic acid was synthesized in a water (H2O)-carbon dioxide (CO2) (1:5) ice mixture exposed to ionizing radiation in the form of 5 keV electrons. The irradiated ice mixture was then annealed, producing pure carbonic acid which was then subsequently irradiated, recycling water and carbon dioxide. However, the observed carbon dioxide ?3 band matches almost exactly with that observed on Callisto; subsequent temperature program desorption studies reveal that carbon dioxide synthesized under these conditions remains in solid form until 160 K, i.e., the sublimation temperature of water. Consequently, our results suggest that carbon dioxide on Callisto as well as other icy moons is indeed complexed with water rationalizing the shift in peak frequency, broad profile, and the solid state existence on these relatively warm moons.

Jones, Brant M.; Kaiser, Ralf I.; Strazzulla, Giovanni

2014-06-01

357

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

The objective of this project is to develop a simple, inexpensive process to separate CO{sub 2} 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 water vapor. Bicarbonates are regenerated to carbonates when heated, producing a nearly pure CO{sub 2} stream after condensation of water vapor. This quarter, electrobalance tests conducted at LSU indicated that exposure of sorbent to water vapor prior to contact with carbonation gas does not significantly increase the reaction rate. Calcined fine mesh trona has a greater initial carbonation rate than calcined sodium bicarbonate, but appears to be more susceptible to loss of reactivity under severe calcination conditions. The Davison attrition indices for Grade 5 sodium bicarbonate, commercial grade sodium carbonate and extra fine granular potassium carbonate were, as tested, outside of the range suitable for entrained bed reactor testing. Fluidized bed testing at RTI indicated that in the initial stages of reaction potassium carbonate removed 35% of the carbon dioxide in simulated flue gas, and is reactive at higher temperatures than sodium carbonate. Removals declined to 6% when 54% of the capacity of the sorbent was exhausted. Carbonation data from electrobalance testing was correlated using a shrinking core reaction model. The activation energy of the reaction of sodium carbonate with carbon dioxide and water vapor was determined from nonisothermal thermogravimetry.

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

2002-04-01

358

Helium enrichment during convective carbon dioxide dissolution  

NASA Astrophysics Data System (ADS)

Motivated by observed variations of the CO2/He ratios in natural carbon dioxide (CO2) reservoirs, such as the Bravo Dome field in northeastern New Mexico, we have performed laboratory experiments equilibrating gas mixtures containing Helium (He) and CO2 with water, at close to ambient conditions in a closed system. The experimental design allows for continuous measurement of headspace pressure as well as timed interval measurements of the CO2/He ratios and the ?13C value of CO2 in the headspace. Results from three dissolution experiments are reported: 1) pure Helium system, 2) 98% CO2 + 2% Nitrogen system, and 3) 97% CO2 and 3% Helium. Final equilibrated experimental results are compared to theoretical results obtained using Henry's Law relationships. The evolution of the amount of dissolved CO2 computed from gas pressure and gas compositions are in good agreement with Henry's Law relationships. For example, the CO2 + N2 system was initially pressurized with pure CO2 to 1323 mbar and after six days it equilibrated to a measured headspace pressure of 596 mbar. This compares very well with a calculated equilibrium headspace pressure of 592 mbar for this system. The CO2 + He system was pressurized to 1398 mbar CO2 and after six days equilibrated to a measured headspace pressure of 397 mbar. This measured pressure is slightly higher than the predicted equilibrated headspace pressure of 341 mbar, indicating a possible leak in the system during this particular experiment. In both experiments the initial pH of the water was 9.3 and the final equilibrated pH was 5.4. The ?13C value of equilibrated headspace CO2 was within 0.25‰ of its starting ?13C value, demonstrating insignificant carbon isotope fractionation at low pH. Measured Helium/ CO2 ratios throughout the CO2+Helium experiment preserve a non-linear trend of increasing He/ CO2 ratios through time that correlate very well with the measured pressure drop from CO2 dissolution. This indicates that gas composition, in particular the He/ CO2-ratio, can be used to infer the amount of dissolved CO2 in the field where pressure evolution is not available. Our experiments show that the rate of dissolution is determined by convective mass transfer in the brine. Convective transport is driven by the increase of water density with increasing CO2 saturation. However, unlike previous experiments with analog systems we do not observe a constant dissolution rate. This is due to the continued drop in gas pressure that continuously reduces the equilibrium aqueous CO2 concentration and with it the driving force for convection. This feed back may significantly reduce the magnitude of solubility trapping that can be expected during geological CO2 storage.

Larson, T.; Hesse, M. A.

2013-12-01

359

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.

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

2001-01-01

360

Carbon Dioxide Capture from Flue Gas Using Dry, Regenerable Sorbents  

SciTech Connect

This report describes research conducted between July 1, 2006 and September 30, 2006 on the use of dry regenerable sorbents for removal of carbon dioxide (CO{sub 2}) from coal combustion flue gas. Modifications to the integrated absorber/ sorbent regenerator/ sorbent cooler system were made to improve sorbent flow consistency and measurement reliability. Operation of the screw conveyor regenerator to achieve a sorbent temperature of at least 120 C at the regenerator outlet is necessary for satisfactory carbon dioxide capture efficiencies in succeeding absorption cycles. Carbon dioxide capture economics in new power plants can be improved by incorporating increased capacity boilers, efficient flue gas desulfurization systems and provisions for withdrawal of sorbent regeneration steam in the design.

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

2006-09-30

361

CARBON DIOXIDE SEPARATION BY PHASE ENHANCED GAS-LIQUID ABSORPTION  

SciTech Connect

A new process called phase enhanced gas-liquid absorption has been developed in its early stage. It was found that adding another phase into the absorption system of gas/aqueous phase could enhance the absorption rate. A system with three phases was studied. In the system, gas phase was carbon dioxide. Two liquid phases were used. One was organic phase. Another was aqueous phase. By addition of organic phase into the absorption system of CO{sub 2}-aqueous phase, the absorption rate of CO{sub 2} was increased significantly. CO{sub 2} finally accumulated into aqueous phase. The experimental results proved that (1) Absorption rate of carbon dioxide was enhanced by adding organic phase into gas aqueous phase system; (2) Organic phase played the role of transportation of gas solute (CO{sub 2}). Carbon dioxide finally accumulated into aqueous phase.

Liang Hu

2004-09-30

362

CARBON DIOXIDE SEPARATION BY PHASE ENHANCED GAS-LIQUID ABSORPTION  

SciTech Connect

A new process called phase enhanced gas-liquid absorption has been developed in its early stage. It was found that adding another phase into the absorption system of gas/aqueous phase could enhance the absorption rate. A system with three phases was studied. In the system, gas phase was carbon dioxide. Two liquid phases were used. One was organic phase. Another was aqueous phase. By addition of organic phase into the absorption system of CO{sub 2}-aqueous phase, the absorption rate of CO{sub 2} was increased significantly. CO{sub 2} finally accumulated into aqueous phase. The experimental results proved that (1) Absorption rate of carbon dioxide was enhanced by adding organic phase into gas aqueous phase system; (2) Organic phase played the role of transportation of gas solute (CO{sub 2}). Carbon dioxide finally accumulated into aqueous phase.

Liang Hu; Adeyinka A. Adeyiga

2004-05-01

363

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

PubMed

The case is presented of a 71 year-old male, diagnosed with a thymoma. A thoracoscopic thymectomy was performed using the carbon dioxide insufflation technique in the mediastinum. During the procedure, while performing one-lung ventilation, the patient's respiration worsened. The contralateral lung had collapsed, as carbon dioxide was travelling from the mediastinum to the thorax through the opened pleura. Two-lung ventilation was decided upon, which clearly improved oxygenation in the arterial gases and airway pressures. Both pH and pCO2 stabilized. The surgical approach and the carbon dioxide technique were continued because 2-lung ventilation did not affect the surgical procedure. This technique has many serious complications and it should always be performed using 2-lung ventilation. PMID:24952826

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

2015-02-01

364

BOREAS TGB-12 Isotropic Carbon Dioxide Data over the NSA  

NASA Technical Reports Server (NTRS)

The BOREAS TGB-12 team made measurements of soil carbon inventories, carbon concentration in soil gases, and rates of soil respiration at several sites to estimate the rates of carbon accumulation and turnover in each of the major vegetation types. This data set contains information on the carbon isotopic content of carbon dioxide sampled from soils in the NSA-OBS, NSA-YJP, and NSA-OJP sites. Data were collected from 14-Nov-1993 to 10-Oct-1996. The data are stored in tabular ASCII files.

Trumbore, Susan; Hall, Forrest G. (Editor); Sundquist, Eric; Winston, Greg; Conrad, Sara K. (Editor)

2000-01-01

365

49 CFR 195.8 - Transportation of hazardous liquid or carbon dioxide in pipelines constructed with other than...  

Code of Federal Regulations, 2014 CFR

... Transportation of hazardous liquid or carbon dioxide in pipelines constructed with... Transportation of hazardous liquid or carbon dioxide in pipelines constructed with...person may transport any hazardous liquid or carbon dioxide through a pipe that is...

2014-10-01

366

Regulation of Carbonic Anhydrase Expression by Zinc, Cobalt, and Carbon Dioxide in the Marine Diatom  

E-print Network

Regulation of Carbonic Anhydrase Expression by Zinc, Cobalt, and Carbon Dioxide in the Marine of carbonic anhydrase (CA) in the marine diatom Thalassiosira weissflogii. We have examined the roles components: a mechanism for directly or indirectly taking up HCO3 and at least one carbonic anhydrase (CA

Morel, François M. M.

367

Entrapment of Carbon Dioxide in the Active Site of Carbonic Anhydrase II*  

E-print Network

Entrapment of Carbon Dioxide in the Active Site of Carbonic Anhydrase II* Received for publication step of CO2 hydration catalyzed by the zinc- metalloenzyme human carbonic anhydrase II, the binding substrates and revealing hydrophobic pockets in proteins. Since their discovery (2), the carbonic anhydrases

Gruner, Sol M.

368

Fate of fossil fuel carbon dioxide and the global carbon budget  

Microsoft Academic Search

The fate of fossil fuel carbon dioxide released into the atmosphere depends on the exchange rates of carbon between the atmosphere and three major carbon reservoirs, namely, the oceans, shallow-water sediments, and the terrestrial biosphere. Various assumptions and models used to estimate the global carbon budget for the last 20 years are reviewed and evaluated. Several versions of recent atmosphere-ocean

W. S. Broecker; T. Takahashi; H. J. Simpson; T.-H. Peng

1979-01-01

369

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

ERIC Educational Resources Information Center

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

Miyauchi, Takuya; Kamata, Masahiro

2012-01-01

370

Multiline short-pulse solid-state seeded carbon dioxide laser for extreme ultraviolet employing multipass radio frequency excited slab amplifier.  

PubMed

In this Letter we describe in more detail a solid-state seeded, nanosecond pulse, multiline CO(2) oscillator designed and built for the extreme ultraviolet (EUV) laser-produced-plasma (LPP) source. Our oscillator featured quantum cascade laser seeders, a diffraction-type seed beam combiner, and a radio-frequency-discharge-excited, diffusion-cooled, slab-waveguide CO(2) gain cell in a compact multipass regenerative amplifier configuration. The oscillator generated pulses of exceptional stability in terms of envelope, energy, and spectrum. Excellent stability of output was achieved without any additional techniques. The output spectrum consisted of two laser lines of a 00(0)1-10(0)0 band of a CO(2) molecule, P20 and P22, with a target of four lines P18-P24. The pulse duration was electronically adjustable between 11 and 35 ns at a repetition frequency from a few hertz to hundreds of kilohertz. Electronic adjustment of the pulse duration was achieved by relative timing offsets of individual seeders, opening an avenue to a range of on-line adjustments of pulse shape and spectral content timing. The jitter-tolerant operation allows for easy synchronization with an external event, such as a droplet target in an EUV LPP source. A resistance to parasitic seeding of more than 40 dB was recorded. The oscillator produced up to 20 W of average output power at a repetition rate of 100 kHz in a near-diffraction-limited beam of M(2)<1.3 and a pointing stability below 50 ?rad. PMID:23503247

Nowak, Krzysztof M; Ohta, Takeshi; Suganuma, Takashi; Fujimoto, Junichi; Mizoguchi, Hakaru

2013-03-15

371

Climate Policy Design: Interactions among Carbon Dioxide, Methane, and Urban Air Pollution Constraints  

E-print Network

Climate Policy Design: Interactions among Carbon Dioxide, Methane, and Urban Air Pollution Policy Design: Interactions among Carbon Dioxide, Methane, and Urban Air Pollution Constraints by Marcus. The third case examines the benefits of increased policy coordination between air pollution constraints

de Weck, Olivier L.

372

Carbon Dioxide Capture from Coal-Fired Power Plants: A Real Options Analysis Ram Chandra Sekar  

E-print Network

Carbon Dioxide Capture from Coal-Fired Power Plants: A Real Options Analysis by Ram Chandra Sekar;2 #12;3 Carbon Dioxide Capture in Coal-Fired Power Plants: A Real Options Analysis by Ram Chandra Sekar

373

Laser Direct Writing of Hydrous Ruthenium Dioxide Micro-Pseudocapacitors Craig B. Arnold1  

E-print Network

Laser Direct Writing of Hydrous Ruthenium Dioxide Micro-Pseudocapacitors Craig B. Arnold1 , Ryan C. ABSTRACT We are using a laser engineering approach to develop and optimize hydrous ruthenium dioxide (Ru The manufacture of thin film hydrous ruthenium dioxide pseudocapacitors is generally considered difficult due

Arnold, Craig B.

374

Carbon dioxide sequestration by aqueous mineral carbonation of magnesium silicate minerals  

SciTech Connect

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 in the concentration of atmospheric carbon dioxide. By accelerating the naturally occurring carbonation of magnesium silicate minerals it is possible to sequester carbon dioxide in the geologically stable mineral magnesite (MgCO3). The carbonation of two classes of magnesium silicate minerals, olivine (Mg2SiO4) and serpentine (Mg3Si2O5(OH)4), was investigated in an aqueous process. The slow natural geologic process that converts both of these minerals to magnesite can be accelerated by increasing the surface area, increasing the activity of carbon dioxide in the solution, introducing imperfections into the crystal lattice by high-energy attrition grinding, and in the case of serpentine, by thermally activating the mineral by removing the chemically bound water. The effect of temperature is complex because it affects both the solubility of carbon dioxide and the rate of mineral dissolution in opposing fashions. Thus an optimum temperature for carbonation of olivine is approximately 185 degrees C and 155 degrees C for serpentine. This paper will elucidate the interaction of these variables and use kinetic studies to propose a process for the sequestration of the carbon dioxide.

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

2003-01-01

375

Reduction of soil carbon formation by tropospheric ozone under increased carbon dioxide levels.  

PubMed

In the Northern Hemisphere, ozone levels in the troposphere have increased by 35 per cent over the past century, with detrimental impacts on forest and agricultural productivity, even when forest productivity has been stimulated by increased carbon dioxide levels. In addition to reducing productivity, increased tropospheric ozone levels could alter terrestrial carbon cycling by lowering the quantity and quality of carbon inputs to soils. However, the influence of elevated ozone levels on soil carbon formation and decomposition are unknown. Here we examine the effects of elevated ozone levels on the formation rates of total and decay-resistant acid-insoluble soil carbon under conditions of elevated carbon dioxide levels in experimental aspen (Populus tremuloides) stands and mixed aspen-birch (Betula papyrifera) stands. With ambient concentrations of ozone and carbon dioxide both raised by 50 per cent, we find that the formation rates of total and acid-insoluble soil carbon are reduced by 50 per cent relative to the amounts entering the soil when the forests were exposed to increased carbon dioxide alone. Our results suggest that, in a world with elevated atmospheric carbon dioxide concentrations, global-scale reductions in plant productivity due to elevated ozone levels will also lower soil carbon formation rates significantly. PMID:14562100

Loya, Wendy M; Pregitzer, Kurt S; Karberg, Noah J; King, John S; Giardina, Christian P

2003-10-16

376

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

SciTech Connect

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

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

1986-01-01

377

REDUCING THE UNCERTAINTY OF NORTH AMERICAN CARBON FLUX ESTIMATES USING AN EXTENDED ATMOSPHERIC CARBON DIOXIDE MEASUREMENT NETWORK.  

E-print Network

??We evaluate North American carbon fluxes using a monthly global Bayesian synthesis inversion that includes well-calibrated carbon dioxide concentrations measured at continental flux towers. We… (more)

Butler, Martha

2010-01-01

378

Numerically Simulating Carbonate Mineralization of Basalt with Injection of Carbon Dioxide into Deep Saline Formations  

SciTech Connect

The principal mechanisms for the geologic sequestration of carbon dioxide in deep saline formations include geological structural trapping, hydrological entrapment of nonwetting fluids, aqueous phase dissolution and ionization, and geochemical sorption and mineralization. In sedimentary saline formations the dominant mechanisms are structural and dissolution trapping, with moderate to weak contributions from hydrological and geochemical trapping; where, hydrological trapping occurs during the imbibition of aqueous solution into pore spaces occupied by gaseous carbon dioxide, and geochemical trapping is controlled by generally slow reaction kinetics. In addition to being globally abundant and vast, deep basaltic lava formations offer mineralization kinetics that make geochemical trapping a dominate mechanism for trapping carbon dioxide in these formations. For several decades the United States Department of Energy has been investigating Columbia River basalt in the Pacific Northwest as part of its environmental programs and options for natural gas storage. Recently this nonpotable and extensively characterized basalt formation is being reconsidered as a potential reservoir for geologic sequestration of carbon dioxide. The reservoir has an estimated storage capacity of 100 giga tonnes of carbon dioxide and comprises layered basalt flows with sublayering that generally alternates between low permeability massive and high permeability breccia. Chemical analysis of the formation shows 10 wt% Fe, primarily in the +2 valence. The mineralization reaction that makes basalt formations attractive for carbon dioxide sequestration is that of calcium, magnesium, and iron silicates reacting with dissolved carbon dioxide, producing carbonate minerals and amorphous quartz. Preliminary estimates of the kinetics of the silicate-to-carbonate reactions have been determined experimentally and this research is continuing to determine effects of temperature, pressure, rock composition and mineral assemblages on the reaction rates. This study numerically investigates the injection, migration and sequestration of supercritical carbon dioxide in deep Columbia River basalt formations using the multifluid subsurface flow and reactive transport simulator STOMP-CO2 with its ECKEChem module. Simulations are executed on high resolution multiple stochastic realizations of the layered basalt systems and demonstrate the migration behavior through layered basalt formations and the mineralization of dissolved carbon dioxide. Reported results include images of the migration behavior, distribution of carbonate formation, quantities of injected and sequestered carbon dioxide, and percentages of the carbon dioxide sequestered by different mechanisms over time.

White, Mark D.; McGrail, B. Peter; Schaef, Herbert T.; Bacon, Diana H.

2006-07-08

379

Continual production of glycerol from carbon dioxide by Dunaliella tertiolecta.  

PubMed

Microalgae have high photosynthetic efficiencies and produce many valuable compounds from carbon dioxide. The Dunaliella genus accumulates glycerol, yet no commercial process currently exists for glycerol production from this microalga. Here it was found that in addition to intracellular accumulation, Dunaliella tertiolecta also releases glycerol into the external medium continuously, forming a large and stable carbon pool. The process is not affected by nutrient starvation or onset of cell death. Carbon dioxide was fixed at a constant rate, the bulk of it being channelled to extracellular glycerol (82%), resulting in enhanced photosynthetic carbon assimilation of 5 times that used for biomass production. The final extracellular glycerol concentration was 34 times the maximum concentration of intracellular glycerol; the latter declined further during cell death. Findings from this work will assist in the development of a bioconversion process to produce glycerol using D. tertiolecta without the need for cell harvest or disruption. PMID:23567730

Chow, Yvonne Y S; Goh, Serena J M; Su, Ziheng; Ng, Daphne H P; Lim, Chan Yuen; Lim, Natalie Y N; Lin, Huixin; Fang, Lei; Lee, Yuan Kun

2013-05-01

380

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

Electrobalance studies of calcination and carbonation of sodium bicarbonate materials were conducted at Louisiana State University. Calcination in an inert atmosphere was rapid and complete at 120 C. Carbonation was temperature dependent, and both the initial rate and the extent of reaction were found to decrease as temperature was increased between 60 and 80 C. A fluidization test apparatus was constructed at RTI and two sodium bicarbonate materials were fluidized in dry nitrogen at 22 C. The bed was completely fluidized at between 9 and 11 in. of water pressure drop. Kinetic rate expression derivations and thermodynamic calculations were conducted at RTI. Based on literature data, a simple reaction rate expression, which is zero order in carbon dioxide and water, was found to provide the best fit against reciprocal temperature. Simulations based on process thermodynamics suggested that approximately 26 percent of the carbon dioxide in flue gas could be recovered using waste heat available at 240 C.

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

2001-05-01

381

Heterogeneous saline formations for carbon dioxide disposal: Impact of varying heterogeneity on containment and trapping  

Microsoft Academic Search

Natural gas fields often contain carbon dioxide in their reservoir fluids. Exploitation of these resources requires the removal of carbon dioxide from produced fluids to meet quality standards for sale into a domestic market or for the processing of the gas into LNG. To limit the atmospheric emissions of carbon dioxide, a major greenhouse gas, it has been proposed that

Matthew Flett; Randal Gurton; Geoff Weir

2007-01-01

382

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

E-print Network

A correlation of optimal heat rejection pressures in transcritical carbon dioxide cycles S.M. Liaoa) 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

Zhao, Tianshou

383

Exergy analysis of transcritical carbon dioxide refrigeration cycle with an expander  

E-print Network

Exergy analysis of transcritical carbon dioxide refrigeration cycle with an expander Jun Lan Yang is performed for the transcritical carbon dioxide refrigeration cycles with a throttling valve compression cycle is applicable for carbon dioxide for water heating and comfort cooling and heating [4

Bahrami, Majid

384

46 CFR 35.40-7 - Carbon dioxide alarm-T/ALL.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Carbon dioxide alarm-T/ALL. 35.40-7 Section 35.40-7 Shipping...OPERATIONS Posting and Marking Requirements-TB/ALL. § 35.40-7 Carbon dioxide alarm—T/ALL. Adjacent to all carbon dioxide fire...

2010-10-01

385

Carbon Dioxide Footprint of the Northwest Power System Comments submitted by Grant County Public Utility District  

E-print Network

Carbon Dioxide Footprint of the Northwest Power System Comments submitted by Grant County Public paper: Carbon Dioxide Footprint of the Northwest Power System, dated September 13, 2007. The Grant done a very thorough job of assessing the current and future carbon dioxide footprints of the Northwest

386

Carbon dioxide fluxes over bermudagrass, native prairie, and sorghum  

Microsoft Academic Search

The Bowen ratio\\/energy balance (BREB) method was used to measure 30min water vapor and carbon dioxide (CO2) fluxes over three fields dominated by different C4 grasses (bermudagrass, tallgrass native prairie, and sorghum) at the Blackland Research Center, Temple, TX. Fluxes were related to biotic and abiotic phenomena. Carbon accumulation rates calculated from BREB measurements were compared with those determined from

W. A Dugas; M. L Heuer; H. S Mayeux

1999-01-01

387

Carbon Dioxide Capture from Flue Gas Using Dry Regenerable Sorbents  

Microsoft Academic Search

Regenerable sorbents based on sodium carbonate (NaCO) can be used to separate carbon dioxide (CO) from coal-fired power plant flue gas. Upon thermal regeneration and condensation of water vapor, CO is released in a concentrated form that is suitable for reuse or sequestration. During the research project described in this report, the technical feasibility and economic viability of a thermal-swing

Thomas Nelson; David Green; Paul Box; Raghubir Gupta; Gennar Henningsen

2007-01-01

388

Carbon Dioxide Capture from Flue Gas Using Dry, Regenerable Sorbents  

SciTech Connect

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

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

2006-03-31

389

Insensitivity of global warming potentials to carbon dioxide emission scenarios  

Microsoft Academic Search

GLOBAL warming potentials for radiatively active trace gases (such as methane and chlorofluorocarbons) have generally been expressed1-2 relative to the time-integrated climate forcing per unit emission of carbon dioxide. Previous attempts to estimate the integrated climate forcing per unit CO2 emitted have focused on perturbations to steady-state conditions in carbon-cycle models. But for non-steady-state conditions, the integrated climate forcing from

Ken Caldeira; James F. Kasting

1993-01-01

390

Photodissociation of carbon dioxide in the Mars upper atmosphere  

NASA Technical Reports Server (NTRS)

Calculation of the intensity of two of the emissions produced during the dissociative excitation of carbon dioxide in the upper atmosphere of Mars by solar ultraviolet radiation. The calculation tangential column emission rates of the atomic oxygen 2972-A line and the carbon monoxide Cameron bands produced by the photodissociative mechanism are found to be factors of 3 and 10, respectively, smaller than the emission rates observed by Mariner ultraviolet spectrometers.

Barth, C. A.

1974-01-01

391

Potential carbon dioxide fixation by industrially important microalgae  

Microsoft Academic Search

The present study aimed at investigating the carbon metabolism in terms of carbon dioxide fixation and its destination in microalgae cultivations. To this purpose, analysis of growth parameters, media of cultivation, biomass composition and productivity and nutrients balance were performed. Four microalgae suitable for mass cultivation were evaluated: Dunaliella tertiolecta SAD-13.86, Chlorella vulgaris LEB-104, Spirulina platensis LEB-52 and Botryococcus braunii

Eduardo Bittencourt Sydney; Wilerson Sturm; Julio Cesar de Carvalho; Vanete Thomaz-Soccol; Christian Larroche; Ashok Pandey; Carlos Ricardo Soccol

2010-01-01

392

Geology of Bravo Dome carbon dioxide gas field, New Mexico  

Microsoft Academic Search

The Bravo Dome carbon dioxide gas field is located in Union and Harding Counties of northeast New Mexico. The Bravo Dome field covers approximately 800,000 acres, but areal boundaries of the field have not been fully defined. Production in 1989 was 113 bcf of gas from 272 wells. Cumulative production at the end of 1989 was 626 bcf. Estimated recoverable

1991-01-01

393

Extended-length fiber optic carbon dioxide monitoring  

NASA Astrophysics Data System (ADS)

This paper discusses the design and performance of fiber optic distributed intrinsic sensors for dissolved carbon dioxide, based on the use optical fibers fabricated so that their entire lengths are chemically sensitive. These fibers use a polymer-clad, silica-core structure where the cladding undergoes a large, reversible, change in optical absorbance in the presence of CO2. The local "cladding loss" induced by this change is thus a direct indication of the carbon dioxide concentration in any section of the fiber. To create these fibers, have developed a carbon dioxide-permeable polymer material that adheres well to glass, is physically robust, has a refractive index lower than fused silica, and acts as excellent hosts for a unique colorimetric indicator system that respond to CO2. We have used this proprietary material to produce carbon-dioxide sensitive fibers up to 50 meters long, using commercial optical fiber fabrication techniques. The sensors have shown a measurement range of dissolved CO2 of 0 to 1,450 mg/l (0 to 100% CO2 saturation), limit of detection of 0.3 mg/l and precision of 1.0 mg/l in the 0 to 50 mg/l dissolved CO2 range, when a 5 meter-long sensor fiber segment is used. Maximum fiber length, minimum detectable concentration, and spatial resolution can be adjusted by adjusting indicator concentration and fiber design.

Delgado-Alonso, Jesus; Lieberman, Robert A.

2013-05-01

394

Molecular simulations of carbon dioxide and water: cation solvation.  

PubMed

Proposed carbon dioxide sequestration scenarios in sedimentary reservoirs require investigation into the interactions between supercritical carbon dioxide, brines, and the mineral phases found in the basin and overlying caprock. Molecular simulations can help to understand the partitioning of metal cations between aqueous solutions and supercritical carbon dioxide where limited experimental data exist. In this effort, we used classical molecular dynamics simulations to compare the solvation of alkali and alkaline-earth metal cations in water and liquid CO(2) at 300 K by combining a flexible simple point charge model for water and an accurate flexible force field for CO(2). Solvation energies for these cations are larger in water than in carbon dioxide, suggesting that they will partition preferentially into water. In both aqueous and CO(2) solutions, the solvation energies decrease with cation size and increase with cation charge. However, changes in solvation energy with ionic radii are smaller in CO(2) than in water suggesting that the partitioning of cations into CO(2) will increase with ion size. Simulations of the interface between aqueous solution and supercritical CO(2) support this suggestion in that some large cations (e.g., Cs(+) and K(+)) partition into the CO(2) phase, often with a partial solvation sphere of water molecules. PMID:22779448

Criscenti, Louise J; Cygan, Randall T

2013-01-01

395

Counter-current carbon dioxide extraction of soy skim  

Technology Transfer Automated Retrieval System (TEKTRAN)

The use of carbon dioxide in a counter-current fractionation column was investigated as a means to remove residual fat from soy skim after enzyme-assisted aqueous extraction of soybeans. The stainless steel column was 1.2 meters long with an internal diameter of 1.75 cm and filled protruded stainles...

396

The Subsurface Fluid Mechanics of Geologic Carbon Dioxide Storage  

E-print Network

The Subsurface Fluid Mechanics of Geologic Carbon Dioxide Storage by Michael Lawrence Szulczewski S the fluid mechanics of CO2 storage, with the goal of informing two practical questions. The first question by . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Heidi M. Nepf Chair, Departmental Committee for Graduate Students #12;2 #12;The Subsurface Fluid

397

Carbon Dioxide Production and Sodium Transport by the Toad Bladder  

Microsoft Academic Search

IN order to investigate further the relationship of cellular metabolism to active ion transport, we have correlated carbon dioxide production with sodium transport by the urinary bladder of the toad, Bufo marinus, in vitro. The toad bladder was mounted so as to separate the two halves of a glass chamber, and each side was bathed with a phosphate Ringer's solution

Roy H. Maffly; Cecil H. Coggins

1965-01-01

398

Climate change and carbon dioxide storage Herbert E. Huppert  

E-print Network

1 Climate change and carbon dioxide storage Herbert E. Huppert Institute of Theoretical, spread material in a roughly symmetric fashion. Particulate matter, or planetesmials, came on Earth having been found in Australia. Of course the Earth has changed dramatically over these four

Huppert, Herbert

399

The Concentration of Atmospheric Carbon Dioxide in Hawaii  

Microsoft Academic Search

The concentration of atmospheric carbon dioxide at and near Mauna Loa Ob- servatory, Hawaii, is reported for the first six years (1958-1963) of a long-term program to document the effects of the combustion of coal and petroleum on the distribution of COs gas in the atmosphere and in the world's oceans. The majority of the measurements reported here were obtained

Jack C. Pales; Charles D. Keeling

1965-01-01

400

Global Warming: Carbon Dioxide and the Greenhouse Effect  

NSDL National Science Digital Library

This video segment demonstrates carbon dioxide's role in the greenhouse effect and explains how increasing concentrations of C02 in the atmosphere may be contributing to global warming. Video includes an unusual demonstration of C02's heat-absorbing properties, using infrared film, a researcher's face, and a stream of C02 between them.

FRONTLINE/NOVA

401

The role of carbon dioxide in ammonia emission from manure  

Technology Transfer Automated Retrieval System (TEKTRAN)

Ammonia emission from manure is a significant loss of fixed N from agricultural systems, and contributes to air pollution and ecosystem degradation. Despite the development of numerous mathematical models for predicting ammonia emission, the interactions between carbon dioxide emission, manure pH, a...

402

Carbon dioxide supersaturation in the surface waters of lakes  

Microsoft Academic Search

Data on the partial pressure of carbon dioxide (COâ) in the surface waters from a large number of lakes (1835) with a worldwide distribution show that only a small proportion of the 4665 samples analyzed (less than 10 percent) were within {+-}20 percent of equilibrium with the atmosphere and that most samples (87 percent) were supersaturated. The mean partial pressure

J. J. Cole; N. F. Caraco; G. W. Kling; T. K. Kratz

1994-01-01

403

Using the 5E Learning Cycle Sequence with Carbon Dioxide  

ERIC Educational Resources Information Center

The authors used the 5E learning cycle (engage, explore, explain, extend, and evaluate) and a pulmonary carbon dioxide mystery to introduce eighth grade students to the study of chemistry. The activity engages students in measurement, data collection, data analysis, media and internet research, research design, and report writing as they search…

Schlenker, Richard M.; Blanke, Regina; Mecca, Peter

2007-01-01

404

40 CFR 86.1524 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2012 CFR

...Petroleum Gas-Fueled Diesel-Cycle Heavy-Duty Engines, New Otto-Cycle Light-Duty Trucks, and New...Petroleum Gas-Fueled Diesel-Cycle Light-Duty Trucks; Idle Test Procedures § 86.1524 Carbon dioxide analyzer...

2012-07-01

405

40 CFR 86.1524 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2010 CFR

...Petroleum Gas-Fueled Diesel-Cycle Heavy-Duty Engines, New Otto-Cycle Light-Duty Trucks, and New...Petroleum Gas-Fueled Diesel-Cycle Light-Duty Trucks; Idle Test Procedures § 86.1524 Carbon dioxide analyzer...

2010-07-01

406

40 CFR 86.1524 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2013 CFR

...Petroleum Gas-Fueled Diesel-Cycle Heavy-Duty Engines, New Otto-Cycle Light-Duty Trucks, and New...Petroleum Gas-Fueled Diesel-Cycle Light-Duty Trucks; Idle Test Procedures § 86.1524 Carbon dioxide analyzer...

2013-07-01

407

40 CFR 86.1524 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2011 CFR

...Petroleum Gas-Fueled Diesel-Cycle Heavy-Duty Engines, New Otto-Cycle Light-Duty Trucks, and New...Petroleum Gas-Fueled Diesel-Cycle Light-Duty Trucks; Idle Test Procedures § 86.1524 Carbon dioxide analyzer...

2011-07-01

408

40 CFR 86.1524 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2014 CFR

...Petroleum Gas-Fueled Diesel-Cycle Heavy-Duty Engines, New Otto-Cycle Light-Duty Trucks, and New...Petroleum Gas-Fueled Diesel-Cycle Light-Duty Trucks; Idle Test Procedures § 86.1524 Carbon dioxide analyzer...

2014-07-01

409

Carbon dioxide flash-freezing applied to ice cream production  

E-print Network

(cont.) Carbon dioxide is recompressed from 1.97 x 106 Pa (285 psi) to 3.96 x 106 Pa (575 psi). The process is scaled by increasing the number of nozzles to accommodate the desired flow rate. Only 165 nozzles are required ...

Peters, Teresa Baker, 1981-

2006-01-01

410

27 CFR 24.319 - Carbon dioxide record.  

Code of Federal Regulations, 2013 CFR

A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted to establish compliance with the limitations prescribed in § 24.245. (Sec. 201, Pub. L. 85-859, 72 Stat. 1381, as amended (26 U.S.C....

2013-04-01

411

46 CFR 196.37-9 - Carbon dioxide alarm.  

Code of Federal Regulations, 2010 CFR

46 ? Shipping ? 7 ? 2010-10-01 ? 2010-10-01 ? false ? Carbon dioxide alarm. ? 196.37-9 ? Section 196.37-9 ? Shipping ? COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ? OCEANOGRAPHIC RESEARCH VESSELS ? OPERATIONS ? Markings for Fire and Emergency Equipment, etc. ? § 196.37-9 ?...

2010-10-01

412

46 CFR 196.37-9 - Carbon dioxide alarm.  

Code of Federal Regulations, 2011 CFR

46 ? Shipping ? 7 ? 2011-10-01 ? 2011-10-01 ? false ? Carbon dioxide alarm. ? 196.37-9 ? Section 196.37-9 ? Shipping ? COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ? OCEANOGRAPHIC RESEARCH VESSELS ? OPERATIONS ? Markings for Fire and Emergency Equipment, etc. ? § 196.37-9 ?...

2011-10-01

413

40 CFR 86.224-94 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2012 CFR

Emission Regulations for 1994 and Later Model Year Gasoline-Fueled New Light-Duty Vehicles, New Light-Duty Trucks and New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.224-94 Carbon dioxide analyzer calibration. The provisions of §...

2012-07-01

414

Modeling Seasonality in Carbon Dioxide Emissions From Fossil Fuel Consumption  

Microsoft Academic Search

Using United States data, a method is developed to estimate the monthly consumption of solid, liquid and gaseous fossil fuels using monthly sales data to estimate the relative monthly proportions of the total annual national fossil fuel use. These proportions are then used to estimate the total monthly carbon dioxide emissions for each state. From these data, the goal is

P. Kishore; K. Igarashi; H. Oikawa; M. Uotome; J. S. Gregg; R. J. Andres

2004-01-01

415

Corrosion of various engineering alloys in supercritical carbon dioxide  

E-print Network

The corrosion resistance of ten engineering alloys were tested in a supercritical carbon dioxide (S-CO 2) environment for up to 3000 hours at 610°C and 20MPa. The purpose of this work was to evaluate each alloy as a potential ...

Gibbs, Jonathan Paul

2010-01-01

416

Elevated Carbon Dioxide and Ozone Concentrations Alter Soybean Antioxidant Metabolism  

Technology Transfer Automated Retrieval System (TEKTRAN)

One important mechanism by which plants sense and respond to their environment is through redox control. Oxidative damage at the cellular level can feed forward to decrease leaf photosynthesis and therefore canopy and ecosystem productivity. How rising atmospheric carbon dioxide (CO2) and tropospher...

417

How Can We Use Carbon Dioxide as a Solvent?  

ERIC Educational Resources Information Center

This article describes the work being undertaken to make more use of supercritical carbon dioxide as a green solvent. It discusses how the use of surfactants can address the limitations of supercritical CO[subscript 2] in dissolving solutes that are polar and of higher molecular weight. The design of appropriate hydrocarbon CO[subscript 2]-philic…

Mohamed, Azmi; Eastoe, Julian

2011-01-01

418

Classroom Carbon Dioxide Concentration, School Attendance, and Educational Attainment  

ERIC Educational Resources Information Center

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

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

2014-01-01

419

Environmental Challenges: Radon and Carbon Dioxide in School Buildings.  

ERIC Educational Resources Information Center

Many school buildings with high radon levels also exhibit high carbon dioxide levels that starve the minds of students for oxygen. Administrators must realize that the world's best educator cannot teach minds made dysfunctional by their environment. This article describes Environmental Protection Agency testing results and offers radon monitoring…

Krueger, James

1991-01-01

420

Biodiversity and biological impact of ocean disposal of carbon dioxide  

SciTech Connect

Five major characteristics of deep-sea organisms that are relevant to the carbon dioxide ocean sequestration are pointed out. They are (1) low biological activities, (2) long life span, (3) high sensitivity to the environmental disturbance, (4) high species diversity, and (5) low density. These characteristics suggest the deep-sea species are sensitive to the environmental disturbance, and once they are damaged, they may easily become extinct or it might take a long time to recover. To get public acceptance for ocean sequestration of carbon dioxide, the authors need a reliable assessment of its affects on the deep-sea ecosystem based on an accurate model. For a better modeling, data regarding the long-term (chronic) effect of slightly increased concentration of carbon dioxide on the deep-sea organisms are prerequisite. Precise data regarding such biological characteristics can be obtained only from in-situ experiments. To develop a system for ecophysiological in-situ experiments of deep-sea organisms is thus as important as solving the technological problems related to the ocean sequestration of carbon dioxide.

Shirayama, Yoshihisa [Univ. of Tokyo (Japan)] [Univ. of Tokyo (Japan)

1998-07-01

421

2008 Nature Publishing Group Atmospheric carbon dioxide linked  

E-print Network

.29 The relationship between atmospheric carbon dioxide (CO2) and climate in the Quaternary period has been extensively . The range of geological evidence for cool periods during the high CO2 Mesozoic `greenhouse world'2,3 of high and theoretical modelling6,7 . These records indicate that atmospheric CO2 rose from 420 p.p.m.v. in the Triassic

Cai, Long

422

Carbon dioxide fixation by microalgae cultivated in open bioreactors  

Microsoft Academic Search

The biofixation of carbon dioxide (CO2) by microalgae has been proven to be an efficient and economical method, mainly due to the photosynthetic ability of these microorganisms to use this gas as a source of nutrients for their development. The aim of this work was to study the growth of Spirulina LEB18 and Chlorella kessleri microalgae, exposed to controlled and

Ana Priscila Centeno da Rosa; Lisiane Fernandes Carvalho; Luzia Goldbeck; Jorge Alberto Vieira Costa

2011-01-01

423

SELECTIVE OXIDATION IN SUPERCRITICAL CARBON DIOXIDE USING CLEAN OXIDANTS  

EPA Science Inventory

We have systematically investigated heterogeneous catalytic oxidation of different substrates in supercritical carbon dioxide (SC-CO2). Three types of catagysts: a metal complex, 0.5% platinum g-alumina and 0.5% palladium g-alumina were used at a pressure of 200 bar, temperatures...

424

Household carbon dioxide production in relation to the greenhouse effect  

Microsoft Academic Search

A survey of 655 households from eastern suburbs of Melbourne was undertaken to determine householders[prime] attitudes to, and understanding of, the greenhouse effect. Carbon dioxide emissions resulting from car, electricity and gas use were computed and household actions which could reduce CO[sub 2] emissions were addressed. Preliminary analysis of the results indicates that householders in this area are aware of,

D. Stokes; A. Lindsay; J. Marinopoulos; A. Treloar; G. Wescott

1994-01-01

425

Raising the Level of Carbon Dioxide in Your Blood  

NSDL National Science Digital Library

In this activity (on page 146 of the PDF), learners will explore the effects of increased carbon dioxide in the bloodstream. This activity can be enhanced by sharing the "Astronaut's Sleep" Podcast with learners (see related resource link). This resource guide includes background information and sample evaluation questions. Note: learners with respiratory ailments should not participate as subjects.

Marlene Y. MacLeish

2013-05-15

426

Tracing Changes in Ecosystem Function under Elevated Carbon Dioxide Conditions  

NSDL National Science Digital Library

This peer-reviewed article from BioScience journal is on the effects of elevated carbon dioxide on the ecosystem. Responses of ecosystems to elevated levels of atmospheric carbon dioxide (CO2) remain a critical uncertainty in global change research. Two key unknown factors are the fate of carbon newly incorporated by photosynthesis into various pools within the ecosystem and the extent to which elevated CO2 is transferred to and sequestered in pools with long turnover times. The CO2 used for enrichment in many experiments incorporates a dual isotopic tracer, in the sense that ratios of both the stable carbon-13 (13C) and the radioactive carbon-14 (14C) isotopes with respect to carbon-12 are different from the corresponding ratios in atmospheric CO2. Here we review techniques for using 13C and 14C abundances to follow the fate of newly fixed carbon and to further our understanding of the turnover times of ecosystem carbon pools. We also discuss the application of nitrogen, oxygen, and hydrogen isotope analyses for tracing changes in the linkages between carbon, nitrogen, and water cycles under conditions of elevated CO2.

DIANE E. PATAKI, DAVID S. ELLSWORTH, R. DAVE EVANS, MIQUEL GONZALEZ-MELER, JOHN KING, STEVEN W. LEAVITT, GUANGHUI LIN, ROSER MATAMALA, ELISE PENDALL, ROLF SIEGWOLF, CHRIS VAN KESSEL, and JAMES R. EHLERINGER (;)

2003-09-01

427

Supercritical carbon dioxide cycle control analysis.  

SciTech Connect

This report documents work carried out during FY 2008 on further investigation of control strategies for supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle energy converters. The main focus of the present work has been on investigation of the S-CO{sub 2} cycle control and behavior under conditions not covered by previous work. An important scenario which has not been previously calculated involves cycle operation for a Sodium-Cooled Fast Reactor (SFR) following a reactor scram event and the transition to the primary coolant natural circulation and decay heat removal. The Argonne National Laboratory (ANL) Plant Dynamics Code has been applied to investigate the dynamic behavior of the 96 MWe (250 MWt) Advanced Burner Test Reactor (ABTR) S-CO{sub 2} Brayton cycle following scram. The timescale for the primary sodium flowrate to coast down and the transition to natural circulation to occur was calculated with the SAS4A/SASSYS-1 computer code and found to be about 400 seconds. It is assumed that after this time, decay heat is removed by the normal ABTR shutdown heat removal system incorporating a dedicated shutdown heat removal S-CO{sub 2} pump and cooler. The ANL Plant Dynamics Code configured for the Small Secure Transportable Autonomous Reactor (SSTAR) Lead-Cooled Fast Reactor (LFR) was utilized to model the S-CO{sub 2} Brayton cycle with a decaying liquid metal coolant flow to the Pb-to-CO{sub 2} heat exchangers and temperatures reflecting the decaying core power and heat removal by the cycle. The results obtained in this manner are approximate but indicative of the cycle transient performance. The ANL Plant Dynamics Code calculations show that the S-CO{sub 2} cycle can operate for about 400 seconds following the reactor scram driven by the thermal energy stored in the reactor structures and coolant such that heat removal from the reactor exceeds the decay heat generation. Based on the results, requirements for the shutdown heat removal system may be defined. In particular, the peak heat removal capacity of the shutdown heat removal loop may be specified to be 1.1 % of the nominal reactor power. An investigation of the oscillating cycle behavior calculated by the ANL Plant Dynamics Code under specific conditions has been carried out. It has been found that the calculation of unstable operation of the cycle during power reduction to 0 % may be attributed to the modeling of main compressor operation. The most probable reason for such instabilities is the limit of applicability of the currently used one-dimensional compressor performance subroutines which are based on empirical loss coefficients. A development of more detailed compressor design and performance models is required and is recommended for future work in order to better investigate and possibly eliminate the calculated instabilities. Also, as part of such model development, more reliable surge criteria should be developed for compressor operation close to the critical point. It is expected that more detailed compressor models will be developed as a part of validation of the Plant Dynamics Code through model comparison with the experiment data generated in the small S-CO{sub 2} loops being constructed at Barber-Nichols Inc. and Sandia National Laboratories (SNL). Although such a comparison activity had been planned to be initiated in FY 2008, data from the SNL compression loop currently in operation at Barber Nichols Inc. has not yet become available by the due date of this report. To enable the transient S-CO{sub 2} cycle investigations to be carried out, the ANL Plant Dynamics Code for the S-CO{sub 2} Brayton cycle was further developed and improved. The improvements include further optimization and tuning of the control mechanisms as well as an adaptation of the code for reactor systems other than the Lead-Cooled Fast Reactor (LFR). Since the focus of the ANL work on S-CO{sub 2} cycle development for the majority of the current year has been on the applicability of the cycle to SFRs, work has started on modification of the ANL Plant Dynamics Code to allow

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

2011-04-11

428

Tropical deforestation and atmospheric carbon dioxide  

Microsoft Academic Search

Recent estimates of the net release of carbon to the atmosphere from deforestation in the tropics have ranged between 0.4 and 2.5 × 1015 g yr-1. Two things have happened to require a revision of these estimates. First, refinements of the methods used to estimate the stocks of carbon in the vegetation of tropical forests have produced new estimates that

R. A. Houghton

1991-01-01

429

Application of carbon nanotube in wireless sensor network to monitor carbon dioxide  

Microsoft Academic Search

Carbon nanotubes (CNTs) are allotropes of carbon with a cylindrical nanostructure. Over the years, new discoveries have led to new applications, often taking advantage of their unique electrical properties, extraordinary strength and efficiency in heat conduction. Since industrialisation, human activities have resulted in steadily increasing concentrations of the greenhouse gases. Excess amount of carbon dioxide (CO2) in living environment is

Othman Sidek; S. A. Quadri; Shahid Kabir; Muhammad Hassan Bin Afzal

2012-01-01

430

A 400 million year carbon isotope record of pedogenic carbonate: Implications for paleoatmospheric carbon dioxide  

SciTech Connect

A 400 record of atmospheric carbon dioxide levels has been estimated by applying a CO{sub 2} 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 large fluctuations in atmospheric carbon dioxide levels have occurred over the study interval, ranging from the current level up to ten times the current level. Declining pCO{sub 2} levels through the middle Paleozoic culminate in low levels in the Early Permian. An abrupt increase in pCO{sub 2} in the Early Permian is followed by a decrease prior to the Permo-Triassic boundary. Carbon dioxide levels increase through the Triassic to approx. 3,000 ppmV, a level maintained through the Jurassic period. Levels lowered through the Cretaceous, dropping to less than 1,000 ppmV prior to the Cretaceous-Tertiary boundary. Relatively low levels persisted throughout the Cenozoic, with some evidence of higher levels in the Eocene and Oligocene.

Ekart, D.D.; Cerling, T.E.; Montanez, I.P.; Tabor, N.J.

1999-12-01

431

Chalcogen-bonded complexes of some carbon dioxide analogues  

NASA Astrophysics Data System (ADS)

Ab initio calculations have been carried out on the sulphur-bonded van der Waals complexes formed between the carbon dioxide analogues carbonyl sulphide, carbon disulphide and thiocarbonyl selenide, and the common electron donors ammonia, water, phosphine and hydrogen sulphide. The structures of these twelve complexes are all similar, and involve an approximately linear XCS⋯Y fragment (X = O, S, Se; Y = N, O, P, S). These structures contrast with those of the oxygen-bound complexes of carbon dioxide, carbonyl sulphide and carbonyl selenide reported earlier which, with the exception of the hydrogen sulphide species, are characterized by four-membered rings with varying orientations involving the C, O, H and Y atoms. The molecular structures, interaction energies and vibrational spectra have been studied, and the variations in these properties have been correlated with the complex structures and with the molecular quadrupole moments of the acid monomers.

Ramasami, Ponnadurai; Ford, Thomas A.

2014-08-01

432

Geochemical consequences of increased atmospheric carbon dioxide on coral reefs  

USGS Publications Warehouse

A coral reef represents the net accumulation of calcium carbonate (CaCO3) produced by corals and other calcifying organisms. If calcification declines, then reef-building capacity also declines. Coral reef calcification depends on the saturation state of the carbonate mineral aragonite of surface waters. By the middle of the next century, an increased concentration of carbon dioxide will decrease the aragonite saturation state in the tropics by 30 percent and biogenic aragonite precipitation by 14 to 30 percent. Coral reefs are particularly threatened, because reef-building organisms secrete metastable forms of CaCO3, but the biogeochemical consequences on other calcifying marine ecosystems may be equally severe.

Kleypas, J.A.; Buddemeier, R.W.; Archer, D.; Gattuso, J.-P.; Langdon, C.; Opdyke, B.N.

1999-01-01

433

The use of seawater as a carbon dioxide scrubbing medium for underwater life support  

SciTech Connect

Experimental evidence suggests that seawater could be used to scrub carbon dioxide form cabin air in underwater habitats. Seawater has the capacity to absorb carbon dioxide in quantities directly dependent on a number of variables, the most significant of which is the partial pressure of the carbon dioxide in the gas. The absorption capacities of freshwater and seawater are determined in this study in relation to the variables of carbon dioxide partial pressure, water temperature and pH for use in simple engineering design calculations. A conceptual carbon dioxide scrubber is proposed which involves the direct absorption of carbon dioxide in small concentrations in diffused air by a pressurized seawater tower. This conceptual design can potentially offer a low-energy seawater carbon dioxide scrubber to be externally or internally mounted on an underwater habitat.

Nuckols, M.L. [Naval Academy, Annapolis, MD (United States). Dept. of Naval Architecture, Ocean and Marine Engineering

1996-09-01

434

PMEL CO2: Carbon Dioxide Program  

NSDL National Science Digital Library

In order to advance a shared scientific understanding of the ocean's carbon cycle and how it continues to change over time, the National Oceanic and Atmospheric Administration (NOAA) continues to investigate the evolving state of the ocean carbon chemistry with high quality measurements on ships and autonomous platforms. This website provides information on their public outreach efforts, along with news features on how these changes may affect everything from marine animal populations to tourism operations. On the homepage, visitors should check out the "Map & Data Viewer", which allows them to look at the collected carbon data via a 3D projection. The site also contains a "Data Portal" which allows interested parties to examine the data that has been collected thus far, along with historical data sets. The site is rounded out by sections that cover their ongoing research projects and their current observations on these changes.

435

Carbon dioxide clouds in an early dense Martian atmosphere  

NASA Astrophysics Data System (ADS)

We use a time-dependent, microphysical cloud model to study the formation of carbon dioxide clouds in the Martian atmosphere. Laboratory studies by Glandorf et al. [2002] show that high critical supersaturations are required for CO2 cloud particle nucleation and that surface kinetic growth is not limited. These conditions, which are similar to those for cirrus clouds on Earth, lead to the formation of carbon dioxide ice particles with radii greater than 500 ?m and concentrations less than 0.1 cm-3 for typical atmospheric conditions. Within the current Martian atmosphere, CO2 cloud formation is possible at the poles during winter and possibly at high altitudes in the tropics. In both cases, temperature perturbations of several degrees below the CO2 saturation temperature are required to nucleate new cloud particles, suggesting that dynamical processes are the most common initiators of carbon dioxide clouds rather than diabatic cooling. The microphysical cloud model, coupled to a two-stream radiative transfer model, is used to reexamine the impact of CO2 clouds on the surface temperature within a dense CO2 atmosphere. The formation of carbon dioxide clouds leads to a warmer surface than what would be expected for clear sky conditions, but it also warms the atmosphere. The amount of surface warming is sensitive to the presence of dust and water vapor in the atmosphere, both of which act to dampen cloud effects. The radiative warming of the atmosphere associated with cloud formation, as well as latent heating, work to dissipate the clouds when present. In these simulations, clouds never last for periods much longer than several days, limiting their overall effectiveness for warming the surface. The time average cloud optical depth is approximately unity leading to a 5-10 K surface warming, depending on the surface pressure. The surface temperature does not rise above the freezing point of liquid water even for pressures as high as 5 bars, at a solar luminosity of 75% the current value. Our model shows that warming of the surface-atmosphere system by carbon dioxide clouds is self-limiting, since by heating the air the clouds cause themselves to dissipate. However, further analysis of the climatic effects of carbon dioxide clouds considering their global distribution and properties is warranted.

Colaprete, Anthony; Toon, Owen B.

2003-04-01

436

Carbon dioxide clouds in an early dense Martian atmosphere  

NASA Astrophysics Data System (ADS)

We use a time dependent, microphysical cloud model to study the formation of carbon dioxide clouds in the Martian atmosphere. Laboratory studies by Glandorf et al. (2002) show that high critical supersaturations are required for cloud particle nucleation and that surface kinetic growth is not limited. These conditions, which are similar to those for cirrus clouds on Earth, lead to the formation of carbon dioxide ice particles with radii greater than 500 ?m and concentrations less than 0.1 cm-3 for typical atmospheric conditions. Within the current Martian atmosphere, CO2 cloud formation is possible at the poles during winter and possibly at high altitudes in the tropics. In both cases, temperature perturbations of several degrees below the CO2 saturation temperature are required to nucleate new cloud particles suggesting that dynamical processes are the most common initiators of carbon dioxide clouds rather than diabatic cooling. The microphysical cloud model, coupled to a two-stream radiative transfer model, is used to reexamine the impact of CO2 clouds on the surface temperature within a dense CO2 atmosphere. The formation of carbon dioxide clouds leads to a warmer surface than what would be expected for clear sky conditions, but it also warms the atmosphere. The amount of surface warming is sensitive to the presence of dust and water vapor in the atmosphere, both of which act to dampen cloud effects. The radiative warming of the atmosphere associated with cloud formation, as well as latent heating, work to dissipate the clouds when present. In these simulations, clouds never last for periods much longer than several days, limiting their overall effectiveness for warming the surface. The time average cloud optical depth is approximately unity leading to a 5 - 10 K surface warming, depending on the surface pressure. The surface temperature does not rise above the freezing point of liquid water even for pressures as high as 5 bars, at a solar luminosity of 75% the current value. Our model shows that warming of the surface-atmosphere system by carbon dioxide clouds is self-limiting, since by heating the air the clouds cause themselves to dissipate. However, further analysis of the climatic effects of carbon dioxide clouds considering their global distribution and properties is warranted.

Colaprete, A.; Toon, O. B.

2002-12-01

437

Potential carbon dioxide fixation by industrially important microalgae.  

PubMed

The present study aimed at investigating the carbon metabolism in terms of carbon dioxide fixation and its destination in microalgae cultivations. To this purpose, analysis of growth parameters, media of cultivation, biomass composition and productivity and nutrients balance were performed. Four microalgae suitable for mass cultivation were evaluated: Dunaliella tertiolecta SAD-13.86, Chlorella vulgaris LEB-104, Spirulina platensis LEB-52 and Botryococcus braunii SAG-30.81. Global rates of carbon dioxide and oxygen were determinated by a system developed in our laboratory. B. braunii presented the highest CO(2) fixation rate, followed by S. platensis,D. tertiolecta and C. vulgaris (496.98, 318.61, 272.4 and 251.64 mg L(-1)day(-1), respectively). Carbon dioxide fixated was mainly used for microalgal biomass production. Nitrogen, phosphorus (calcium for D. tertiolecta), potassium and magnesium consumption rates (mg gX(-1)) were evaluated for the four microalgae. Biomass composition presented a predominance of proteins but also a high amount of lipids, especially in D. tertiolecta and B. braunii. PMID:20350804

Sydney, Eduardo Bittencourt; Sturm, Wilerson; de Carvalho, Julio Cesar; Thomaz-Soccol, Vanete; Larroche, Christian; Pandey, Ashok; Soccol, Carlos Ricardo

2010-08-01

438

Soil carbon dioxide partial pressure and dissolved inorganic carbonate chemistry under elevated carbon dioxide and ozone.  

PubMed

Global emissions of atmospheric CO(2) and tropospheric O(3) are rising and expected to impact large areas of the Earth's forests. While CO(2) stimulates net primary production, O(3) reduces photosynthesis, altering plant C allocation and reducing ecosystem C storage. The effects of multiple air pollutants can alter belowground C allocation, leading to changes in the partial pressure of CO(2) (pCO(2)) in the soil , chemistry of dissolved inorganic carbonate (DIC) and the rate of mineral weathering. As this system represents a linkage between the long- and short-term C cycles and sequestration of atmospheric CO(2), changes in atmospheric chemistry that affect net primary production may alter the fate of C in these ecosystems. To date, little is known about the combined effects of elevated CO(2) and O(3) on the inorganic C cycle in forest systems. Free air CO(2) and O(3) enrichment (FACE) technology was used at the Aspen FACE project in Rhinelander, Wisconsin to understand how elevated atmospheric CO(2) and O(3) interact to alter pCO(2) and DIC concentrations in the soil. Ambient and elevated CO(2) levels were 360+/-16 and 542+/-81 microl l(-1), respectively; ambient and elevated O(3) levels were 33+/-14 and 49+/-24 nl l(-1), respectively. Measured concentrations of soil CO(2) and calculated concentrations of DIC increased over the growing season by 14 and 22%, respectively, under elevated atmospheric CO(2) and were unaffected by elevated tropospheric O(3). The increased concentration of DIC altered inorganic carbonate chemistry by increasing system total alkalinity by 210%, likely due to enhanced chemical weathering. The study also demonstrated the close coupling between the seasonal delta(13)C of soil pCO(2) and DIC, as a mixing model showed that new atmospheric CO(2) accounted for approximately 90% of the C leaving the system as DIC. This study illustrates the potential of using stable isotopic techniques and FACE technology to examine long- and short-term ecosystem C sequestration. PMID:15378342

Karberg, N J; Pregitzer, K S; King, J S; Friend, A L; Wood, J R

2005-01-01

439

CARBON DIOXIDE AND OUR OCEAN LEGACY  

E-print Network

. Ocean acidification, as the phenomenon is called, over time will create major negative impacts on corals. Ocean acidification and climate change are both effects of excessive carbon dumping into the atmosphere in 2003, and these numbers are growing every year.3 Ocean acidification is a straightforward consequence

440

[Roles of forest management in global carbon dioxide mitigation].  

PubMed

This paper summarized the roles of current forest management measures, e. g., reducing deforestation rate, increasing afforestation and reforestation, strengthening the management of nutrient fertilization, fire hazard, and disease and pest injury, and substituting fossils fuels with charcoal, in global carbon dioxide migration, and analyzed the advantage and insufficiency of China's forest management. The authors indicated that the current forest ecosystems in China, mainly their vegetation carbon pool, played a smaller role of carbon sink in global carbon cycle, and thus, it was important to strengthen the tending of newly cultivated plantation and the management of fire hazard and disease and pest injury, and to increase the carbon sequestration of our forests. PMID:16836107

Hu, Huifeng; Liu, Guohua

2006-04-01

441

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

The objective of this project is to develop a simple, inexpensive process to separate CO{sub 2} as an essentially pure stream from a fossil fuel combustion system using a regenerable, sodium-based sorbent. The sorbent being used in this project is sodium carbonate which is converted to sodium bicarbonate, ''baking soda,'' through reaction with carbon dioxide and water vapor. Sodium bicarbonate is regenerated to sodium carbonate when heated, producing a nearly pure CO{sub 2} stream after condensation of water vapor. Testing conducted previously confirmed that the reaction rate and achievable CO{sub 2} capacity of sodium carbonate decreased with increasing temperature, and that the global rate of reaction of sodium carbonate to sodium bicarbonate increased with an increase in both CO{sub 2} and H{sub 2}O concentrations. Energy balance calculations indicated that the rate of heat removal from the particle surface may determine the reaction rate for a particular particle system. This quarter, thermogravimetric analyses (TGA) were conducted which indicated that calcination of sodium bicarbonate at temperatures as high as 200 C did not cause a significant decrease in activity in subsequent carbonation testing. When sodium bicarbonate was subjected to a five cycle calcination/carbonation test, activity declined slightly over the first two cycles but was constant thereafter. TGA tests were also conducted with two other potential sorbents. Potassium carbonate was found to be less active than sodium carbonate, at conditions of interest in preliminary TGA tests. Sodium carbonate monohydrate showed negligible activity. Testing was also conducted in a 2-inch internal diameter quartz fluidized-bed reactor system. A five cycle test demonstrated that initial removals of 10 to 15 percent of the carbon dioxide in a simulated flue gas could be achieved. The carbonation reaction proceeded at temperatures as low as 41 C. Future work by TGA and in fixed-bed, fluidized-bed, and transport reactor systems is planned to demonstrate the feasibility of this process in large scale operations to separate carbon dioxide from flue gas.

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

2001-10-01

442

Concentration of carbon dioxide by a high-temperature electrochemical membrane cell  

Microsoft Academic Search

The electrochemical carbon dioxide concentrator has emerged over the last few years as the best technique for carbon dioxide control in a manned spacecraft. Preliminary investigations have shown that the Molten Carbonate Fuel Cell (MCFC) can be successfully converted into a molten carbonate CO2 concentrator (MCCDC) for CO2 removal from a space-cabin [1]. The present investigation involved studying the MCCDC

M. P. Kang; J. Winnick

1985-01-01

443

An optimal centralized carbon dioxide repository for Florida, USA.  

PubMed

For over a decade, the United States Department of Energy, and engineers, geologists, and scientists from all over the world have investigated the potential for reducing atmospheric carbon emissions through carbon sequestration. Numerous reports exist analyzing the potential for sequestering carbon dioxide at various sites around the globe, but none have identified the potential for a statewide system in Florida, USA. In 2005, 83% of Florida's electrical energy was produced by natural gas, coal, or oil (e.g., fossil fuels), from power plants spread across the state. In addition, only limited research has been completed on evaluating optimal pipeline transportation networks to centralized carbon dioxide repositories. This paper describes the feasibility and preliminary locations for an optimal centralized Florida-wide carbon sequestration repository. Linear programming optimization modeling is used to plan and route an idealized pipeline network to existing Florida power plants. Further analysis of the subsurface geology in these general locations will provide insight into the suitability of the subsurface conditions and the available capacity for carbon sequestration at selected possible repository sites. The identification of the most favorable site(s) is also presented. PMID:21695024

Poiencot, Brandon; Brown, Christopher

2011-04-01

444

An Optimal Centralized Carbon Dioxide Repository for Florida, USA  

PubMed Central

For over a decade, the United States Department of Energy, and engineers, geologists, and scientists from all over the world have investigated the potential for reducing atmospheric carbon emissions through carbon sequestration. Numerous reports exist analyzing the potential for sequestering carbon dioxide at various sites around the globe, but none have identified the potential for a statewide system in Florida, USA. In 2005, 83% of Florida’s electrical energy was produced by natural gas, coal, or oil (e.g., fossil fuels), from power plants spread across the state. In addition, only limited research has been completed on evaluating optimal pipeline transportation networks to centralized carbon dioxide repositories. This paper describes the feasibility and preliminary locations for an optimal centralized Florida-wide carbon sequestration repository. Linear programming optimization modeling is used to plan and route an idealized pipeline network to existing Florida power plants. Further analysis of the subsurface geology in these general locations will provide insight into the suitability of the subsurface conditions and the available capacity for carbon sequestration at selected possible repository sites. The identification of the most favorable site(s) is also presented. PMID:21695024

Poiencot, Brandon; Brown, Christopher

2011-01-01

445

Colored polymer microparticles through carbon dioxide-assisted dyeing  

SciTech Connect

A new procedure is described for dyeing polymer beads using liquid carbon dioxide as a plasticizer to facilitate transport of dye into the particle phase. Aqueous latexes consisting of monodisperse polystyrene particles with surface-grafted poly(N-vinylpyrrolidone) were dyed with Sudan Red 7B using CO{sub 2} at 25 C and 310 bar. Adding CO{sub 2} to the headspace above the latex resulted in some dyeing of the polymer, but better results were obtained by forming an emulsion of CO{sub 2} in the aqueous latex phase. Emulsions were formed with both a fluorinated and a hydrocarbon-based surfactant. It was found that the carbon dioxide emulsion greatly enhances the transfer of dye into the polystyrene without altering the size or morphology of the particles.

Yates, M.Z.; Birnbaum, E.R.; McCleskey, T.M.

2000-05-30

446

Carbon dioxide concentrations in the environment of sleeping infants.  

PubMed

In 22 infants continuous measurements were made of the concentration of carbon dioxide (CO2) in inspired air during sleep. Evidence was found of CO2 enrichment of inspired air in certain environmental conditions. The levels achieved were not sufficiently high to acutely endanger an infant. Carbon dioxide concentrations as high as 2-3% were observed in the prone position when the infant's head was under a blanket and when the lower face was obscured by bedding. Sleeping prone on a sheepskin also resulted in an increased concentration of CO2 but to a lesser extent than being under a blanket. In awake infants the presence of a pacifier also promoted an excess of CO2 in the inspired air, both in the prone and supine positions. The physiological and clinical implications of these findings, in relation to the Sudden Infant Death Syndrome (SIDS), are unknown and warrant investigation. PMID:8148189

Malcolm, G; Cohen, G; Henderson-Smart, D

1994-02-01

447

Carbon dioxide exchange in a temperate grassland ecosystem  

NASA Technical Reports Server (NTRS)

Carbon dioxide exchange was measured, using the eddy correlation technique, over a tallgrass prairie in northeastern Kansas, U.S.A., during a six-month period in 1987. The diurnal patterns of daytime and nocturnal CO2 fluxes are presented on eight selected days. These days were distributed throughout most of the growing season and covered a wide range of meteorological and soil water conditions. The midday CO2 flux reached a maximum of 1.3 mg/sq m (ground area)/s during early July and was near zero during the dry period in late July. The dependence of the daytime carbon dioxide exchange on pertinent controlling variables, particularly photosynthetically active radiation, vapor pressure deficit, and soil water content is discussed. The nocturnal CO2 flux (soil plus plant respiration) averaged -0.4 m sq m (ground area)/s during early July and was about -0.2 mg sq/m during the dry period.

Kim, Joon; Verma, Shashi B.

1990-01-01

448

Regenerable immobilized aminosilane sorbents for carbon dioxide capture applications  

SciTech Connect

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

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

2014-09-16

449

Supercritical carbon dioxide extraction of solvent from micromachined structures  

SciTech Connect

We have demonstrated that supercritical carbon dioxide extraction can be used for solvent removal to successfully release compliant surface micromachined structures on silicon wafers developed at Sandia National Laboratories. Structures that have been successfully extracted and released include single gear microengines, bridge and cantilever beams, pressure transducers, and experimental comb drive actuators. Since the supercritical fluid has negligible surface tension, it has virtually unabated access to solvent residing in capillary-like spaces as narrow as 1--3 {mu}m under the micromachined features. While conventional drying techniques have been plagued with the collapse and sticking of micromachined structures due to surface tension effects, supercritical carbon dioxide has been shown to reproducibly dry components and test structures, including bridge and cantilever beams approaching 1000 {mu}m in length, without collapsing. The equipment and the extraction process are described, and photographs of supercritically dried test structures and components are presented.

Russick, E.M.; Adkins, C.L.J.; Dyck, C.W.

1995-12-31

450

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

451

Effect of carbon monoxide and nitrogen dioxide on ICR mice  

NASA Technical Reports Server (NTRS)

Times to incapacitation and death and LC(50) values were determined for male ICR mice exposed to different concentration of carbon monoxide for 30 min and of nitrogen dioxide for 10 min in a 4.2 liter hemispherical chamber. The data indicate that ICR mice are more resistant to these two toxicants than Swiss albino mice. The carbon monoxide LC(50) for a 30-min exposure was about 8,000 ppm for ICR mice compared to 3,570 ppm for Swiss albino mice. The nitrogen dioxide LC(50) for a 10-min exposure was above 2,000 ppm for ICR mice compared to about 1,000 ppm for Swiss albino mice.

Hilado, C. J.; Cumming, H. J.

1977-01-01

452

Microbial electrosynthesis of butyrate from carbon dioxide.  

PubMed

This work proves for the first time the bioelectrochemical production of butyrate from CO2 as a sole carbon source. The highest concentration of butyrate achieved was 20.2 mMC, with a maximum butyrate production rate of 1.82 mMC d(-1). The electrochemical characterisation demonstrated that the CO2 reduction to butyrate was hydrogen driven. Production of ethanol and butanol was also observed opening up the potential for biofuel production. PMID:25608945

Ganigué, R; Puig, S; Batlle-Vilanova, P; Balaguer, M D; Colprim, J

2015-02-01

453

Carbon Dioxide Separation with Supported Ionic Liquid Membranes  

SciTech Connect

Supported liquid membranes are a class of materials that allow the researcher to utilize the wealth of knowledge available on liquid properties as a direct guide in the development of a capture technology. These membranes also have the advantage of liquid phase diffusivities higher than those observed in polymeric membranes which grant proportionally greater permeabilities. The primary shortcoming of the supported liquid membranes demonstrated in past research has been the lack of stability caused by volatilization of the transport liquid. Ionic liquids, which possess high carbon dioxide solubility relative to light gases such as hydrogen, are an excellent candidate for this type of membrane since they have negligible vapor pressure and are not susceptible to evaporation. A study has been conducted evaluating the use of several ionic liquids, including 1-hexyl-3-methyl-imidazolium bis(trifuoromethylsulfonyl)imide, 1-butyl-3-methyl-imidazolium nitrate, and 1-ethyl-3-methyl-imidazolium sulfate in supported ionic liquid membranes for the capture of carbon dioxide from streams containing hydrogen. In a joint project, researchers at the University of Notre Dame lent expertise in ionic liquid synthesis and characterization, and researchers at the National Energy Technology Laboratory incorporated candidate ionic liquids into supports and evaluated the resulting materials for membrane performance. Initial results have been very promising with carbon dioxide permeabilities as high as 950 barrers and significant improvements in carbon dioxide/hydrogen selectivity over conventional polymers at 37C and at elevated temperatures. Results include a comparison of the performance of several ionic liquids and a number of supports as well as a discussion of innovative fabrication techniques currently under development.

Luebke, D.R.; Ilconich, J.B.; Myers, C.R.; Pennline, H.W.

2007-04-01

454

Deodorization and deacidification of edible oils with dense carbon dioxide  

Microsoft Academic Search

Near-critical carbon dioxide shows potential for extraction of free fatty acids, off-odors or flavors from edible fats and\\u000a oils. Deacidification and deodorization of a simulated, roasted peanut oil with dense CO2 was performed at various temperatures, pressures and extraction factors in a pilot-scale, packed extraction column with an\\u000a i.d. of 2.86 cm and a height of 162 cm. Pyrazine and

Gregory R. Ziegler; Yi-Jen Liaw

1993-01-01

455

Supercritical carbon dioxide extraction of caffeine from guaraná  

Microsoft Academic Search

A single-pass system was designed to study extraction of caffeine from wet guaraná seeds using supercritical carbon dioxide. Extraction was studied as a function of pressure and temperature to determine caffeine solubility at equilibrium conditions between 136.1 and 272.2 atm and temperatures of 35, 45, and 55 °C. Solubility of caffeine into supercritical CO2 was affected directly by CO2 density.

H. D. Cochran; R BISWAL; J COLLINS

1996-01-01

456

Hot Stuff!: Testing for Carbon Dioxide from Our Own Breath  

NSDL National Science Digital Library

Learners blow into balloons and collect their breath--carbon dioxide gas (CO2). They then blow the CO2 from the balloon into a solution of acid-base indicator. The indicator changes color to show that CO2 gas in water forms an acid. This activity is part of a set of demonstrations and activities that can be used together for a larger lesson. Resource contains vocabulary definitions and suggestions for assessment, extensions, and scaling for different levels of learners.

2014-06-30

457

Supercritical carbon dioxide processed resorbable polymer nanocomposite bone graft substitutes  

Microsoft Academic Search

The development of synthetic bone graft substitutes is an intense area of research due to the complications associated with the harvest of autogenous bone and concerns about the supply of allogenic bone. Porous resorbable polymers have been used extensively in hard tissue engineering applications, but currently lack load-bearing capacity. Supercritical carbon dioxide (scCO2) processing is used as a novel method

Kevin C. Baker; Mihai Manitiu; Robert Bellair; Carly A. Gratopp; Harry N. Herkowitz; Rangaramanujam M. Kannan

2011-01-01

458

Intraoperative events diagnosed by expired carbon dioxide monitoring in children  

Microsoft Academic Search

Expired carbon dioxide measurements (PECO2) were used (1) to assess the adequacy of initial alveolar ventilation, and (2) to document intraoperative airway events and\\u000a metabolic trends. Three hundred and thirty-one children were studied. Thirty-five intraoperative events were diagnosed by\\u000a continuous PeCO2 monitoring; 20 were potentially life-threatening problems (malignant hyperthermia, circuit disconnection or leak, equipment\\u000a failure, accidental extubation, endobronchial intubation, or

Charles J. Coté; Letty M. P. Liu; Stanislaw K. Szyfelbein; Susan Firestone; Nishan G. Goudsouzian; James P. Welch; Alfred L. Daniels

1986-01-01

459

Copper-Catalyzed Carboxylation of Aryl Iodides with Carbon Dioxide  

PubMed Central

A method for carboxylation of aryl iodides with carbon dioxide has been developed. The reaction employs low loadings of copper iodide/TMEDA or DMEDA catalyst, 1 atm of CO2, DMSO or DMA solvent, and proceeds at 25–70 °C. Good functional group tolerance is observed, with ester, bromide, chloride, fluoride, ether, hydroxy, amino, and ketone functionalities tolerated. Additionally, hindered aryl iodides such as iodomesitylene can also be carboxylated PMID:24288654

Tran-Vu, Hung; Daugulis, Olafs

2013-01-01

460

Production and detection of carbon dioxide on Iapetus  

Microsoft Academic Search

Cassini VIMS detected carbon dioxide on the surface of Iapetus during its insertion orbit. We evaluated the CO2 distribution on Iapetus and determined that it is concentrated almost exclusively on Iapetus’ dark material. VIMS spectra show a 4.27-?m feature with an absorption depth of 24%, which, if it were in the form of free ice, requires a layer 31nm thick.

Eric E. Palmer; Robert H. Brown

2011-01-01

461

Upconverting nanoparticle based optical sensor for carbon dioxide  

Microsoft Academic Search

We demonstrate a novel optical sensor for carbon dioxide in concentrations between 0 and 3%. The sensing scheme is based on the optical interrogation of a 12-?m polystyrene (PS) film containing upconverting nanoparticles (UCNPs; 40–100nm in size) of the type NaYF4:Yb,Er, and the longwave absorption pH probe bromothymol blue (BTB) in its anionic (blue) form. PS is chosen as a

Reham Ali; Sayed M. Saleh; Robert J. Meier; Hassan A. Azab; Ibraheim I. Abdelgawad; Otto S. Wolfbeis

2010-01-01

462

Methane conversion with carbon dioxide on nickel aluminides  

NASA Astrophysics Data System (ADS)

The catalytic activity of several samples based on nickel aluminides in methane conversion with carbon dioxide was studied. Nickel aluminides were prepared by the method of self-propagating high-temperature synthesis. The Ni3Al system containing the nickel metal phase exhibited high activity at temperatures above 1073 K. The systems based on Ni2Al3 and NiAl only containing intermetallic compound phases were inactive.

Arkatova, L. A.; Kharlamova, T. S.; Galaktionova, L. V.; Kurina, L. N.; Belousova, V. N.; Naiborodenko, Yu. S.; Kasatskii, N. G.; Golobokov, N. N.

2006-08-01

463

Volcanic carbon dioxide vents show ecosystem effects of ocean acidification  

Microsoft Academic Search

The atmospheric partial pressure of carbon dioxide (pCO2) will almost certainly be double that of pre-industrial levels by 2100 and will be considerably higher than at any time during the past few million years. The oceans are a principal sink for anthropogenic CO2 where it is estimated to have caused a 30% increase in the concentration of H+ in ocean

Jason M. Hall-Spencer; Riccardo Rodolfo-Metalpa; Sophie Martin; Emma Ransome; Maoz Fine; Suzanne M. Turner; Sonia J. Rowley; Dario Tedesco; Maria-Cristina Buia

2008-01-01

464

Electrochemical Cell for Obtaining Oxygen from Carbon Dioxide Atmospheres  

NASA Technical Reports Server (NTRS)

To support human life on the Martian surface, an electrochemical device will be required to obtain oxygen from the carbon dioxide rich atmosphere. The electrolyte employed in such a device must be constructed from extremely thin, dense membranes to efficiently acquire the oxygen necessary to support life. A forming process used industrially in the production of multilayer capacitors and electronic substrates was adapted to form the thin membranes required. The process, known as the tape casting, involves the suspension consisting of solvents and binders. The suspension is passed under a blade, resulting in the production of ceramic membranes between 0.1 and 0.5 mm thick. Once fired, the stabilized zirconia membranes were assembled into the cell design by employing a zirconium phosphate solution as the sealing agent. The resulting ceramic-to-ceramic seals were found to be structurally sound and gas-tight. Furthermore, by using a zirconia-based solution to assemble the cell, the problem of a thermal expansion mismatch was alleviated. By adopting an industrial forming process to produce thin membranes, an electrochemical cell for obtaining oxygen from carbon dioxide was produced. The proposed cell design is unique in that it does not require a complicated manifold system for separating the various gases present in this process, nor does it require a series of complex electrical connections. Thus, the device can reliably obtain the vital oxygen supply from the toxic carbon dioxide atmosphere.

Hooker, Matthew; Rast, H. Edward; Rogers, Darren K.; Borja, Luis; Clark, Kevin; Fleming, Kimberly; Mcgurren, Michael; Oldaker, Tom; Sweet, Nanette

1989-01-01

465

Atlas of high resolution infrared spectra of carbon dioxide  

NASA Technical Reports Server (NTRS)

An atlas of long-path room-temperature absorption spectra of carbon dioxide is presented for the spectral intervals 1830-2100 cm, 2395-2680 cm, and 3140-3235 cm. The spectral data were recorded at high signal to noise with the 0.01 cm resolution Fourier transform interferometer. The spectra were obtained with pressures between 1 and 10 Torr of CO2 and with total paths between 24 and 384 meters. A compilation of the measured line positions and the assignments derived from the analysis are presented. Of the 3336 lines in the atlas, 94 percent were identified as CO2 lines or as residual lines H2O and CO. Calculated positions are presented for the carbon dioxide lines; a total of 52 bands of C-12O2-16, C-13O2-16, C-12O-16O-18, C-12O-16O-17, and C-13O-16O18 were identified. The weakest carbon dioxide lines marked in the atlas have intensities of approximately 0.5 x 10 to the negative 26th power cm/molecule at room temperature.

Rinsland, C. P.; Benner, D. C.; Devi, V. M.; Ferry, P. S.; Sutton, C. H.; Richardson, D. J.

1984-01-01

466

Irreversible climate change due to carbon dioxide emissions.  

PubMed

The severity of damaging human-induced climate change depends not only on the magnitude of the change but also on the pot