Sample records for carbon dioxide laser

  1. Carbon dioxide slab laser

    SciTech Connect

    Tulip, J.

    1988-01-12

    A gas slab laser is described comprising: first and second elongated electrodes each including a planar light reflecting surface disposed so as to form a light guide only in a plane perpendicular to the planar surface and to define a gas discharge gap therebetween; a laser gas disposed in the gap; and means for applying a radio frequency current between the first and second electrodes to establish a laser-exciting discharge in the laser gas.

  2. Laser surgery: using the carbon dioxide laser.

    PubMed Central

    Wright, V. C.

    1982-01-01

    In 1917 Einstein theorized tha through an atomic process a unique kind of electromagnetic radiation could be produced by stimulated emission. When such radiation is in the optical or infrared spectrum it is termed laser (light amplification by stimulated emission of radiation) light. A laser, a high-intensity light source, emits a nearly parallel electromagnetic beam of energy at a given wavelength that can be captured by a lens and concentrated in the focal spot. The wavelength determines how the laser will be used. The carbon dioxide laser is now successfully employed for some surgical procedures in gynecology, otorhinolaryngology, neurosurgery, and plastic and general surgery. The CO2 laser beam is directed through the viewing system of an operating microscope or through a hand-held laser component. Its basic action in tissue is thermal vaporization; it causes minimal damage to adjacent tissues. Surgeons require special training in the basic methods and techniques of laser surgery, as well as in the safety standards that must be observed. Images FIG. 5 PMID:7074503

  3. The carbon dioxide laser scalpel.

    PubMed

    Durante, E J

    1991-12-01

    The CO2-laser is currently used as a scalpel by a large number of medical surgeons, but in the field of veterinary surgery, relatively little has been published on the subject. A review of the origin of medical lasers, the basic physics of laser energy production and the characteristics of laser light was therefore considered necessary. This review includes a discussion on how the optical radiation generated by the different lasers is absorbed, the cutting power of the CO2-laser, and the effect on healing, tensile strength and haemostasis when used in the skin, linea alba and gastrointestinal tract. PMID:1770499

  4. 21 CFR 179.43 - Carbon dioxide laser for etching food.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 2014-04-01 2014-04-01 false Carbon dioxide laser for etching food. 179.43...Radiation and Radiation Sources 179.43 Carbon dioxide laser for etching food. Carbon dioxide laser light may be safely used...

  5. Pulsed-discharge carbon dioxide lasers

    NASA Technical Reports Server (NTRS)

    Willetts, David V.

    1990-01-01

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

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

    PubMed Central

    Monteiro, Luis Silva; Costa, Jos Adriano; da Cmara, Marco Infante; Albuquerque, Rui; Martins, Marco; Pacheco, Jos Jlio; Salazar, Filomena; Figueira, Fernando

    2015-01-01

    Melanic pigmentation results from melanin produced by the melanocytes present in the basal layer of the oral epithelium. One of the most common causes of oral pigmentation is smoker melanosis, a condition associated with the melanocyte stimulation caused by cigarette smoke. This paper aims to illustrate the use of a carbon dioxide laser in the removal of the gingival melanic pigmentation for aesthetic reasons in a 27-year-old female patient with history of a smoking habit. The carbon dioxide laser vaporisation was performed on the gingival mucosa with effective and quick results and without any complications or significant symptoms after the treatment. We conclude that a carbon dioxide laser could be a useful, effective, and safe instrument to treat the aesthetic complications caused by oral smoker melanosis. PMID:25954535

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

    PubMed

    Monteiro, Luis Silva; Costa, Jos Adriano; da Cmara, Marco Infante; Albuquerque, Rui; Martins, Marco; Pacheco, Jos Jlio; Salazar, Filomena; Figueira, Fernando

    2015-01-01

    Melanic pigmentation results from melanin produced by the melanocytes present in the basal layer of the oral epithelium. One of the most common causes of oral pigmentation is smoker melanosis, a condition associated with the melanocyte stimulation caused by cigarette smoke. This paper aims to illustrate the use of a carbon dioxide laser in the removal of the gingival melanic pigmentation for aesthetic reasons in a 27-year-old female patient with history of a smoking habit. The carbon dioxide laser vaporisation was performed on the gingival mucosa with effective and quick results and without any complications or significant symptoms after the treatment. We conclude that a carbon dioxide laser could be a useful, effective, and safe instrument to treat the aesthetic complications caused by oral smoker melanosis. PMID:25954535

  8. Carbon dioxide laser delivery systems in functional paranasal sinus surgery

    NASA Astrophysics Data System (ADS)

    Hoermann, Karl; Stasche, Norbert; Baker-Schreyer, Antonio; Christ, Matthias; Goedert, Paul; Foth, Hans-Jochen

    1994-02-01

    In a limited series of patients, different types of delivery systems for the carbon dioxide laser were evaluated for their clinical efficiency and practicability. The spectrum of disease submitted to laser surgery ranged from recurrent paranasal sinus polyposis to M. Osler. The systems used were an operation microscope with micromanipulator, a handpiece, two rigid, tubular waveguides and one recently developed flexible waveguide. The characteristics of each instrument are discussed, and so are the indications for endonasal laser surgery.

  9. Transition Probabilities between Laser States in Carbon Dioxide

    Microsoft Academic Search

    H. Statz; C. L. Tang; G. F. Koster

    1966-01-01

    Radiative transition probabilities were investigated between certain vibrational levels of carbon dioxide. The number of levels studied was restricted to those that are directly or indirectly involved in the observed laser action. Vibrational wavefunctions were determined by diagonalizing large Hamiltonian matrices (up to 3030). In the Hamiltonian, nonlinear forces were included and the potential energy contained terms up to fourth

  10. Treatment of chronic lip fissures with carbon dioxide laser

    Microsoft Academic Search

    James Combes; Timothy K. Mellor

    2009-01-01

    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

  11. A high-pressure carbon dioxide gasdynamic laser

    NASA Technical Reports Server (NTRS)

    Kuehn, D. M.

    1973-01-01

    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.

  12. Superpulsed carbon dioxide laser: an update on cutaneous surgical applications

    NASA Astrophysics Data System (ADS)

    Wheeland, Ronald G.

    1990-06-01

    Superpulsing the carbon dioxide laser allows delivery of high energy pulses separated by short pauses during which tissue cooling can occur.1 This new technology can provide several important advantages in cutaneous surgery over similar procedures performed with conventional continuous discharge carbon dioxide laser systems. In the excisional mode, there is a two-thirds reduction in thermal necrosis of the wound edge.2 This should translate into more rapid healing3 and increased rate of gain in tensile strength. In the vaporizational mode, precise, superficial and bloodless ablation of multiple benign appendigeal tumors is possible with less thermal damage yielding excellent cosmetic results. The establishment through additional research of accurate laser parameters, pulse duration, peak energy levels, and frequency of pulses, will help improve the specificity of the laser-tissue interaction to provide even better surgical results.

  13. Carbon dioxide gas laser with nuclear pumping

    Microsoft Academic Search

    A. A. Pustovalov; B. M. Smirnov

    1975-01-01

    Calculation of the parameters of a laser consisting of a tube filled with a mixture of helium, nitrogen, and CO2, and excited by a radioactive material covering the walls of the tube. Vibrational excitation of the molecules, raising them to the upper lasing level, takes place via secondary electrons created by ionization of the gas molecules by nuclear particles. The

  14. Measurement of Carbon Dioxide Column via Space Borne Laser Absorption

    NASA Technical Reports Server (NTRS)

    Heaps, WIlliam S.

    2007-01-01

    In order to better understand the budget of carbon dioxide in the Earth's atmosphere it is necessary to develop a global high precision understanding of the carbon dioxide column. In order to uncover the 'missing sink that is responsible for the large discrepancies in the budget as we presently understand it calculation has indicated that measurement accuracy on the order of 1 ppm is necessary. Because typical column average CO2 has now reached 380 ppm this represents a precision on the order of .25% for these column measurements. No species has ever been measured from space at such a precision. In recognition of the importance of understanding the CO2 budget in order to evaluate its impact on global warming the National Research Council in its decadal survey report to NASA recommended planning for a laser based total CO2 mapping mission in the near future. The extreme measurement accuracy requirements on this mission places very strong requirements on the laser system used for the measurement. This work presents an 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.

  15. Carbon dioxide UV laser-induced fluorescence in high-pressure flames

    E-print Network

    Lee, Tonghun

    Carbon dioxide UV laser-induced fluorescence in high-pressure flames W.G. Bessler a , C. Schulz a; in final form 16 May 2003 Published online 10 June 2003 Abstract Laser-induced fluorescence (LIF) of carbon dioxide is investigated with excitation between 215 and 255 nm with spectrally resolved detection in 5

  16. Research of fiber carbon dioxide sensing system based laser absorption spectrum

    NASA Astrophysics Data System (ADS)

    Wei, Yubin; Zhang, Tingting; Li, Yanfang; Zhao, Yanjie; Wang, Chang; Liu, Tongyu

    2012-02-01

    Carbon dioxide is one of the important gas need to be detected in coal mine safety. In the mine limited ventilation environment, Concentration of carbon dioxide directly affects the health of coal miners. Carbon dioxide is also one of important signature Gas in spontaneous combustion forecasting of coal goaf area, it is important to accurately detect concentration of carbon dioxide in coal goaf area. This paper proposed a fiber carbon dioxide online sensing system based on tunable diode laser spectroscopy. The system used laser absorption spectroscopy and optical fiber sensors combined, and a near-infrared wavelength 1608nm fiber-coupled distributed feedback laser (DFB) as a light source and a 7cm length gas cell, to achieve a high sensitivity concentration detection of carbon dioxide gas. The technical specifications of sensing system can basically meet the need of mine safety.

  17. Laser-induced nucleation of carbon dioxide bubbles

    NASA Astrophysics Data System (ADS)

    Ward, Martin R.; Jamieson, William J.; Leckey, Claire A.; Alexander, Andrew J.

    2015-04-01

    A detailed experimental study of laser-induced nucleation (LIN) of carbon dioxide (CO2) gas bubbles is presented. Water and aqueous sucrose solutions supersaturated with CO2 were exposed to single nanosecond pulses (5 ns, 532 nm, 2.4-14.5 MW cm-2) and femtosecond pulses (110 fs, 800 nm, 0.028-11 GW cm-2) of laser light. No bubbles were observed with the femtosecond pulses, even at high peak power densities (11 GW cm-2). For the nanosecond pulses, the number of bubbles produced per pulse showed a quadratic dependence on laser power, with a distinct power threshold below which no bubbles were observed. The number of bubbles observed increases linearly with sucrose concentration. It was found that filtering of solutions reduces the number of bubbles significantly. Although the femtosecond pulses have higher peak power densities than the nanosecond pulses, they have lower energy densities per pulse. A simple model for LIN of CO2 is presented, based on heating of nanoparticles to produce vapor bubbles that must expand to reach a critical bubble radius to continue growth. The results suggest that non-photochemical laser-induced nucleation of crystals could also be caused by heating of nanoparticles.

  18. Ultrapulse Carbon Dioxide Laser Ablation of Xanthelasma Palpebrarum: A Case Series

    PubMed Central

    Pathania, Vikas; Chatterjee, Manas

    2015-01-01

    Context: Xanthelasma palpebrarum is the most common form of xanthomas. Albeit a benign entity, it is cosmetically disturbing and a frequently recurring dermatologic referral. Although the classical treatment option remains surgical excision, alternatively, chemical cauterization, cryosurgery and electrofulguration have all been tried in the past with mixed results. The use of laser systems such as carbon dioxide laser, Erb:YAG laser, Q-switched Nd:YAG laser, diode laser, pulsed dye laser and KTP laser have become popular in the treatment of these lesions. Recent literature suggests minimal pigmentary changes and scarring with the use of ultrapulse carbon dioxide laser treatment of these lesions. Aim: To study and evaluate the effectiveness of ultrapulse carbon dioxide laser ablation for treatment of xanthelasma palpebrarum. Materials and Methods: 10 patients presenting with bilateral xanthelasma palpebrarum, new and with recurrence were studied for results after a single treatment with ultrapulse carbon dioxide laser (10,600 nm; 100-200 Hz; 200-400 ?sec). The follow-up time was 9 months. Results: All lesions were treatable with a single-laser treatment session. Two patients (20%) developed recurrence during the follow-up period. Side effects included post inflammatory hyperpigmentation in two patients (20%), but no visible scarring was observed. Conclusions: The ultrapulse carbon dioxide laser is an effective and safe therapeutic alternative in treatment of xanthelasma palpebrarum. PMID:25949023

  19. Clinical study on 71 anorectal cases treated by carbon dioxide laser

    NASA Astrophysics Data System (ADS)

    Li, Gui-hua

    1993-03-01

    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.

  20. Carbon dioxide laser and Apligraf for a painful plantar hypertrophic scar.

    PubMed

    Lee, Daniel K; Serkin, Arnold L

    2004-01-01

    We report on a patient with a large, painful hypertrophic scar on the plantar aspect of the left foot who was treated with carbon dioxide laser and a skin substitute (Apligraf) and followed up for longer than 1 year. To our knowledge, no other case reports have been published on the use of a skin substitute to gain coverage and resolution after excision of a hypertrophic scar by carbon dioxide laser. PMID:14729994

  1. Pulsed laser annealing of sodium super ionic conductor for carbon dioxide sensors

    Microsoft Academic Search

    Shi-Chien Kao; Guo-Dung John Su

    2010-01-01

    This paper discussed a way to improve solid electrolyte carbon dioxide (CO2) sensor by excimer laser annealing of sodium super ionic conductors (NASICON). The CO2 sensor used in this paper consists of a thin NASICON layer. We additionally annealed the NASICON to improve its electrical conductivity by pulsed excimer laser. The laser annealing results in re-crystallization of the NASICON thin

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

    PubMed

    Raiti, Paul

    2008-06-01

    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

  3. Long-Term Results of Ultrapulsed Carbon Dioxide Laser Resurfacing of the Mediterranean Face

    Microsoft Academic Search

    mer ?ensz; Cihat Nazmi Baran; Murat ?ahin Alagz; Ahmet a?ri Uysal; Ramazan Erkin nl

    2004-01-01

    Background In Mediterranean countries, increased exposure to sunlight accelerates aging of the skin and the formation of wrinkles. The long-term follow-up results for the patients who underwent resurfacing with ultrapulsed carbon dioxide (CO 2) laser are presented. Methods All 47 patients who underwent ultrapulsed CO 2 laser between 1994 and 1996 were included in the study. The patients were photographed

  4. Carbon dioxide

    NSDL National Science Digital Library

    Arie Melamed-Katz (None; )

    2007-06-19

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

  5. Differential Absorption Measurements of Carbon Dioxide for Carbon Sequestration Site Monitoring Using a Temperature Tunable Diode Laser

    Microsoft Academic Search

    S. D. Humphries; A. R. Nehrir; K. S. Repasky; J. L. Carlsten; L. H. Spangler; L. M. Dobeck; J. A. Shaw

    2007-01-01

    Carbon capture and sequestration in geologic formations provides a method to remove carbon dioxide (CO2) from entering the Earth's atmosphere. An important issue for the successful storage of CO2 is the ability to monitor geologic sequestration sites for leakage to verify site integrity. A differential absorption measurement instrument based on a continuous wave (cw) temperature tunable distributed feedback (DFB) laser

  6. Cavity enhanced absorption spectroscopy of molecular carbon dioxide near IR region with a DFB diode laser

    Microsoft Academic Search

    Shixin Pei; Xiaoming Gao; Fenping Cui; Wei Huang; Jie Shao; Teng Huang; Weixiong Zhao; Weijun Zhang

    2005-01-01

    This paper is about cavity enhanced absorption spectroscopy (CEAS) experiment with a tunable narrow line width continuous wave DFB diode laser and it was used to measure the weak absorption band of carbon dioxide in the near infrared region. The absorption spectrum was extracted from the measurement of light intensity that leaks out of an optical cavity which was consisted

  7. Automatic Resonator Alignment and Power Stabilization of High Power Carbon Dioxide Lasers

    Microsoft Academic Search

    Dale Richard Akitt

    1992-01-01

    The high power carbon dioxide laser has become a very important tool in the area of industrial materials processing. This is due primarily to the enormous optical intensities which the device can attain. Unfortunately, it has proved increasingly difficult to construct machines capable of maintaining a consistently uniform output beam at elevated power levels, for extended periods. These difficulties are

  8. Hypertrophic scar formation following carbon dioxide laser ablation of plantar warts in cyclosporin-treated patients.

    PubMed

    Ozluer, S M; Chuen, B Y; Barlow, R J; Markey, A C

    2001-12-01

    We present four renal transplant patients who developed hypertrophic scars following carbon dioxide laser ablation of recalcitrant plantar warts. All of the patients were on long-term treatment with cyclosporin, which we believe to be responsible. We discuss several possible mechanisms by which cyclosporin may influence wound healing and scarring. PMID:11899123

  9. Performance of an exhaled nitric oxide and carbon dioxide sensor using quantum cascade laser-

    E-print Network

    Performance of an exhaled nitric oxide and carbon dioxide sensor using quantum cascade laser- based in asthma and other respiratory disorders. The optical performance of a NO/CO2 sensor employing integrated-time NO and CO2 measurements in a single breath cycle is reported. A NO noise-equivalent concentration of 0.4 ppb

  10. Tunable diode laser high resolution spectroscopic measurements of the nu sub 2 vibration of carbon dioxide

    Microsoft Academic Search

    J. R. Aronson; P. C. von Thuna; J. F. Butler

    1975-01-01

    A tunable diode laser spectrometer was used for high resolution measurements on the Q-branch of the nu sub 2 vibration of carbon dioxide. The infrared source was a current-tuned Pb\\/0.936\\/Sn\\/0.064\\/Se diode laser. A 1-m gas cell was designed to allow variation of temperature (200-300 K) at 1-50 torr of 320 ppm mixtures in nitrogen. Owing to the narrow linewidth of

  11. In situ high P-T Raman spectroscopy and laser heating of carbon dioxide Mario Santoro,a)

    E-print Network

    Lin, Jung-Fu "Afu"

    In situ high P-T Raman spectroscopy and laser heating of carbon dioxide Mario Santoro,a) Jung interpretation of the high P-T phase diagram of carbon dioxide. Furthermore, our approach opens a new way. The transformation temperature threshold and the transformation dynamics from the molecular phases III and II

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

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    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.

  13. Effects of carbon dioxide, Nd-YAG, and argon laser radiation on coronary atheromatous plaques.

    PubMed

    Abela, G S; Normann, S; Cohen, D; Feldman, R L; Geiser, E A; Conti, C R

    1982-12-01

    Laser radiation has been successfully applied in several areas of medical practice. However, its use in cardiology and specifically its effects on obstructive atherosclerosis have largely been unexplored. To evaluate effects of laser radiation on atherosclerotic plaques 25 fresh necropsy atherosclerotic coronary artery segments were exposed to laser radiation with either a carbon dioxide, Nd-YAG, or argon laser. Split or intact segments were prepared under dry conditions or while immersed in saline solution or blood and exposed to laser radiation as power and duration of exposure varied. All 3 lasers were capable of creating controlled injury to atherosclerotic plaques. In general, the magnitude of injury varied according to the total energy delivered (that is, power times duration of exposure. Calcified and noncalcified plaques were penetrated with similar levels of injury. Histologic examination demonstrated that laser radiation produced a wedge incision in the atherosclerotic plaque which was surrounded by zones of thermal and acoustic injury. PMID:6816057

  14. Direct determination of carbon dioxide in aqueous solution using mid-infrared quantum cascade lasers.

    PubMed

    Schaden, S; Haberkorn, M; Frank, J; Baena, J R; Lendl, B

    2004-06-01

    A method for the direct determination of carbon dioxide in aqueous solutions using a room-temperature mid-infrared (MIR) quantum cascade laser at 2330 cm(-1) is reported. The absorption values of different carbon dioxide concentrations were measured in a 119 microm CaF2 flow-through cell. An optical system made of parabolic mirrors was used to probe the flow cell and to focus the laser beam on the mercury cadmium telluride (MCT) detector. Aqueous carbon dioxide standards were prepared by feeding different mixtures of gaseous N2 and CO2 through wash bottles at controlled temperature. The concentration of the dissolved CO2 was calculated according to Henry's law, taking into account the temperature and the partial pressure of CO2. The carbon dioxide standards were connected via a selection valve to a peristaltic pump for subsequent, automated measurement in the flow-through cell. A calibration curve was obtained in the range of 0.338 to 1.350 g/L CO2 with a standard deviation of the method sxo equal to 19.4 mg/L CO2. The limit of detection was calculated as three times the baseline noise over time and was determined to be 39 mg/L. PMID:15198817

  15. Threshold Levels for Damage of the Cornea following Irradiation by a Continuous Wave Carbon Dioxide (10.6 m) Laser

    Microsoft Academic Search

    R. G. Borland; D. H. Brennan; A. N. Nicholson

    1971-01-01

    CORNEAL damage of varying severity has been studied in the rabbit (Cuniculus oryctolagus) and monkey (Macaca mulatto) following exposure to a continuous wave carbon dioxide (10.6 m) laser. The laser consisted of a 1.5 m glass tube with a water cooled jacket. The tube contained a mixture of carbon dioxide (partial pressure 0.64 mm Hg), nitrogen (partial pressure 1.28 mm

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

    PubMed Central

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

    2013-01-01

    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. PMID:25606307

  17. Design of catalytic monoliths for closed-cycle carbon dioxide lasers

    NASA Technical Reports Server (NTRS)

    Herz, Richard K.

    1988-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

    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.

  19. Phase aberrations and beam cleanup techniques in carbon-dioxide laser fusion systems

    SciTech Connect

    Viswanathan, V.K.

    1981-01-01

    This paper describes the various carbon dioxide laser fusion systems at Los Alamos from the point of view of an optical designer. The types of phase aberrations present in these systems, as well as the beam cleanup techniques that can be used to improve the beam optical quality, are discussed. As this is a review article, some previously published results are also used where relevant.

  20. The 2014 ASCENDS Field Campaign - a Carbon Dioxide Laser Absorption Spectrometer Perspective

    NASA Astrophysics Data System (ADS)

    Spiers, G. D.; Menzies, R. T.; Jacob, J. C.; Geier, S.; Fregoso, S. F.

    2014-12-01

    NASA's ASCENDS mission has been flying several candidate lidar instruments on board the NASA DC-8 aircraft to obtain column integrated measurements of Carbon Dioxide. Each instrument uses a different approach to making the measurement and combined they have allowed for the informed development of the ASCENDS mission measurement requirements(1). The JPL developed Carbon Dioxide Laser Absorption Spectrometer, CO2LAS is one of these instruments. The CO2LAS measures the weighted, column averaged carbon dioxide between the aircraft and the ground using a continuous-wave heterodyne technique. The instrument operates at a 2.05 micron wavelength optimized for enhancing sensitivity to boundary layer carbon dioxide. Since the 2013 field campaign the instrument has undergone significant upgrades that improve the data collection efficiency and instrument stability and has recently been re-integrated onto the NASA DC-8 for the August 2014 ASCENDS field campaign. This presentation will summarize the instrument and algorithm improvements and review the 2014 field campaign flights and preliminary results. (1) Abshire, J.B. et al., "An overview of NASA's ASCENDS Mission lidar measurement requirements", submitted to 2014 Fall AGU Conference.

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

    NASA Astrophysics Data System (ADS)

    Chan, Kenneth H.; Fried, Daniel

    2011-03-01

    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.

  2. Ceramic bracket debonding with the carbon dioxide laser

    Microsoft Academic Search

    Jeff L. Rickabaugh; Roy D. Marangoni; Kristine K. McCaffrey

    1996-01-01

    The conventional removal of ceramic brackets can be complicated by bracket fracture or enamel loss. To ease this ceramic bracket removal, lasers have been previously investigated for thermally softening thermally the bonding resin. This conversion of laser light to heat can also threaten the vitality of the debonded teeth. Pilot studies and computer modeling suggest that for commonly used polycrystalline

  3. Transoral carbon-dioxide laser resection of hypopharyngeal carcinoma

    Microsoft Academic Search

    Heinrich H. Rudert; Steffen Hft

    2003-01-01

    In hypopharyngeal carcinoma, open partial resection is rarely feasible because of the high rate of chronic aspiration. Transoral laser surgery, however, is not associated with major swallowing problems. Between 1991 and 1995, a total of 29 patients with cancer of the hypopharynx were treated using laser surgical resection. In 25 patients, a neck dissection was performed, and 26 patients were

  4. Carbon dioxide laser in ophthalmic plastic and orbital surgery.

    PubMed

    Wesley, R E; Bond, J B

    1985-10-01

    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

  5. Carbon dioxide laser absorption spectra of toxic industrial compounds

    SciTech Connect

    Loper, G.L.; Sasaki, G.R.; Stamps, M.A.

    1982-05-01

    CO/sub 2/ laser absorption cross-section data are reported for acrolein, styrene, ethyl acrylate, trichloroethylene, vinyl bromide, and vinylidene chloride. These data indicate that sub parts per billion level, interference-free detection limits should be possible for these compounds by the CO/sub 2/ laser photoacoustic technique. Photoacoustic detectabilities below 40 ppb should be possible for these compounds in the presence of ambient air concentrations of water vapor and other anticipated interferences. These compounds are also found not to be important inerference in the detection of toxic hydrazine-based rocket fuels by CO/sub 2/ laser spectroscopic techniques.

  6. Transoral carbon-dioxide laser resection of hypopharyngeal carcinoma.

    PubMed

    Rudert, Heinrich H; Hft, Steffen

    2003-04-01

    In hypopharyngeal carcinoma, open partial resection is rarely feasible because of the high rate of chronic aspiration. Transoral laser surgery, however, is not associated with major swallowing problems. Between 1991 and 1995, a total of 29 patients with cancer of the hypopharynx were treated using laser surgical resection. In 25 patients, a neck dissection was performed, and 26 patients were radiated postoperatively. The 5-year overall survival was 48% and tumor-related survival 58%. The outcome was significantly ( P<0.048) dependent on the preoperative lymph node status (N(0)=74%, N(+)=34% overall survival). Accordingly, the 5-year survival in stage I and stage II tumors was 71% and in stage III and IV tumors 47%. The highest local control rate was achieved in patients with carcinoma of the hypopharyngeal walls. A major advantage of laser surgery is that resurfacing of the wounds takes place per secundam. No reconstructions with free vascularized grafts have to be performed. There were no functional deficits regarding speech and swallowing in 94%, 100% and 100% of the surviving patients without local recurrence after 3, 4 and 5 years, respectively. No patient had to have a tracheostomy intraoperatively. Laser surgical treatment in combination with neck dissection and postoperative radiotherapy of selected patients with early cancer of the hypopharynx shows comparable results with open surgical procedures and is superior to radiotherapy alone. Given the low postoperative morbidity, transoral laser surgery with the goal of preserving the larynx should gain more importance in the future. PMID:12709803

  7. Carbon dioxide laser backscatter signatures from laboratory-generated dust

    NASA Astrophysics Data System (ADS)

    Walter, D. P.; Cooper, D. E.; van der Laan, J. E.; Murray, E. R.

    1986-08-01

    A dual CO2 laser system was used to measure aerosol backscatter spectral signatures from dust minerals (kaolin, illite, montmorillonite, colemanite, and limestone) as well as from a soil sample from Dugway Proving Ground, UT. Complex refractive indices measured from bulk samples of the materials, and particle size distributions measured with a cascade impactor, were used to compute theoretical backscatter spectra using Mie theory. The measured signatures agreed well with calculated signatures for most minerals and the soil sample. The experiment demonstrated the feasibility of detecting the compositional elements of dust using a CO2 laser-based system.

  8. Carbon dioxide sequestration monitoring and verification via laser based detection system in the 2 mum band

    NASA Astrophysics Data System (ADS)

    Humphries, Seth David

    Carbon Dioxide (CO2) is a known contributor to the green house gas effect. Emissions of CO2 are rising as the global demand for inexpensive energy is placated through the consumption and combustion of fossil fuels. Carbon capture and sequestration (CCS) may provide a method to prevent CO2 from being exhausted to the atmosphere. The carbon may be captured after fossil fuel combustion in a power plant and then stored in a long term facility such as a deep geologic feature. The ability to verify the integrity of carbon storage at a location is key to the success of all CCS projects. A laser-based instrument has been built and tested at Montana State University (MSU) to measure CO2 concentrations above a carbon storage location. The CO2 Detection by Differential Absorption (CODDA) Instrument uses a temperature-tunable distributed feedback (DFB) laser diode that is capable of accessing a spectral region, 2.0027 to 2.0042 mum, that contains three CO2 absorption lines and a water vapor absorption line. This instrument laser is aimed over an open-air, two-way path of about 100 m, allowing measurements of CO2 concentrations to be made directly above a carbon dioxide release test site. The performance of the instrument for carbon sequestration site monitoring is studied using a newly developed CO2 controlled release facility. The field and CO2 releases are managed by the Zero Emissions Research Technology (ZERT) group at MSU. Two test injections were carried out through vertical wells simulating seepage up well paths. Three test injections were done as CO2 escaped up through a slotted horizontal pipe simulating seepage up through geologic fault zones. The results from these 5 separate controlled release experiments over the course of three summers show that the CODDA Instrument is clearly capable of verifying the integrity of full-scale CO2 storage operations.

  9. Carbon dioxide laser backscatter signatures from laboratory-generated dust

    Microsoft Academic Search

    D. P. Walter; D. E. Cooper; J. E. van der Laan; E. R. Murray

    1986-01-01

    A dual CO2 laser system was used to measure aerosol backscatter spectral signatures from dust minerals (kaolin, illite, montmorillonite, colemanite, and limestone) as well as from a soil sample from Dugway Proving Ground, UT. Complex refractive indices measured from bulk samples of the materials, and particle size distributions measured with a cascade impactor, were used to compute theoretical backscatter spectra

  10. High-pressure carbon dioxide electrically excited preionization lasers

    Microsoft Academic Search

    N. G. Basov; M Belenov; V. A. Danilychev; A. F. Suchkov

    1975-01-01

    A review is given of the results of theoretical and experimental investigations of electrically excited preionization gas lasers in which the pressure in the working mixture may reach tens of atmospheres. The method of preionization by external agency is considered and it is reported that, under optimal conditions, practically 100% of the electrical pump energy can be converted into the

  11. a Study of the Carbon Dioxide Laser Near Threshold

    Microsoft Academic Search

    David Wilson Bromley

    1991-01-01

    When the cavity losses of a laser are varied across threshold there is a delay in its bifurcation. We studied the effects of sweeping the cavity losses with an Acousto -Optic Modulator. For very high frequencies, Q-Switching occurs and the delay is dependent upon the depth of modulation. For medium frequencies, the delay is dependent upon the frequency. For lower

  12. Carbon dioxide laser irradiation of bacterial targets in vitro

    SciTech Connect

    Byrne, P.O.; Sisson, P.R.; Oliver, P.D.; Ingham, H.R.

    1987-05-01

    Agar targets seeded with Escherichia coli and Staphylococcus aureus in roll tubes simulating the vaginal vault were irradiated with a CO/sub 2/ laser at various power densities and durations. Viable bacteria were detected in the plume emissions in all instances. Staphylococcus aureus was found to be more resistant to the thermal effects of lasing than E. coli. This suggests that CO/sub 2/ irradiation of cervical lesions could disseminate viable particles which may be a hazard for patients and operators.

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

    NASA Technical Reports Server (NTRS)

    Spiers, Gary D.; Menzies, Robert T.

    2008-01-01

    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.

  14. Carbon Dioxide Laser Absorption Spectrometer (CO2LAS) Aircraft Measurements of CO2

    NASA Technical Reports Server (NTRS)

    Christensen, Lance E.; Spiers, Gary D.; Menzies, Robert T.; Jacob, Joseph C.; Hyon, Jason

    2011-01-01

    The Jet Propulsion Laboratory Carbon Dioxide Laser Absorption Spectrometer (CO2LAS) utilizes Integrated Path Differential Absorption (IPDA) at 2.05 microns to obtain CO2 column mixing ratios weighted heavily in the boundary layer. CO2LAS employs a coherent detection receiver and continuous-wave Th:Ho:YLF laser transmitters with output powers around 100 milliwatts. An offset frequency-locking scheme coupled to an absolute frequency reference enables the frequencies of the online and offline lasers to be held to within 200 kHz of desired values. We describe results from 2009 field campaigns when CO2LAS flew on the Twin Otter. We also describe spectroscopic studies aimed at uncovering potential biases in lidar CO2 retrievals at 2.05 microns.

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

    SciTech Connect

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

    1991-05-01

    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.

  16. Study on ceramic coating on the enamel surface using a carbon dioxide laser.

    PubMed

    Nihei, Tomotaro; Kurata, Shigeaki; Ohashi, Katsura; Umemoto, Kozo; Teranaka, Toshio

    2011-01-01

    The aims of this study were to evaluate a new restorative method using a carbon dioxide laser (CO(2)-laser) and to evaluate the acid resistance of teeth. Experimental calcium phosphate glass (CPG) powder and two low melting point ceramics (Finesse and zirconium silicate) were fused to enamel surfaces using a CO(2)-laser at an irradiation intensity of 1.0 watt for 30 seconds with a beam size of 0.49 mm at the focal point. The treated teeth were observed with a scanning electron microscope, and the acid resistance of the treated enamel surfaces was evaluated. The CPG fused successfully to the enamel surface, and the treated enamel surface showed high acid resistance compared with the low melting point ceramics and the non-irradiated surfaces. This system may lead to the development of new restorative methods that do not require the use of bonding agents. PMID:21422667

  17. Laser therapy for the treatment of Hailey-Hailey disease: a systematic review with focus on carbon dioxide laser resurfacing.

    PubMed

    Falto-Aizpurua, L A; Griffith, R D; Yazdani Abyaneh, M A; Nouri, K

    2015-06-01

    Benign familial chronic pemphigus, or Hailey-Hailey disease (HHD), is a recurrent bullous dermatitis that tends to have a chronic course with frequent relapses. Long-term treatment options include surgery with skin grafting or dermabrasion. Both are highly invasive and carry significant risks and complications. More recently, 'laser-abrasion' has been described as a less invasive option with a better side-effect profile. In this article, we systematically review the safety and efficacy of carbon dioxide laser therapy as a long-term treatment option for HHD, as well as provide a review of other lasers that have been reported with this goal. A total of 23 patients who had been treated with a carbon dioxide laser were identified. After treatment, 10 patients (43%) had had no recurrence, 10 (43%) had greater than 50% improvement, 2 (8%) had less than 50% improvement and 1 (4%) patient had no improvement at all (follow-up period ranged from 4 to 144months). Laser parameter variability was wide and adverse effects were minimal, including dyspigmentation and scarring. Reviewed evidence indicates this therapy offers a safe, effective treatment alternative for HHD with minimal risk of side-effects. Larger, well-designed studies are necessary to determine the optimal treatment parameters. PMID:25418614

  18. Microvascular anastomosis using carbon dioxide (CO2) laser: evaluation by SEM after corrosion cast.

    PubMed

    Travers, V; Kanaujia, R R; Ochi, M; Ikuta, Y

    1987-10-01

    In order to compare the carbon dioxide laser-assisted microvascular anastomosis (CO2 LAMA) with conventional microvascular sutured anastomosis (CMSA), 40 microarterial anastomoses were performed in Wistar albino rats. At different time intervals from zero to four weeks after the procedure, the anastomoses were examined under the scanning electron microscope (SEM) after resin corrosion cast (Mercox). CO2 LAMA was easier and less time-consuming than CMSA, with the same patency rate. Healing of the lumen surface was similar in both procedures, suggesting that CO2 LAMA can be reliably used in microvascular anastomosis. PMID:3681829

  19. Design of catalytic monoliths for closed-cycle carbon dioxide lasers

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    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.

  20. Monolith catalysts for closed-cycle carbon dioxide lasers

    NASA Technical Reports Server (NTRS)

    Herz, Richard K.; Badlani, Ajay

    1991-01-01

    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.

  1. Histologic evaluation of the width of soft tissue necrosis adjacent to carbon dioxide laser incisions

    SciTech Connect

    Pogrel, M.A.; McCracken, K.J.; Daniels, T.E. (Univ. of California, San Francisco (USA))

    1990-11-01

    This study evaluated the width of tissue necrosis lateral to carbon dioxide laser incisions on human intraoral excisional biopsy specimens. Measurements were made on specimens including epithelium, muscle, dense and loose connective tissue, and salivary gland. Results showed a mean width of tissue necrosis of 86 microns in epithelium, 85 microns in muscle, 51 microns in loose connective tissue, 96 microns in dense connective tissue, and 41 microns in salivary gland. The range of thermal necrosis in different tissue types is probably based on the water content within each type. A cellular partially homogenized zone of reversible thermal damage up to 500 microns in width was visible adjacent to the zone of thermal necrosis. The relatively narrow width of tissue necrosis with this technique may account for the claimed superior properties of laser-induced wounds compared with those created by electrosurgery.

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

    SciTech Connect

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

    1990-06-01

    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.

  3. Carbon dioxide concentrator

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

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

  4. Use of a carbon dioxide laser for treatment of recurrent laryngeal papillomatosis in small children: Experiences with an anaesthetic technique

    Microsoft Academic Search

    P. M. Spargo; M. S. Nielsen; J. A. S. Carruth

    1986-01-01

    The carbon dioxide laser offers advantages in the treatment of recurrent laryngeal papillomatosis in small children. These advantages include precision, haemostasis and minimal surrounding tissue oedema. These patients do, however, present problems to the anaesthetist; this paper outlines a suitable anaesthetic technique and describes experience of its use in five children on 63 occasions.

  5. Infectious papillomavirus in the vapor of warts treated with carbon dioxide laser or electrocoagulation: Detection and protection

    Microsoft Academic Search

    W. S. Sawchuk; P. J. Weber; D. R. Lowy; L. M. Dzubow

    1989-01-01

    Papillomavirus DNA has been reported recently in the vapor (smoke plume) derived from warts treated with carbon dioxide laser; this raises concerns for operator safety. We therefore have studied a group of human and bovine warts to define further the potential risk of wart therapy and to test whether a surgical mask could reduce exposure. Half of each wart was

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

    NASA Astrophysics Data System (ADS)

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

    1996-04-01

    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.

  7. Effect of carbon dioxide laser treatment on lesion progression in an intraoral model

    NASA Astrophysics Data System (ADS)

    Featherstone, John D. B.; Fried, Daniel; Gansky, Stuart A.; Stookey, George K.; Dunipace, Ann J.

    2001-04-01

    Previous studies have shown that pretreatment of dental enamel by specific carbon dioxide laser conditions inhibited subsequent progression of caries-like lesions in vitro. The aim of the present study was to use an intra-oral model to determine whether similar inhibition is observed in the human mouth. A cross over study with 23 subjects and three regimens was used. Pre-formed varies-like lesions were made in extracted human enamel and exposed intra-orally in partial dentures in each subject to A) placebo dentifrice and no laser treatment, B) placebo dentifrice following laser pretreatment, or C) sodium fluoride dentifrice and no laser treatment during each of three study periods. Samples were assessed by micro radiography to compare the mineral loss before and after each treatment and drive a net change in mineral value. Overall P was not significantly different form L but both P and L were different from F. For those subjects who demineralized in P, L and F were significantly better than P, with L showing an 84 percent inhibition of further demineralization, but no enhancement of demineralization.

  8. 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.

  9. Dynamics of pulsed laser ablation in high-density carbon dioxide including supercritical fluid state

    NASA Astrophysics Data System (ADS)

    Urabe, Keiichiro; Kato, Toru; Stauss, Sven; Himeno, Shohei; Kato, Satoshi; Muneoka, Hitoshi; Baba, Motoyoshi; Suemoto, Tohru; Terashima, Kazuo

    2013-10-01

    To gain a better understanding of pulsed laser ablation (PLA) processes in high-density fluids, including gases, liquids, and supercritical fluids (SCFs), we have investigated the PLA dynamics in high-density carbon dioxide (CO2) using a time-resolved shadowgraph (SG) observation method. The SG images revealed that the PLA dynamics can be categorized into two domains that are separated by the gas-liquid coexistence curve and the Widom line, which forms a border between the gaslike and liquidlike domains of an SCF. Furthermore, a cavitation bubble observed in liquid CO2 near the critical point exhibited a particular characteristic: the formation of an inner bubble and an outer shell structure. The results indicate that the thermophysical properties of the reaction field generated by PLA can be dynamically tuned by controlling the solvent temperature and pressure, particularly near the critical point.

  10. Carbon Dioxide Removal

    NSDL National Science Digital Library

    American Museum of Natural History

    In this experiment, students 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. Students will learn that the carbon cycle is a fundamental Earth process. Throughout Earth's history, the balance of carbon has kept the atmosphere's carbon dioxide (CO2) and Earth's temperature within relatively narrow ranges.

  11. Capturing Carbon Dioxide

    NSDL National Science Digital Library

    Austen Saltz

    2010-01-01

    In this activity, learners investigate carbon sequestration by creating a carbonated beverage out of apple juice and dry ice. This experiment illustrates how carbon dioxide can be stored in a substance. Learners compare and contrast the results to determine if liquid carbonation is an effective method for carbon sequestration. Safety note: this activity involves dry ice; please follow recommended guidelines.

  12. Carbon Dioxide Fountain

    ERIC Educational Resources Information Center

    Kang, Seong-Joo; Ryu, Eun-Hee

    2007-01-01

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

  13. Production of Carbon Dioxide

    NSDL National Science Digital Library

    The Science House

    2014-01-28

    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.

  14. 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.

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

    PubMed

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

    2015-01-01

    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

  16. Indoor carbon dioxide monitoring with diode laser absorption at 2 ?m

    NASA Astrophysics Data System (ADS)

    Li, Jinyi; Du, Zhenhui; Ma, Yiwen; Liu, Jingwang

    2015-05-01

    In order to investigate the variation of indoor carbon dioxide concentration and how it changes with human activities, a tunable diode laser absorption spectroscopy (TDLAS) system was used to monitor the indoor CO2 concentration. Based on Wavelength Modulation Spectroscopy double frequency detection (WMS-2f), the 2v1+v3 characteristic line (4991.26 cm-1) of CO2 was measured by a DFB laser. The measured concentration values were calibrated by means of a cell filled with reference gas. The results show that the daily average indoor CO2 concentrations is about 419ppm which is slightly higher than that of the outdoor and the changing range is between 380ppm and 510ppm in a day. The indoor CO2 concentration was influenced by the change of ventilation and indoor staff. The respiration of the indoor staff makes a greater impact on a relatively confined indoor CO2 concentration. The CO2 increasing rate is measured to be 80ppm/hour in the case of occupant density of 0.06 people/m3. Therefore, the staff crowded indoor should ventilate timely to prevent excessive CO2 causing people discomfort.

  17. Laser Based Instruments Using Differential Absorption Detection for Above and Below Ground Monitoring of Carbon Dioxide

    Microsoft Academic Search

    S. D. Humphries; J. L. Barr; K. S. Repasky; J. L. Carlsten; L. H. Spangler; L. M. Dobeck

    2008-01-01

    Carbon capture and sequestration in geologic formations provides a method to remove carbon dioxide (CO2) from entering the Earth's atmosphere. An important issue for the successful storage of CO2 is the ability to monitor geologic sequestration sites for leakage to verify site integrity. A field site for testing the performance of CO2 detection instruments and techniques has been developed by

  18. The application of a carbon dioxide laser in the treatment of superficial oral mucosal lesions.

    PubMed

    Huang, Zhiquan; Wang, Youyuan; Liang, Qixiang; Zhang, Liping; Zhang, Daming; Chen, Weiliang

    2015-05-01

    To evaluate the safety and advantages of using carbon dioxide (CO2) laser in the treatment of oral mucosal lesion, including vascular malformations, precancerous lesions, and verrucous nevus, a retrospective analysis was conducted for 73 patients with oral mucosal lesions who received CO2 laser treatment during June 2012 to December 2013, including 25 patients with vascular malformations, 22 patients with oral leukoplakia, 18 patients with oral mucosal lichen planus, and 8 patients with oral mucosal and labial mucosal verrucous nevus. The lesions ranged from 0.8??0.8?cm to 4??3?cm. Twenty patients with lesions removed using the traditional scalpel, assisted with an electric knife, were the control group. The operative time was from 3 to 10 minutes, with an average of 5.5 minutes; the average amount of intraoperative bleeding was 5?mL. None of the 73 patients had postoperative infections, and all wounds healed well after the surgery. The patients were followed up for 1 year. Two patients with oral leukoplakia showed recurrence after the surgery, and a reoperation achieved satisfactory treatment effects. The operative time of the control group was in the range of 4 to 15 minutes, with an average of 9.5 minutes, and the average amount of intraoperative bleeding was 10?mL. None of the 20 patients had postoperative infections, and the wounds also showed healing well after the surgery. The application of CO2 laser in the treatment of oral mucosal lesions has the advantages of reduced bleeding, a clear view during surgery, and a shorter operative time. PMID:25974830

  19. Laser Based Instruments Using Differential Absorption Detection for Above and Below Ground Monitoring of Carbon Dioxide

    NASA Astrophysics Data System (ADS)

    Humphries, S. D.; Barr, J. L.; Repasky, K. S.; Carlsten, J. L.; Spangler, L. H.; Dobeck, L. M.

    2008-12-01

    Carbon capture and sequestration in geologic formations provides a method to remove carbon dioxide (CO2) from entering the Earth's atmosphere. An important issue for the successful storage of CO2 is the ability to monitor geologic sequestration sites for leakage to verify site integrity. A field site for testing the performance of CO2 detection instruments and techniques has been developed by the Zero Emissions Research Technology (ZERT) group at Montana State University. A field experiment was conducted at the ZERT field site beginning July 9th, 2008 and ending August 7th, 2008 to test the performance of several CO2 detection instruments. The field site allows a controlled flow rate of CO2 to be released underground through a 100 m long horizontal pipe placed below the water table. A flow rate of 0.3 tons CO2/day was used for the entirety of this experiment. This paper describes the results from two laser based instruments that use differential absorption techniques to determine CO2 concentrations in real time both above and below the ground surface. Both instruments use a continuous wave (cw) temperature tunable distributed feedback (DFB) laser capable of tuning across several CO2 and water vapor absorption features between at 2003 nm and 2006 nm. The first instrument uses the DFB laser to measure path integrated atmospheric concentrations of CO2. The second instrument uses the temperature tunable DFB laser to monitor underground CO2 concentrations using a buried photonic bandgap optical fiber. The above ground instrument operated nearly continuously during the CO2 release experiment and an increase in atmospheric CO2 concentration above the release pipe of approximately 2.5 times higher than the background was observed. The underground instrument also operated continuously during the experiment and saw an increase in underground CO2 concentration of approximately 15 times higher than the background. These results from the 2008 ZERT field experiment demonstrate the potential for these instruments to be used for CO2 monitoring of sequestration sites.

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

    NASA Technical Reports Server (NTRS)

    Singh, Upendra N.

    2011-01-01

    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.

  1. Carbon dioxide removal process

    DOEpatents

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

    2003-11-18

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

  2. Differential Absorption Measurements of Carbon Dioxide for Carbon Sequestration Site Monitoring Using a Temperature Tunable Diode Laser

    NASA Astrophysics Data System (ADS)

    Humphries, S. D.; Nehrir, A. R.; Repasky, K. S.; Carlsten, J. L.; Spangler, L. H.; Dobeck, L. M.; Shaw, J. A.

    2007-12-01

    Carbon capture and sequestration in geologic formations provides a method to remove carbon dioxide (CO2) from entering the Earth's atmosphere. An important issue for the successful storage of CO2 is the ability to monitor geologic sequestration sites for leakage to verify site integrity. A differential absorption measurement instrument based on a continuous wave (cw) temperature tunable distributed feedback (DFB) laser has been developed for measuring atmospheric concentrations of CO2. The tunable DFB laser is capable of tuning across two CO2 absorption features at 2003.50 nm and 2004.02 nm. The measured normalized transmission through the atmosphere is then related to the atmospheric concentration of CO2 through the line strength and normalized line width associated with each absorption feature. A description of this instrument will be presented including the instrument design, operation, and performance characteristics. A field site for testing the performance of CO2 detection instruments and techniques has been developed by the Zero Emissions Research Technology (ZERT) group at Montana State University. The field site allows a controlled flow rate of CO2 to be released underground through a 100 m long horizontal pipe placed below the water table. Two release experiments were performed this past summer with flow rates of 0.1 and 0.3 tons CO2/day. The first release experiment lasted ten days while the second release lasted seven days. Measurements taken with the differential absorption instrument over the horizontal well during these release experiments showed an increase of greater than 300 parts per million (ppm) over the background CO2 concentration. These results indicate the capabilities of the above ground differential absorption instrument for carbon sequestration site monitoring.

  3. Carbon dioxide sensor

    DOEpatents

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

    2011-11-15

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

  4. Pulsed carbon dioxide laser for cartilage vaporization and subchondral bone perforation in horses. Part II: Morphologic and histochemical reactions.

    PubMed

    Nixon, A J; Krook, L P; Roth, J E; King, J M

    1991-01-01

    A pulsed carbon dioxide laser was used to vaporize articular cartilage in four horses, and perforate the cartilage and subchondral bone in four horses. Both intercarpal joints were examined arthroscopically and either a 1 cm cartilage crater or a series of holes was created in the third carpal bone of one joint. The contralateral carpus served as a control. After euthanasia at week 8, the treated and control joints were examined for gross changes, and samples of cartilage and subchondral bone, synovial membrane, and peripheral lymph nodes were examined histologically. Depletion of cartilage matrix glycosaminoglycan was assessed by safranin-O histochemical staining of the laser site and adjacent cartilage. Cartilage removal by laser vaporization resulted in rapid regrowth, with fibrous and fibrovascular tissue and occasional regions of fibrocartilage at week 8. The subchondral bone, synovial membrane, and draining lymph nodes appeared essentially unaffected by the laser cartilage vaporization procedure. Conversely, carbon dioxide laser drilling of subchondral bone resulted in poor penetration, extensive areas of thermal necrosis of bone, and significant secondary damage to the apposing articular surface of the radial carpal bone. PMID:1712998

  5. Carbon dioxide recycling

    EPA Science Inventory

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

  6. Carbon Dioxide Exercise

    NSDL National Science Digital Library

    Randy Richardson

    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.

  7. 8, 73157337, 2008 Carbon dioxide

    E-print Network

    Paris-Sud XI, Universit de

    ACPD 8, 73157337, 2008 Carbon dioxide distributions over Europe C. Gurk et al. Title Page Abstract distributions of carbon dioxide over Europe C. Gurk1 , H. Fischer1 , P. Hoor1 , M.G. Lawrence1 , J. Lelieveld1 Publications on behalf of the European Geosciences Union. 7315 #12;ACPD 8, 73157337, 2008 Carbon dioxide

  8. Arnold Schwarzenegger THE CARBON DIOXIDE

    E-print Network

    i Arnold Schwarzenegger Governor THE CARBON DIOXIDE ABATEMENT POTENTIAL OF CALIFORNIA'S MID, Afzal Siddiqui, and Judy Lai. 2011. The Carbon Dioxide Abatement Potential of California's Mid/Agricultural/Water EndUse Energy Efficiency Renewable Energy Technologies Transportation The Carbon Dioxide

  9. High-Performance Carbon Monoxide Oxidation Catalysts Engineered for Carbon Dioxide Lasers

    Microsoft Academic Search

    Steven Dwayne Gardner

    1990-01-01

    The low-temperature CO oxidation activity of numerous materials has been evaluated in order to develop efficient catalysts for use in CO_2 lasers. The materials were screened for activity in small, stoichiometric concentrations of CO and O_2 at temperatures near 55^circC. An Au\\/MnO_{rm x} catalyst was synthesized which exhibited exceptional CO oxidation activity while maintaining negligible performance decay over a period

  10. 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.

  11. Bench Remarks: Carbon Dioxide.

    ERIC Educational Resources Information Center

    Bent, Henry A.

    1987-01-01

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

  12. Correction method of bending loss in the hollow optical fiber for endoscopic submucosal dissection using carbon dioxide laser

    NASA Astrophysics Data System (ADS)

    Kusakari, Daisuke; Hazama, Hisanao; Awazu, Kunio

    2015-03-01

    Endoscopic submucosal dissection using carbon dioxide laser is a promising treatment of early digestive cancer because it can avoid the risk of perforation. Although a hollow optical fiber transmitting mid-infrared light has been used, it was observed that the irradiation effect was influenced by bending a gastrointestinal gastrointestinal endoscope due to the change in transmittance by the bending loss. Therefore, we quantitatively evaluated the change in the irradiation effect by bending the hollow optical fiber in the gastrointestinal endoscope and proposed a correction method to stabilize the irradiation effect. First, the relationship between the irradiated laser energy density and the incision depth for porcine stomach was measured by bending the head of the gastrointestinal endoscope. Next, the relationship between the bending angle of the head of the gastrointestinal endoscope and the temperature rise of the hollow optical fiber in the head of the gastrointestinal endoscope was measured during the laser irradiation. As a result, the laser energy density and the incision depth decreased as the bending angle increased, and linear correlation between the laser energy density and the incision depth was observed. It was found that the bending angle can be estimated by the ratio of the setting laser power to time derivative of the temporal profile of the temperature of the hollow optical fiber. In conclusion, it is suggested that the correction of the laser energy density and stabilization of the incision capability is possible by measuring the temporal profile of the temperature of the hollow optical fiber.

  13. Modeling of carbon monoxide oxidation kinetics over NASA carbon dioxide laser catalysts

    NASA Technical Reports Server (NTRS)

    Herz, Richard K.

    1989-01-01

    The recombination of CO and O2 formed by the dissociation of CO2 in a sealed CO2 laser discharge zone is examined. Conventional base-metal-oxide catalysts and conventional noble-metal catalysts are not effective in recombining the low O2/CO ratio at the low temperatures used by the lasers. The use of Pt/SnO2 as the noble-metal reducible-oxide (NMRO), or other related materials from Group VIIIA and IB and SnO2 interact synergistically to produce a catalytic activity that is substantially higher than either componet separately. The Pt/SnO2 and Pd/SnO2 were reported to have significant reaction rates at temperatures as low as -27 C, conditions under which conventional catalysts are inactive. The gas temperature range of lasers is 0 + or - 40 C. There are three general ways in which the NMRO composite materials can interact synergistically: one component altering the properties of another component; the two components each providing independent catalytic functions in a complex reaction mechanism; and the formation of catalytic sites through the combination of two components at the atomic level. All three of these interactions may be important in low temperature CO oxidation over NMRO catalysts. The effect of the noble metal on the oxide is discussed first, followed by the effect of the oxide on the noble metal, the interaction of the noble metal and oxide to form catalytic sites, and the possible ways in which the CO oxidation reaction is catalyzed by the NMRO materials.

  14. Carbon dioxide dangers demonstration model

    USGS Publications Warehouse

    Venezky, Dina; Wessells, Stephen

    2010-01-01

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

  15. Recent progress in development of a laser based, ultra-high precision isotope monitor for carbon dioxide

    NASA Astrophysics Data System (ADS)

    Nelson, David; McManus, Barry; Herndon, Scott; Zahniser, Mark

    2015-04-01

    Greenhouse gas (GHG) emissions are the primary drivers of global climate change and hence there is a crucial need to quantify their sources and sinks. A general technique to help constrain source and sink strengths in GHG exchange processes is the analysis of the relative proportions of isotopic variants of GHG's. Very high precision measurements of isotopologue ratios are necessary in order to identify sources and sinks because the characteristic changes are small. The standard method of isotopologue measurement has been mass spectrometry, but this technique typically requires significant sample preparation and relatively high instrument maintenance. Laser spectroscopy has the potential to ease these burdens and also to allow easy separation of interfering isobars such as 13C-CO2 and 17O-CO2. We present recent results demonstrating ultra-high precision measurements of carbon dioxide isotope ratios which have the potential to rival the accuracy of mass spectrometric measurements. These measurements were performed using Tunable Infrared Laser Direct Absorption Spectroscopy (TILDAS). We have obtained isotopic measurement precisions of ~10 per meg for both 13C-CO2 and 18O-CO2 while measuring ambient air samples with continuous flow. We have also developed a method for analyzing air samples from canisters by alternately and rapidly trapping sample gas and reference gas in the optical cell. The ultimate goal is to create an automated, ultra-high accuracy carbon dioxide isotope monitor able to quantify small (~100 standard ml), discreet air samples. We will also discuss current instrument performance results and prospects for the measurement of the clumped isotopes of carbon dioxide in ambient air samples.

  16. Carbon Dioxide Landscape

    NASA Technical Reports Server (NTRS)

    2005-01-01

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

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

  17. CARBON DIOXIDE FIXATION.

    SciTech Connect

    FUJITA,E.

    2000-01-12

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

  18. InGaAs\\/InGaAsP Quantum Well Laser at 2.04 mum for Diode Spectroscopy of Carbon Dioxide Isotope

    Microsoft Academic Search

    Akinori Ubukata; Jie Dong; Katsumasa Suzuki; Koh Matsumoto

    2001-01-01

    We demonstrate the utility of a compressively strained InGaAs\\/InGaAsP laser emitting at 2.05 mum for diode spectroscopy of carbon dioxide isotope (13CO2). By applying a highly compressive strain to and using thick wells in the active layer, the extension of the laser emission wavelength beyond 2.0 mum is achieved. The threshold current is as low as 6 mA at 283

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

    PubMed Central

    2014-01-01

    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 20102013. 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

  20. Carbon Dioxide Reduction Through Urban Forestry

    E-print Network

    Standiford, Richard B.

    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

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

    SciTech Connect

    Viswanathan, V.K.

    1981-01-01

    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.

  2. Carbon dioxide and climate

    SciTech Connect

    Not Available

    1990-10-01

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

  3. Carbon dioxide and terrestrial ecosystems

    Microsoft Academic Search

    G. W. Koch; H. A. Mooney

    1996-01-01

    This book is a summary of the current research which addresses the effects of elevated carbon dioxide on terrestrial ecosystems and an identification of significant unresolved issues. Chapters address the carbon dioxide effects on trees and forests, unmanaged herbaceous ecosystems, and crops. Included are experimental studies, conceptual models, general mathematical models, dynamic simulation models.

  4. Carbon Dioxide: Friend or Foe?

    Microsoft Academic Search

    C. Muller

    1983-01-01

    Carbon Dioxide: Friend or Foe is a short rnonograph on the so-called carbon dioxide greenhouse effect. The author challenges the established view that the present CO2 increase would, in the long term, lead to a global ground temperature increase. S. B. Idso, from four sets of observations, has deduced that the temperature response to an increased received energy at the

  5. Carbon Dioxide Capture and Disposal

    Microsoft Academic Search

    K. S. Lackner

    2002-01-01

    Unless carbon dioxide from fossil fuel combustion is captured and disposed of safely and permanently, the concerns over climate change will eventually lead to the demise of fossil fuels. Because of their importance in today's energy market the phasing out of fossil fuels would likely precipitate a major energy crisis. Mineral sequestration and extraction of carbon dioxide from the air

  6. Coral reefs and carbon dioxide

    SciTech Connect

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

    1996-03-01

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

  7. Effect of smoke evacuation on limiting thermal damage when using the carbon dioxide laser for cutaneous surgery

    NASA Astrophysics Data System (ADS)

    Waters, Ruth A.; Thomas, J. M.; Clement, Marc; Davies, S.

    1990-06-01

    We have conducted a study of the use of the carbon dioxide (C02) laser for ablation of multiple cutaneous recurrences of melanoma. Lesions of primary malignant melanoma are usually widely excised to try and prevent local recurrence. Despite this, recurrent cutaneous lesions do occur. These lesions may be small and numerous making local excision impractical. Hyperthermic isolated limb perfusion has shown some success in controlling the local disease but this procedure has a significant morbidty, some patients show only a limited response and post-perfusion recurrences are common.1 Also, in some patients, thelesions will not be confined to a limb. No other method of local control has provided an ideal solution and amputation has sometimes been a last resort. We have therefore selected patients for laser ablation if they have had lesions too numerous for local excision, or have had recurrences following perfusion or were otherwise suitable for perfusion. The lesions were vaporized under local or general anaesthesia according to their size and number. The wounds were then left to heal by secondary intention. Simple dry dressings were applied and all patients were discharged home within 24 hours. In total we have treated over 1,500 lesions in 30 patients. The results of the initial study have been very encouraging. The procedure is quick and simple with absent or minimal post-operative pain. Although the incidence of recurrent tumour at a previously lasered site is less than 1%, new tumours may develop at other sites. These are amenable to further laser treatment.

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

    PubMed Central

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

    2014-01-01

    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 1214 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 3385 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 5070 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

  9. Use of a carbon dioxide laser for surgical management of cutaneous masses in horses: 65 cases (1993-2004)

    NASA Astrophysics Data System (ADS)

    Hawkins, Jan F.; McCauley, Charles T.

    2005-04-01

    The purpose of this study was to evaluate the outcome of horses treated for cutaneous masses with the carbon dioxide (CO2) laser. The records of 65 horses were examined. Surgery was performed under general anesthesia or standing under sedation and local anesthesia. Excision was performed freehand using a focused beam with power settings ranging from 10 to 32 Watts in a continuous mode. Following en bloc removal of masses the subcutaneous tissue and wound margins were photovaporized using a defocused beam. Follow-up information was obtained via telephone interview with owners or referring veterinarians Cutaneous masses were divided into three groups: sarcoid (29), neoplasia including squamous cell carcinoma (15), melanoma (6), schwanoma (2), fibroma (1), and fibrosarcoma (1), and non-neoplastic masses (11). Mass reoccurrence developed in 8 of 29 (28%) sarcoids and 4 of 14 (29%) squamous cell carcinoma. No reoccurrence was reported for horses diagnosed with melanoma, schwanoma, fibrosarcoma, fibroma, or any of the non-neoplastic masses. Sixty of 63 owners (95%) reported that they were satisfied with the outcome of the procedure. This study demonstrates that the CO2 laser is an effective means of treating cutaneous masses in horses.

  10. Carbon Dioxide Landscape

    NASA Technical Reports Server (NTRS)

    2004-01-01

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

  11. Dissociation and regeneration kinetics of carbon dioxide in the active medium of sealed-off transverse RF-excited CO{sub 2} lasers

    SciTech Connect

    Vesnov, I G [Ryazan State Radio Engineering University (Russian Federation)

    2010-06-23

    An improved mathematical model describing the dissociation and regenerations kinetics of carbon dioxide in the active medium of sealed-off transverse RF-excited CO{sub 2} lasers is presented. It is shown that the calculation of the active medium composition of such lasers requires the equations of the gas-mixture kinetics to take into account the diffuse flow of oxygen atoms on metal electrodes and on the surface of heterogeneous catalysts used to reduce the degree of the carbon dioxide dissociation. The rate constants of the heterogeneous recombination reaction CO + O {yields} CO{sub 2} on the surface of alumina ceramics and Al{sub 2}O{sub 3} are determined. (active media)

  12. Homogeneous hydrogenation of carbon dioxide

    Microsoft Academic Search

    Philip G. Jessop; Takao. Ikariya; Ryoji. Noyori

    1995-01-01

    Carbon dioxide (CO) is of the greatest interest as a C feedstock because of the vast amounts of carbon which exist in this form and because of the low cost of bulk CO. Currently, toxic carbon monoxide, the main competitor for many processes, is used in industry instead because CO is perceived to be less reactive and its efficient catalytic

  13. NASA Satellite Sees Carbon Dioxide

    NSDL National Science Digital Library

    2012-08-03

    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.

  14. A semiconductor injection-switched high-pressure sub-10-picosecond carbon dioxide laser amplifier

    Microsoft Academic Search

    Michael Kon Yew Hughes

    2002-01-01

    A multiatmospheric-pressure-broadened CO2 laser amplifier was constructed to amplify sub-10-picosecond pulses generated with semiconductor switching. High-intensity, mid-infrared, amplified pulses have many applications: especially in fields such as non-linear optics, laser-plasma interaction, and laser particle acceleration. The injected pulses are produced by exciting GaAs (or an engineered, fast-recombination time semiconductor) with an ultrafast visible laser pulse to induce transient free carriers

  15. Development of a gas-based spectral filter for carbon dioxide laser produced plasma extreme ultraviolet sources

    NASA Astrophysics Data System (ADS)

    Mbanaso, Chimaobi

    Currently, extreme ultraviolet (EUV) lithography is a promising next generation lithography technique for enabling the scaling of device features beyond 22 nm. Out-of-band radiation in EUV exposure tools remains one of the critical issues that must be addressed before the implementation of this lithography technique for high volume manufacturing. Laser produced plasmas which use a carbon dioxide (CO2) drive laser pulse are more likely to be used to generate EUV radiation because of their scalability to higher source power. The out-of-band spectrum at the intermediate focus of EUV sources that use a CO2 laser produced plasma is dominated by scattered radiation from the drive laser which operates near 10.6 microm wavelength. The unmitigated infrared radiation causes deformation of the optics in the lithography scanner making it difficult to maintain stringent overlay specifications. EUV transmission losses incurred as a result of using existing solid filters is of concern due to the limited source power currently achievable in these exposure tools. This research work investigated the use of infrared absorbing gaseous species to spectrally reduce the unwanted CO2 laser light reaching the intermediate focus. The spectral attractiveness of an infrared absorbing gas, sulfur hexafluoride, was evaluated based on the measured absorption cross section at wavelengths around 13.5 nm and 10.6 mum in custom optical systems. Based on the results acquired from the built systems, it was possible to predict the suppression of infrared radiation near 10.6 mum wavelength as well as the EUV transmission losses as a function of different gas densities. As part of this work, gas-based diffusion barriers were considered for inhibiting the molecular transport of the infrared absorbing species to other regions of the EUV system. An experimental configuration equipped with a quadruple mass spectrometer was designed to characterize and test the functionality of a magnetically confined plasma discharge to inhibit gaseous transport. The results indicated ionization and directional molecular collisions as factors that contribute towards establishing a gas density gradient due to the presence of an argon plasma discharge.

  16. Carbon Dioxide Sequestration Industrial-scale processes are available for separating carbon dioxide from the post-

    E-print Network

    Carbon Dioxide Sequestration Industrial-scale processes are available for separating carbon dioxide dioxide separation and sequestration because the lower cost of carbon dioxide separation from for injection of carbon dioxide into oil or gas-bearing formations. An advantage of sequestration involving

  17. Molecular Structure of Carbon Dioxide

    NSDL National Science Digital Library

    2002-08-15

    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.

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

    NASA Astrophysics Data System (ADS)

    Young, William P.

    2000-05-01

    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.

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

    E-print Network

    Saleska, Scott

    A high precision pulsed quantum cascade laser spectrometer for measurements of stable isotopes problem opens the possibility of field worthy rapid response isotopic instrumentation and attests to the maturity of these lasers as spectroscopic sources. 1. Introduction The measurement of isotopic ratios

  20. Comparative bactericidal exposures for selected oral bacteria using carbon dioxide laser radiation

    Microsoft Academic Search

    Douglas N. Dederich; Michael A. Pickard; Allison S. Vaughn; John Tulip; Kenneth L. Zakariasen

    1990-01-01

    Although relatively high CO laser energies have been shown to sterilize root canals, the response of several bacterial strains to decreasing exposures of CO laser energy remains unknown. Freshly grown bacterial cells were irradiated on glass microscope coverslips. A comparison of equivalent energy exposures with differing parameters was made on the bacterial viability. No statistically significant difference was found in

  1. Carbon dioxide laser tuning through 110 lines in 3 ms for airborne remote sensing.

    PubMed

    Eberhardt, J E; Haub, J G; Whitbourn, L B

    1988-03-01

    Rapid tuning of a 3-m long glow discharge excited CO(2) laser is achieved by a rotating polygonal mirror scanning the intracavity beam across a diffraction grating. The system can tune through 110 different rotational lines spanning wavelengths from 9.2 to 11.1 microm in 3 ms with typical peak powers of 100-500 W at burst repetition rates up to 360 Hz and is suitable for airborne remote sensing. The effects of laser output coupler reflectance, burst rate, scan direction, and current modulation are investigated, and the performance of an optimized system for mineral reflectance measurements is presented. A reflection spectrum of a shale obtained with the rapidly tuned laser at a range of 5 m is shown to compare well to data gathered for the same sample using a slowly tuned cw CO(2) laser. PMID:20523703

  2. Seventh International Carbon Dioxide Conference

    NSDL National Science Digital Library

    Organized by NOAA's Climate Monitoring and Diagnostic Laboratory (CMDL), the Seventh International Carbon Dioxide Conference is planned September 25-30 in Broomfield, Colo. At this website, scientists involved in various aspects of the global carbon cycle, especially the current increases of carbon dioxide in the atmosphere, are encouraged to attend. Users can read the preliminary announcement and can learn about the themes of the conference. Researchers can learn about abstract submissions and accommodations. The Brief Conference History link offers a nice synopsis of the accomplishments of past conferences.

  3. Carbon dioxide laser absorption spectra and low ppb photoacoustic detection of hydrazine fuels

    Microsoft Academic Search

    G. L. Loper; A. R. Calloway; M. A. Stamps; J. A. Gelbwachs

    1980-01-01

    Absorption cross-section data are reported for the toxic rocket fuels hydrazine, monomethylhydrazine, and unsymmetrical dimethylhydrazine (UDMH), as well as for their selected air oxidation products dimethylamine, trimethylamine, and methanol at up to seventy-eight CO laser wavelengths each. These data are important for the assessment of the capability of CO laser-based spectroscopic techniques for monitoring low levels of hydrazine-fuel vapors in

  4. Carbon dioxide recovery by vacuum swing adsorption

    Microsoft Academic Search

    Cheng-Tung Chou; Chao-Yuh Chen

    2004-01-01

    According to an investigation by the Intergovernmental Panel on Climate Change (IPCC), carbon dioxide is the most significant greenhouse gas produced as a result of human activities. The amount of carbon dioxide emissions has to be reduced to meet global treaty. The concentration and recovery of carbon dioxide from flue gases is the first important step in solving the carbon

  5. Carbon dioxide laser absorption spectra and low ppb photoacoustic detection of hydrazine fuels

    SciTech Connect

    Loper, G.L.; Calloway, A.R.; Stamps, M.A.; Gelbwachs, J.A.

    1980-08-15

    Absorption cross-section data are reported for the toxic rocket fuels hydrazine, monomethylhydrazine, and unsymmetrical dimethylhydrazine (UDMH), as well as for their selected air oxidation products dimethylamine, trimethylamine, and methanol at up to seventy-eight CO/sub 2/ laser wavelengths each. These data are important for the assessment of the capability of CO/sub 2/ laser-based spectroscopic techniques for monitoring low levels of hydrazine-fuel vapors in the ambient air. Interference-free detection sensitivities of <30 ppb have been demonstrated for UDMH using a laboratory photoacoustic detection system.

  6. Carbon dioxide laser absorption spectra and low ppb photoacoustic detection of hydrazine fuels.

    PubMed

    Loper, G L; Calloway, A R; Stamps, M A; Gelbwachs, J A

    1980-08-15

    Absorption cross-section data are reported for the toxic rocket fuels hydrazine, monomethylhydrazine, and unsymmetrical dimethylhydrazine (UDMH), as well as for their selected air oxidation products dimethylamine, trimethylamine, and methanol at up to seventy-eight CO(2) laser wavelengths each. These data are important for the assessment of the capability of CO(2) laser-based spectroscopic techniques for monitoring low levels of hydrazine-fuel vapors in the ambient air. Interference-free detection sensitivities of <30 ppb have been demonstrated for UDMH using a laboratory photoacoustic detection system. PMID:20234499

  7. Comparative bactericidal exposures for selected oral bacteria using carbon dioxide laser radiation

    SciTech Connect

    Dederich, D.N.; Pickard, M.A.; Vaughn, A.S.; Tulip, J.; Zakariasen, K.L. (Univ. of Alberta, Edmonton (Canada))

    1990-01-01

    Although relatively high CO{sub 2} laser energies have been shown to sterilize root canals, the response of several bacterial strains to decreasing exposures of CO{sub 2} laser energy remains unknown. Freshly grown bacterial cells were irradiated on glass microscope coverslips. A comparison of equivalent energy exposures with differing parameters was made on the bacterial viability. No statistically significant difference was found in the energy required to kill closely related bacterial species. However, the energy density required to kill greater than 99.5% of the bacteria is less than 200 J/cm{sup 2}, much less than that shown to sterilize in a previous study.

  8. REVIEWS OF TOPICAL PROBLEMS: High-pressure carbon dioxide electrically excited preionization lasers

    Microsoft Academic Search

    N. G. Basov; . M. Belenov; V. A. Danilychev; A. F. Suchkov

    1975-01-01

    A review is given of the results of theoretical and experimental investigations of electrically excited preionization gas lasers in which the pressure in the working mixture may reach tens of atmospheres. The method of preionization by external agency is considered and it is reported that, under optimal conditions, practically 100% of the electrical pump energy can be converted into the

  9. Laser-Induced Fluorescence Studies of the Jet-Cooled Carbon Dioxide and Nitrous Oxide Cations

    Microsoft Academic Search

    Mohammed A. Gharaibeh; Dennis J. Clouthier

    2010-01-01

    Laser-induced fluorescence (LIF) and single vibronic level (SVL) emission spectra of the ~A^2Pi_u - ~X^2Pi_g} system of 12CO_2^+ and 13CO_2^+ and the ~A^2Sigma^+ - ~X^2Pi system of N_2O^+ have been observed. The cations were produced in a pulsed electric discharge jet with a precursor mixture of the corresponding neutral molecule in high pressure argon. The LIF bands of 12CO_2^+ and

  10. Carbon Dioxide Absorption Heat Pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor)

    2002-01-01

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

  11. Oxygen(¹. sigma. \\/sub g\\/\\/sup +\\/) energy transfer carbon dioxide laser

    Microsoft Academic Search

    G. D. Downey; D. W. Robinson

    1976-01-01

    Flash photolysis of mixtures of O\\/CO\\/O in a laser cavity produces oscillation on the P(14)-P(20) lines of the 10.6-..mu.. band of CO. All the experimental observations are consistent with the pumping scheme: O + h..nu.. ..-->.. O(¹D) + O(¹..delta..\\/sub g\\/) (1); O(¹D) + O(³..sigma..\\/sub g\\/⁻) ..-->.. O(³P) + O(¹..sigma..\\/sub g\\/\\/sup +\\/) (2); O(¹..sigma..\\/sub g\\/\\/sup +\\/) + CO(000) ..-->.. O(¹..delta..\\/sub g\\/)

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

    E-print Network

    VAPOR + 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) and their binary mixtures (between 348 and 393 K). The properties of supercritical carbon dioxide were determined

  13. Trends in laser material processing for cutting, welding, and metal deposition using carbon dioxide, direct diode, and fiber lasers

    NASA Astrophysics Data System (ADS)

    Penn, Wayne

    2005-03-01

    New laser technologies challenge the established laser workhorses. The strengths and weaknesses of some of the major players for material processing will be covered. Applications and comparisons will be covered with results in the areas of cutting, welding, and metal deposition. Capability, trends and performance needs for the future will be included for industrial applications.

  14. 2, 18491865, 2005 Carbon dioxide in

    E-print Network

    Paris-Sud XI, Universit de

    BGD 2, 18491865, 2005 Carbon dioxide in southern Poland L. Chmura et al. Title Page Abstract is licensed under a Creative Commons License. 1849 #12;BGD 2, 18491865, 2005 Carbon dioxide in southern urban environment with numerous local sources of carbon dioxide. Despite of relative proximity of those

  15. 7Carbon Dioxide Increases The Keeling Curve,

    E-print Network

    7Carbon Dioxide Increases The Keeling Curve, shown to the left, shows the variation in concentration of atmospheric carbon dioxide since 1958-1974. It is based on continuous measurements taken of rapidly increasing carbon dioxide levels in the atmosphere. Additional measurements by scientists working

  16. 21 CFR 184.1240 - Carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...3 2014-04-01 2014-04-01 false Carbon dioxide. 184.1240 Section 184.1240 Food and...Specific Substances Affirmed as GRAS 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2 , CAS Reg....

  17. SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW

    E-print Network

    Santos, Juan

    SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW J. E. Santos1 1 Department of Mathematics, Purdue University, USA Purdue University, March 1rst, 2013 SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW p. #12 (North Sea). SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW p. #12;Introduction. II CO2 is separated

  18. SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW

    E-print Network

    Santos, Juan

    SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW J. E. Santos1, G. B. Savioli2, J. M. Carcione3, De, Argentina SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW p. #12;Introduction. I Storage of CO2). SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW p. #12;Introduction. II CO2 is separated from natural

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

    Microsoft Academic Search

    Brian James Kirby

    2001-01-01

    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

  20. Modelling Sublimation of Carbon Dioxide

    ERIC Educational Resources Information Center

    Winkel, Brian

    2012-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Kirby, Brian James

    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.

  2. Comparative histologic study of alterations in rat skeletal muscles due to carbon dioxide laser with varying power but constant energy

    NASA Astrophysics Data System (ADS)

    Nicola, Ester M. D.; Coutinho, Adriana A.; Metze, Konradin; Nicola, Jorge H.

    1998-01-01

    The aim of our study was to compare biolgic effects such as tissue damage and regeneration in rat skeletal muscle after CO2 laser application with pulses of constant energy density, but with varying power and exposure time. We used three different laser conditions: 20 W by 0.5 s, 10 W by 1.0 s and 5.0 W by 2.0 s, all having the same energy density (10 joules in a constant area). The animals were sacrificed immediately after laser application, and after 1, 4, 7, 15 and 21 days. Tissue damage produced by the CO2 laser with high power provokes more profound craters with less tissue damage at the margins. As shown by lesser tissue carbonization, fewer foreign body giant cell granulomas and less tissue fibrosis and, on the other hand, an accelerated regeneration of muscle tissue.

  3. Carbon Dioxide: Friend or Foe?

    NASA Astrophysics Data System (ADS)

    Muller, C.

    Carbon Dioxide: Friend or Foe is a short rnonograph on the so-called carbon dioxide greenhouse effect. The author challenges the established view that the present CO2 increase would, in the long term, lead to a global ground temperature increase. S. B. Idso, from four sets of observations, has deduced that the temperature response to an increased received energy at the ground should be less than or equal to 0.113 K (W/m2). If this result is combined with the 2.28 W/m2 of increased radiation expected from CO2 doubling, he finds a temperature increase of 0.26 K, which cannot be distinguished form the natural temperature fluctuation. This conclusion is in disagreement with virtually all the current mathematical models that predict a ground temperature response of an order of magnitude or more higher.

  4. Carbon Dioxide Removal via Passive Thermal Approaches

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  5. Carbon dioxide and climate

    Microsoft Academic Search

    Gregg Marland; Ralph M. Rotty

    1979-01-01

    During the years 19751978 concern over the increase of CO2 in the atmosphere expanded from the laboratory into the public policy arena. This was a period during which a profusion of international symposia, technical papers, and public-policy-oriented discussions drew wide attention to the potential dangers of unchecked growth of atmospheric CO2 and man's alterations of the global carbon cycle. At

  6. 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.

  7. Optimize carbon dioxide sequestration, enhance oil recovery

    E-print Network

    - 1 - Optimize carbon dioxide sequestration, enhance oil recovery January 8, 2014 Los Alamos simulation to optimize carbon dioxide (CO2) sequestration and enhance oil recovery (CO2-EOR) based on known production. Due to carbon capture and storage technology advances, prolonged high oil prices

  8. Solubility of Carbon Dioxide in Water.

    ERIC Educational Resources Information Center

    Bush, Pat; And Others

    1992-01-01

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

  9. 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.

  10. Climate models should include carbon dioxide increases

    NSDL National Science Digital Library

    Narisma et al.

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

  11. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... false Carbon monoxide and carbon dioxide analyzer specifications. 86...316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made...

  12. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... false Carbon monoxide and carbon dioxide analyzer specifications. 86...316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made...

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

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... false Carbon monoxide and carbon dioxide analyzer specifications. 86...316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made...

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

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... false Carbon monoxide and carbon dioxide analyzer specifications. 86...316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made...

  15. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2013-07-01 true Carbon dioxide analyzer calibration. 89...Test Equipment Provisions 89.322 Carbon dioxide analyzer calibration. ...and bi-monthly thereafter, the NDIR carbon dioxide analyzer shall be...

  16. 46 CFR 131.817 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...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...

  17. 46 CFR 108.431 - Carbon dioxide systems: General.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Carbon dioxide systems: General. 108.431...EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems 108.431 Carbon dioxide systems: General. (a)...

  18. 40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration. 86...Test Procedures 86.124-78 Carbon dioxide analyzer calibration. Prior...service and monthly thereafter the NDIR carbon dioxide analyzer shall be...

  19. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 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...

  20. 9 CFR 313.5 - Chemical; carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 false Chemical; carbon dioxide. 313.5 Section 313...LIVESTOCK 313.5 Chemical; carbon dioxide. The slaughtering of sheep, calves and swine with the use of carbon dioxide gas and the handling...

  1. 46 CFR 131.817 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 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...

  2. 46 CFR 78.47-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...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...

  3. 40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration. 86...Exhaust Test Procedures 86.1324-84 Carbon dioxide analyzer calibration. Prior...service and monthly thereafter, the NDIR carbon dioxide analyzer shall be calibrated...

  4. 46 CFR 196.37-8 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 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...

  5. 46 CFR 108.626 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...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...

  6. 46 CFR 193.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...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)...

  7. 40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration. 86...Test Procedures 86.524-78 Carbon dioxide analyzer calibration. (a...service and monthly thereafter the NDIR carbon dioxide analyzer shall be...

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 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...

  9. 46 CFR 78.47-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 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...

  10. 21 CFR 868.1400 - Carbon dioxide gas analyzer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Carbon dioxide gas analyzer. 868.1400 Section...DEVICES Diagnostic Devices 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...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...

  12. 40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Carbon dioxide analyzer calibration. 86...Test Procedures 86.524-78 Carbon dioxide analyzer calibration. (a...service and monthly thereafter the NDIR carbon dioxide analyzer shall be...

  13. 40 CFR 91.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  14. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  15. 46 CFR 196.37-8 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...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...

  16. 40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Carbon dioxide analyzer calibration. 86...Test Procedures 86.124-78 Carbon dioxide analyzer calibration. Prior...service and monthly thereafter the NDIR carbon dioxide analyzer shall be...

  17. 40 CFR 90.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2013-07-01 true Carbon dioxide analyzer calibration. 90...Test Equipment Provisions 90.320 Carbon dioxide analyzer calibration. ...certification test, calibrate the NDIR carbon dioxide analyzer as follows:...

  18. 46 CFR 108.626 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 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...

  19. 46 CFR 169.565 - Fixed carbon dioxide system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 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...

  20. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...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...

  1. 40 CFR 90.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  2. 9 CFR 313.5 - Chemical; carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 false Chemical; carbon dioxide. 313.5 Section 313...LIVESTOCK 313.5 Chemical; carbon dioxide. The slaughtering of sheep, calves and swine with the use of carbon dioxide gas and the handling...

  3. 46 CFR 169.565 - Fixed carbon dioxide system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...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...

  4. 40 CFR 91.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2013-07-01 true Carbon dioxide analyzer calibration. 91...Test Equipment Provisions 91.320 Carbon dioxide analyzer calibration. ...certification test, calibrate the NDIR carbon dioxide analyzer as follows:...

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 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)...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...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)...

  7. 46 CFR 169.732 - Carbon dioxide alarm.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 2010-10-01 2010-10-01 false Carbon dioxide alarm. 169.732 Section 169.732 Shipping...Systems, and Equipment Markings 169.732 Carbon dioxide alarm. Each carbon dioxide alarm must be conspicuously identified:...

  8. 46 CFR 169.732 - Carbon dioxide alarm.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 2011-10-01 2011-10-01 false Carbon dioxide alarm. 169.732 Section 169.732 Shipping...Systems, and Equipment Markings 169.732 Carbon dioxide alarm. Each carbon dioxide alarm must be conspicuously identified:...

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

    SciTech Connect

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

    1985-04-01

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

  10. Carbon dioxide disposal in solid form

    SciTech Connect

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

    1995-12-31

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

  11. Sorption of carbon dioxide onto sodium carbonate

    SciTech Connect

    Sang-Wook Park; Deok-Ho Sung; Byoung-Sik Choi; Kwang-Joong Oh; Kil-Ho Moon [Pusan National University, Busan (Republic of Korea). Division of Chemical Engineering

    2006-07-01

    Sodium carbonate was used as a sorbent to capture CO{sub 2} from a gaseous stream of carbon dioxide, nitrogen, and moisture. The breakthrough data of CO{sub 2} were measured in a fixed bed to observe the reaction kinetics of CO{sub 2}-carbonate reaction. Several models such as the shrinking-core model, the homogeneous model, and the deactivation model in the non-catalytic heterogeneous reaction systems were used to explain the kinetics of reaction among CO{sub 2}, Na{sub 2}CO{sub 3}, and moisture using analysis of the experimental breakthrough data. Good agreement of the deactivation model was obtained with the experimental breakthrough data. The sorption rate constant and the deactivation rate constant were evaluated by analysis of the experimental breakthrough data using a nonlinear least squares technique and described as Arrhenius form.

  12. Trading coalbed methane for carbon dioxide

    SciTech Connect

    Greenberger, L.S.

    1991-08-15

    This article discusses a proposal for reducing methane emissions in coal mining activities and at the same time reducing the burden on utilities to cut carbon dioxide emissions. Emission credits would be issued to mines that recover the methane for use. These credits could then be bought by utilities and exchanged for the right to emit carbon dioxide.

  13. Interglacials, Milankovitch Cycles, and Carbon Dioxide

    E-print Network

    Gerald E. Marsh

    2010-02-11

    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.

  14. Polymer synthesis: Chaining up carbon dioxide

    NASA Astrophysics Data System (ADS)

    Dove, Andrew P.

    2014-04-01

    The development of methods for efficiently using carbon dioxide in synthesis would enable chemists to tap into this abundant resource. Now, an indirect route to the copolymerization of alkenes with carbon dioxide shows how this greenhouse gas may prove useful in the search for new 'green' materials.

  15. Carbon dioxide in northeastern New Mexico

    Microsoft Academic Search

    ROY W. FOSTER; JAMES G. JENSEN

    1972-01-01

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

  16. Carbon Dioxide for pH Control

    SciTech Connect

    Wagonner, R.C.

    2001-08-16

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

  17. DEVELOPMENT AND INTEGRATION OF NEW PROCESSES CONSUMING CARBON DIOXIDE IN

    E-print Network

    Pike, Ralph W.

    DEVELOPMENT AND INTEGRATION OF NEW PROCESSES CONSUMING CARBON DIOXIDE IN MULTI-PLANT CHEMICAL........................................................ 8 C. Carbon Dioxide A Greenhouse Gas................................................ 9 1. Sources

  18. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    SciTech Connect

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

    2001-06-15

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

  19. Model of the kinetic cooling of carbon dioxide gas

    Microsoft Academic Search

    A. N. Vargin; V. V. Gogokhiia; V. K. Koniukhov; A. I. Lukovnikov

    1978-01-01

    Kinetic equations of vibrational relaxation in polyatomic gases are used in a quantitative description of kinetic (laser) cooling in carbon dioxide. At a temperature of 300 K, the vibrational relaxation of an antisymmetric mode is accompanied by the exchange of the vibrational energy of the antisymmetric mode into three quanta of a combined deformation and symmetric mode. Initial conditions corresponded

  20. Homogeneous hydrogenation of carbon dioxide

    SciTech Connect

    Jessop, P.G.; Ikariya, Takao; Noyori, Ryoji [Research Development Corp. of Japan, Toyota (Japan). ERATO Molecular Catalysis Project

    1995-03-01

    Carbon dioxide (CO{sub 2}) is of the greatest interest as a C{sub 1} feedstock because of the vast amounts of carbon which exist in this form and because of the low cost of bulk CO{sub 2}. Currently, toxic carbon monoxide, the main competitor for many processes, is used in industry instead because CO{sub 2} is perceived to be less reactive and its efficient catalytic conversion has remained elusive. Because CO{sub 2} is a highly oxidized, thermodynamically stable compound, its utilization requires reaction with certain high energy substances or electroreductive processes. Catalytic hydrogenation is one of the most promising approaches to CO{sub 2} fixation. Recent research has shown that high catalytic efficiency, yields, and rates of reaction can be obtained from CO{sub 2} with optimum conditions and catalysts. This review will describe the simplest and most studied reactions of CO{sub 2}: the catalytic reactions with H{sub 2} in the presence or absence of other reactive species. The mechanisms of homogeneously catalyzed reactions will be emphasized. Subjects which will not be covered, aside from brief mentions, include stoichiometric reactions of CO{sub 2} with complexes, the reverse water gas shift reaction, hydrosilylation, and electrochemical or photochemical reductions of CO{sub 2}. 132 refs.

  1. Microfluidic studies of carbon dioxide.

    PubMed

    Abolhasani, Milad; Gnther, Axel; Kumacheva, Eugenia

    2014-07-28

    Carbon dioxide (CO2) sequestration, storage and recycling will greatly benefit from comprehensive studies of physical and chemical gas-liquid processes involving CO2. Over the past five years, microfluidics emerged as a valuable tool in CO2-related research, due to superior mass and heat transfer, reduced axial dispersion, well-defined gas-liquid interfacial areas and the ability to vary reagent concentrations in a high-throughput manner. This Minireview highlights recent progress in microfluidic studies of CO2-related processes, including dissolution of CO2 in physical solvents, CO2 reactions, the utilization of CO2 in materials science, and the use of supercritical CO2 as a "green" solvent. PMID:24961230

  2. Adipose-derived stem cells cooperate with fractional carbon dioxide laser in antagonizing photoaging: a potential role of Wnt and ?-catenin signaling

    PubMed Central

    2014-01-01

    Background It is well established that adipose-derived stem cells (ADSCs) produce and secrete cytokines/growth factors that antagonize UV-induced photoaging of skin. However, the exact molecular basis underlying the anti-photoaging effects exerted by ADSCs is not well understood, and whether ADSCs cooperate with fractional carbon dioxide (CO2) laser to facilitate photoaging skin healing process has not been explored. Here, we investigated the impacts of ADSCs on photoaging in a photoaging animal model, its associated mechanisms, and its functional cooperation with fractional CO2 laser in treatment of photoaging skin. Results We showed that ADSCs improved dermal thickness and activated the proliferation of dermal fibroblast. We further demonstrated that the combined treatment of ADSCs and fractional CO2 laser, the latter which is often used to resurface skin and treat wrinkles, had more beneficial effects on the photoaging skin compared with each individual treatment. In our prepared HDF photoaging model, flow cytometry showed that, after adipose derived stem cells conditioned medium (ADSC-CM) co-cultured HDF photoaging model, the cell proliferation rate is higher than UVB irradiation induced HDF modeling (p?laser treatment. And the expression of wnt3a and ?-catenin has the positive correlation with photoaging related protein TGF-?2 and COLI. We also verified these protein expressions in tissue level. In addition, after injected SFRP2 into ADSC-CM co-cultured HDF photoaging model, wnt3a inhibitor, compared with un-intervened group, wnt3a, ?-catenin protein level significantly decreased. Conclusion Both ADSCs and fractional CO2 laser improved photoaging skin at least partially via targeting dermal fibroblast activity which was increased in photoaging skin. The combinatorial use of ADSCs and fractional CO2 laser synergistically improved the healing process of photoaging skin. Thus, we provide a strong rationale for a combined use of ADSCs and fractional CO2 laser in treatment of photoaging skin in clinic in the future. Moreover, we provided evidence that the Wnt/?-catenin signaling pathway may contribute to the activation of dermal fibroblast by the transplantation of ADSCs in both vitro and vivo experiment. PMID:24917925

  3. Carbon dioxide emission scenarios: limitations of the fossil fuel resource

    Microsoft Academic Search

    Christopher Vernon; Erica Thompson; Sarah Cornell

    2011-01-01

    Contemporary increases in atmospheric carbon dioxide concentration are in large part the result of anthropogenic carbon dioxide emissions from fossil fuel combustion. Scenario analysis is commonly used to generate projections of future carbon dioxide emissions, the resulting atmospheric concentrations and climate impact. In most scenario modelling published to date, carbon dioxide emission scenarios are based on demand-side (socioeconomic and technology)

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

    Microsoft Academic Search

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

    1980-01-01

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

  5. Testing carbon sequestration site monitor instruments using a controlled carbon dioxide release facility

    Microsoft Academic Search

    Seth D. Humphries; Amin R. Nehrir; Charlie J. Keith; Kevin S. Repasky; Laura M. Dobeck; John L. Carlsten; Lee H. Spangler

    2008-01-01

    Two laser-based instruments for carbon sequestration site monitoring have been developed and tested at a controlled carbon dioxide CO2 release facility. The first instrument uses a temperature tunable distributed feedback (DFB) diode laser capable of accessing the 2.0027-2.0042 m spectral region that contains three CO2 absorption lines and is used for aboveground atmospheric CO2 concentration mea- surements. The second instrument

  6. 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...

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

    DOEpatents

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

    2004-06-08

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

  8. Carbon Dioxide Emission Factors for Coal

    EIA Publications

    1994-01-01

    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.

  9. Regulating carbon dioxide capture and storage

    E-print Network

    De Figueiredo, Mark A.

    2007-01-01

    This essay examines several legal, regulatory and organizational issues that need to be addressed to create an effective regulatory regime for carbon dioxide capture and storage ("CCS"). Legal, regulatory, and organizational ...

  10. Displacement of crude oil by carbon dioxide

    E-print Network

    Omole, Olusegun

    1980-01-01

    DISPLACEMENT OF CRUDE OIL BY CARBON DIOXIDE A Thesis by OLUSEGUN OMOLE Submitted to the Graduate College of Texas ASM University in part';al fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1980 Major Subject...: Petroleum Engineering DISPLACEMENT OF CRUDE OIL BY CARBON DIOXIDE A Thesis by OLUSEGUN OMOLE Approved as to style and content by: hairman of Committee / (Member (Member (Member (Hea o Depart ent December 1980 ABSTRACT Displacement of Crude Oil...

  11. The Limiting Carbon Dioxide Concentration for Photosynthesis

    Microsoft Academic Search

    Dale N. Moss

    1962-01-01

    MANY reports1-5 indicate that plants in a closed system will reduce the concentration of carbon dioxide in the air to a minimum value between 50 and 100 p.p.m. Gabrielsen2 postulates ``there exists a threshold value for carbon dioxide in photosynthesis, which for elder leaves is about 0.0090 volume per cent. Below the threshold no assimilation takes place. Thus it seems

  12. Education, Convergence and Carbon Dioxide Growth per Capita

    E-print Network

    Paris-Sud XI, Universit de

    65 Education, Convergence and Carbon Dioxide Growth per Capita Kinda Somlanare Romuald Abstract dioxide emissions around the world, and that education is not a factor in carbon dioxide emissions growth, there is no convergence, and that education is not a factor in carbon dioxide growth. In developed countries, we find

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

    PubMed Central

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

    2013-01-01

    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

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

    Microsoft Academic Search

    E. S. McKee; I. M. Pritts

    1981-01-01

    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), carbon monoxide (CO), carbon dioxide (CO), hydrogen sulfide (HS), nitrogen dioxide

  15. Monitoring annealing via carbon dioxide laser heating of defect populations in fused silica surfaces using photoluminescence microscopy

    SciTech Connect

    Raman, R N; Matthews, M J; Adams, J J; Demos, S G

    2010-02-01

    Photoluminescence (PL) microscopy and spectroscopy under 266 nm and 355 nm laser excitation are explored as a means of monitoring defect populations in laser-modified sites on the surface of fused silica and their subsequent response to heating to different temperatures via exposure to a CO{sub 2} laser beam. Laser-induced temperature changes were estimated using an analytic solution to the heat flow equation and compared to changes in the PL emission intensity. The results indicate that the defect concentrations decrease significantly with increasing CO{sub 2} laser exposure and are nearly eliminated when the peak surface temperature exceeds the softening point of fused silica ({approx}1900K), suggesting that this method might be suitable for in situ monitoring of repair of defective sites in fused silica optical components.

  16. Carbon Dioxide- Where Does it All Go?

    NSDL National Science Digital Library

    In this problem set, learners will use a diagram of carbon fluxes, which shows the sources that contribute to current atmospheric carbon dioxide levels, to answer a series of questions. Answer key is provided. This problem is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

  17. Hydroelectric Reservoirs -the Carbon Dioxide and Methane

    E-print Network

    Fischlin, Andreas

    Hydroelectric Reservoirs - the Carbon Dioxide and Methane Emissions of a "Carbon Free" Energy an overview on the greenhouse gas production of hydroelectric reservoirs. The goals are to point out the main how big the greenhouse gas emissions from hydroelectric reservoirs are compared to thermo-power plants

  18. 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.

  19. Reaction of yttrium polonides with carbon dioxide

    SciTech Connect

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

    1986-09-01

    It has been proved that heating of yttrium and tantalum in carbon dioxide to 500 and 800/sup 0/C alters the gas phase composition, causing formation of carbon monoxide and reduction of oxygen content. A study of the thermal stability of yttrium polonides in carbon dioxide showed that yttrium sesqui- and monopolonides decompose at 400-430/sup 0/C. The temperature dependence of the vapor pressure of polonium obtained upon decomposition of the referred polonides has been determined in a carbon dioxide environment radiotensometrically. The enthalpy of the process calculated from this dependence is close to the enthalpy of vaporization of elemental polonium in vacuo. The mechanism of the reactions has been suggested.

  20. Reaction of titanium polonides with carbon dioxide

    SciTech Connect

    Abakumov, A.S.; Malyshev, M.L.; Reznikova, N.F.

    1987-05-01

    It has been ascertained that heating titanium and tantalum in carbon dioxide to temperatures of 500 or 800/sup 0/C alters the composition of the gas phase, causing the advent of carbon monoxide and lowering the oxygen content. Investigation of the thermal stability of titanium polonides in a carbon dioxide medium has shown that titanium mono- and hemipolonides are decomposed at temperatures below 350/sup 0/C. The temperature dependence of the vapor pressure of polonium produced in the decomposition of these polonides in a carbon dioxide medium have been determined by a radiotensimetric method. The enthalpy of the process, calculated from this relationship, is close to the enthalpy of vaporization of elementary polonium in vacuo.

  1. Turning carbon dioxide into fuel.

    PubMed

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

    2010-07-28

    Our present dependence on fossil fuels means that, as our demand for energy inevitably increases, so do emissions of greenhouse gases, most notably carbon dioxide (CO2). To avoid the obvious consequences on climate change, the concentration of such greenhouse gases in the atmosphere must be stabilized. But, as populations grow and economies develop, future demands now ensure that energy will be one of the defining issues of this century. This unique set of (coupled) challenges also means that science and engineering have a unique opportunity-and a burgeoning challenge-to apply their understanding to provide sustainable energy solutions. Integrated carbon capture and subsequent sequestration is generally advanced as the most promising option to tackle greenhouse gases in the short to medium term. Here, we provide a brief overview of an alternative mid- to long-term option, namely, the capture and conversion of CO2, to produce sustainable, synthetic hydrocarbon or carbonaceous fuels, most notably for transportation purposes. Basically, the approach centres on the concept of the large-scale re-use of CO2 released by human activity to produce synthetic fuels, and how this challenging approach could assume an important role in tackling the issue of global CO2 emissions. We highlight three possible strategies involving CO2 conversion by physico-chemical approaches: sustainable (or renewable) synthetic methanol, syngas production derived from flue gases from coal-, gas- or oil-fired electric power stations, and photochemical production of synthetic fuels. The use of CO2 to synthesize commodity chemicals is covered elsewhere (Arakawa et al. 2001 Chem. Rev. 101, 953-996); this review is focused on the possibilities for the conversion of CO2 to fuels. Although these three prototypical areas differ in their ultimate applications, the underpinning thermodynamic considerations centre on the conversion-and hence the utilization-of CO2. Here, we hope to illustrate that advances in the science and engineering of materials are critical for these new energy technologies, and specific examples are given for all three examples. With sufficient advances, and institutional and political support, such scientific and technological innovations could help to regulate/stabilize the CO2 levels in the atmosphere and thereby extend the use of fossil-fuel-derived feedstocks. PMID:20566515

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

    PubMed Central

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

    2014-01-01

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

  3. Calculation of weld metal composition change in high-power conduction mode carbon dioxide laser-welded stainless steels

    Microsoft Academic Search

    K. Mundra; T. Debroy

    1993-01-01

    The use of high-power density laser beam for welding of many important alloys often leads to appreciable changes in the composition\\u000a and properties of the weld metal. The main difficulties in the estimation of laser-induced vaporization rates and the resulting\\u000a composition changes are the determination of the vapor condensation rates and the incorporation of the effect of the welding\\u000a plasma

  4. Global deforestation: contribution to atmospheric carbon dioxide

    Microsoft Academic Search

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

    1983-01-01

    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

  5. Carbon Dioxide Fluxes in the Global Ocean

    Microsoft Academic Search

    Andrew J. Watson; James C. Orr

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

  6. Carbon Dioxide Extraction from Air: Is It An Option?

    SciTech Connect

    Klaus Lackner; Hans-Joachim Ziock; Patrick Grimes

    1999-02-01

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

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

    PubMed

    Menovsky, Tomas; Beek, Johan F

    2003-01-01

    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

  8. A wide angle search technique for a 10.6 micron ladar. [scanning radar using Q switched carbon dioxide laser

    NASA Technical Reports Server (NTRS)

    Levinson, S.; Adelman, S.; Lowrey, D. O.

    1975-01-01

    A ladar (laser radar) sensor designed around a pulsed passively Q-switched CO2 laser, capable of a efficient and rapid scans with a narrow beam over a wide field of view, is considered for surveillance and tracking applications in space. The output is a train of narrow pulses with a controllable pulse repetition rate. A resonant vibrating mirror in back of a classical Gregorian telescope, and a plane pointing mirror in front for beam steering, are used in scanning. Scan pulse sequences are described and illustrated. The 10.6 micron ladar set is under consideration as baseline sensor for various space rendezvous and docking applications.

  9. Do Plants Really Use Carbon Dioxide?

    NSDL National Science Digital Library

    American Educational Products

    1992-01-01

    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 tanksone tank with Elodea and one withoutis 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.

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

    Microsoft Academic Search

    G. J. Fergusson

    1958-01-01

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

  11. Preliminary Study on Pain Reduction of Monosodium Iodoacetate-Induced Knee Osteoarthritis in Rats by Carbon Dioxide Laser Moxibustion

    PubMed Central

    Wu, Fan; Zhang, Ruixing; Shen, Xueyong; Lao, Lixing

    2014-01-01

    In order to study the effects of CO2 laser moxibustion on the pain and inflammatory cytokine expression in the spinal dorsal horn of rats with monosodium iodoacetate- (MIA-) induced knee osteoarthritis (KOA), we designed an experiment by randomly assigning 8 SD rats into 3 groups, namely, a CO2 laser moxibustion group, a sham treatment group, and a blank control group. The treatment group received a laser moxibustion on acupoint Dubi (ST 35; 5?min/treatment, 1 treatment/day) for 8 days, and after treatment, the rats exhibited significantly increased interhindpaw differences compared with their preinduction values. Meanwhile, cytokine microarray analysis showed that one cytokine (TIMP-1) was significantly upregulated and two cytokines (Agrin and MMP-8) were significantly downregulated in treatment group. The present study suggested that CO2 laser moxibustion created certain pain reduction in the rats with MIA-induced KOA and significantly inhibited the expression of most inflammatory cytokines in the ipsilateral spinal dorsal horn. PMID:25013448

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

    Microsoft Academic Search

    M. D. Thomason

    1982-01-01

    Rates for resonant vibrational and rotational energy transfer from the 001 state by CO2 + CO2 collisions were measured. All data were obtained by double resonance spectroscopy with CO2 lasers in a 2.5 meter absorption cell at 700 K. Results for rotation transfer include pumped level relaxation and the response of other 001 levels with delta up to 18. These

  13. Absorption spectroscopic studies of carbon dioxide conversion in a low pressure glow discharge using tunable infrared diode lasers

    Microsoft Academic Search

    F. Hempel; J. Rpcke; F. Miethke; H.-E. Wagner

    2002-01-01

    The time and spatial dependence of the chemical conversion of CO2 to CO were studied in a closed glow discharge reactor (p = 50 Pa, I = 2-30 mA) consisting of a small plasma zone and an extended stationary afterglow. Tunable infrared diode laser absorption spectroscopy has been applied to determine the absolute ground state concentrations of CO and CO2.

  14. Safe and effective one-session fractional skin resurfacing using a carbon dioxide laser device in super-pulse mode: a clinical and histologic study.

    PubMed

    Trelles, Mario A; Shohat, Michael; Urdiales, Fernando

    2011-02-01

    Carbon dioxide (CO(2)) laser ablative fractional resurfacing produces skin damage, with removal of the epidermis and variable portions of the dermis as well as associated residual heating, resulting in new collagen formation and skin tightening. The nonresurfaced epidermis helps tissue to heal rapidly, with short-term postoperative erythema. The results for 40 patients (8 men and 32 women) after a single session of a fractional CO(2) resurfacing mode were studied. The treatments included resurfacing of the full face, periocular upper lip, and residual acne scars. The patients had skin prototypes 2 to 4 and wrinkle degrees 1 to 3. The histologic effects, efficacy, and treatment safety in various clinical conditions and for different phototypes are discussed. The CO(2) laser for fractional treatment is used in super-pulse mode. The beam is split by a lens into several microbeams, and super-pulse repetition is limited by the pulse width. The laser needs a power adaptation to meet the set fluence per microbeam. Laser pulsing can operate repeatedly on the same spot or be moved randomly over the skin, using several passes to achieve a desired residual thermal effect. Low, medium, and high settings are preprogrammed in the device, and they indicate the strength of resurfacing. A single treatment was given with the patient under topical anesthesia. However, the anesthesia was injected on areas of scar tissue. Medium settings (2Hz, 30W, 60mJ) were used, and two passes were made for dark skins and degree 1 wrinkles. High settings (2Hz, 60W, 120mJ) were used, and three passes were made for degree 3 wrinkles and scar tissue. Postoperatively, resurfaced areas were treated with an ointment of gentamycin, Retinol Palmitate, and DL-methionine (Novartis; Farmaceutics, S.A., Barcelona, Spain). Once epithelialization was achieved, antipigment and sun protection agents were recommended. Evaluations were performed 15days and 2months after treatment by both patients and clinicians. Treatment improved wrinkle aspect and scar condition, and no patient reported adverse effects or complications, irrespective of skin type, except for plaques of erythema in areas that received extra laser passes, which were not seen at the 2-month assessment. The results evaluated by clinicians were very much in correlation with those of patients. Immediately after treatment, vaporization was produced by stacked pulses, with clear ablation and collateral heat coagulation. An increased number of random pulses removed more epidermis, and with denser pulses per area, a thermal deposit was noted histologically. At 2months, a thicker, multicelluar epidermis and an evident increase in collagen were observed. Fractional CO(2) laser permits a variety of resurfacing settings that obtain safe, effective skin rejuvenation and correct scar tissue in a single treatment. PMID:20814788

  15. Carbon dioxide opacity of the Venus' atmosphere

    NASA Astrophysics Data System (ADS)

    Snels, Marcel; Stefani, Stefania; Grassi, Davide; Piccioni, Giuseppe; Adriani, Alberto

    2014-11-01

    Venus' atmosphere consists of about 95% of carbon dioxide, which accounts for most of the absorption of the radiation emitted by its hot surface. The large densities and high temperatures of Venus' atmosphere make the absorption much more complex than for low density atmospheres such as Earth or Mars. Available experimental data are at present insufficient and theoretical models inadequate to describe complex absorption line shapes and collision-induced phenomena. Here we present a survey of all absorption and scattering processes which influence the transparency of Venus' atmosphere for what concerns carbon dioxide.

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

    NASA Technical Reports Server (NTRS)

    1964-01-01

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

  17. 40 CFR 86.1524 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Environment 19 2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration. 86.1524 Section 86.1524...Light-Duty Trucks; Idle Test Procedures 86.1524 Carbon dioxide analyzer calibration. (a) The calibration...

  18. 40 CFR 86.1524 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Environment 19 2014-07-01 2014-07-01 false Carbon dioxide analyzer calibration. 86.1524 Section 86.1524...Light-Duty Trucks; Idle Test Procedures 86.1524 Carbon dioxide analyzer calibration. (a) The calibration...

  19. 40 CFR 86.1524 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Environment 19 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration. 86.1524 Section 86.1524...Light-Duty Trucks; Idle Test Procedures 86.1524 Carbon dioxide analyzer calibration. (a) The calibration...

  20. 40 CFR 86.1524 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Environment 20 2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration. 86.1524 Section 86.1524...Light-Duty Trucks; Idle Test Procedures 86.1524 Carbon dioxide analyzer calibration. (a) The calibration...

  1. 40 CFR 86.1524 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Environment 20 2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration. 86.1524 Section 86.1524...Light-Duty Trucks; Idle Test Procedures 86.1524 Carbon dioxide analyzer calibration. (a) The calibration...

  2. International Space Station Carbon Dioxide Removal Assembly Testing

    NASA Technical Reports Server (NTRS)

    Knox, James C.

    2000-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

  5. A methodology for forecasting carbon dioxide flooding performance

    E-print Network

    Marroquin Cabrera, Juan Carlos

    1998-01-01

    A methodology was developed for forecasting carbon dioxide (CO2) flooding performance quickly and reliably. The feasibility of carbon dioxide flooding in the Dollarhide Clearfork "AB" Unit was evaluated using the methodology. This technique is very...

  6. Global deforestation: contribution to atmospheric carbon dioxide

    SciTech Connect

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

    1983-12-09

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

  7. Model-based estimation of the global carbon budget and its uncertainty from carbon dioxide and carbon isotope records

    E-print Network

    Jain, Atul K.

    Model-based estimation of the global carbon budget and its uncertainty from carbon dioxide and the terrestrial biosphere based on carbon dioxide and carbon isotope records, and prior information on model of carbon dioxide and the resulting atmospheric concentration of carbon dioxide determined from the behavior

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

    NASA Astrophysics Data System (ADS)

    Urru, Giovanni; Moretti, Gianfranco

    1998-01-01

    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.

  9. Rapid Vibrational and Rotational Energy Transfer Rates in Heated Carbon-Dioxide Collisions by Double Resonance Laser Spectroscopy

    Microsoft Academic Search

    Michael David Thomason

    1982-01-01

    Rates for resonant vibrational and rotational energy transfer from the 001 state by CO(,2) + CO(,2) collisions have been measured. All data were obtained by double resonance spectroscopy with CO(,2) lasers in a 2.5 meter absorption cell at 700(DEGREES)K. Results for rotation transfer include pumped-level relaxation and the response of other 001 levels with (DELTA)j up to 18. These data

  10. Calculation of weld metal composition change in high-power conduction mode carbon dioxide laser-welded stainless steels

    NASA Astrophysics Data System (ADS)

    Mundra, K.; Debroy, T.

    1993-02-01

    The use of high-power density laser beam for welding of many important alloys often leads to appreciable changes in the composition and properties of the weld metal. The main difficulties in the estimation of laser-induced vaporization rates and the resulting composition changes are the determination of the vapor condensation rates and the incorporation of the effect of the welding plasma in suppressing vaporization rates. In this article, a model is presented to predict the weld metal composition change during laser welding. The velocity and temperature fields in the weld pool are simulated through numerical solution of the Navier-Stokes equation and the equation of conservation of energy. The computed temperature fields are coupled with ve-locity distribution functions of the vapor molecules and the equations of conservation of mass, momentum, and the translational kinetic energy in the gas phase for the calculation of the evap-oration and the condensation rates. Results of carefully controlled physical modeling experi-ments are utilized to include the effect of plasma on the metal vaporization rate. The predicted area of cross section and the rates of vaporization are then used to compute the resulting com-position change. The calculated vaporization rates and the weld metal composition change for the welding of high-manganese 201 stainless steels are found to be in fair agreement with the corresponding experimental results.

  11. Discussion of Refrigeration Cycle Using Carbon Dioxide as Refrigerant

    NASA Astrophysics Data System (ADS)

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

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

  12. U.S. Energy-Related Carbon Dioxide Emissions

    EIA Publications

    2014-01-01

    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.

  13. Tuning Organic Carbon Dioxide Absorbents for Carbonation and Decarbonation

    PubMed Central

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

    2015-01-01

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

  14. Tuning organic carbon dioxide absorbents for carbonation and decarbonation.

    PubMed

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

    2015-01-01

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

  15. Improved analysis of column carbon dioxide and methane data from ground-based Miniaturized Laser Heterodyne Radiometer (Mini-LHR)

    NASA Astrophysics Data System (ADS)

    Wilson, E. L.; Melroy, H.; Ramanathan, A. K.; Mao, J.; Clarke, G.; McLinden, M.; Ott, L. E.; Miller, J. H. H.; Allan, G. R.; Holben, B. N.

    2014-12-01

    We present an improved data analysis for the Mini-LHR column measurements of CO2 and CH4 that includes corrections for refraction through the atmosphere and meteorological conditions. Multi-scan averaging has also been added to compensate for current shot noise limitations and improve instrument sensitivity. Data with the improved analysis will be shown for field measurements at the TCCON site at CalTech (March 2014), Calpoly during COW-Gas (March 2014), at Mauna Loa Observatory (May 2013), and Atwater, CA (February 2013). The Mini-LHR is a miniaturized version of a laser heterodyne radiometer that implements telecommunications lasers and components to produce a significantly reduced size, low-cost instrument. Laser heterodyne radiometry has been used since the 1970s to measure atmospheric gases such as ozone, water vapor, methane, ammonia, chlorine monoxide, and nitrous oxide. The Mini-LHR is passive and uses sunlight as the primary light source to measure absorption of CO2 and CH4 in the infrared. Sunlight is collected with collimation optics mounted to the AERONET sun tracker and superimposed with laser light in a single mode fiber coupler. The signals are mixed in a fast photoreceiver (InGaAs detector), and the RF (radio frequency) beat signal is extracted. Changes in concentration of the trace gas are realized through analyzing changes in the beat frequency amplitude. In addition to the complementary aerosol optical depth measurement, tandem operation with AERONET provides a clear pathway for the mini-LHR to be expanded into a global monitoring network. AERONET has more than 450 instruments worldwide and offers coverage in key arctic regions (not covered by OCO-2) where accelerated warming due to the release of CO2 and CH4 from thawing tundra and permafrost is a concern. A mini-LHR global ground network can also provide an uninterrupted data record that will both bridge gaps in data sets and offer validation for key flight missions such as OCO-2, OCO-3, and ASCENDS. Currently, the only ground global network that routinely measures multiple greenhouse gases in the atmospheric column is TCCON with 18 operational sites worldwide and two in the US. Cost and size of TCCON installations will limit the potential for expansion. We offer a low-cost (<$30K/unit) solution to supplement these measurements.

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

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Still wines containing carbon dioxide. 26.222 Section 26.222... 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

  17. 27 CFR 26.222 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Still wines containing carbon dioxide. 26.222 Section 26.222... 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

  18. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Still wines containing carbon dioxide. 26.52 Section 26.52...Rico 26.52 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

  19. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Still wines containing carbon dioxide. 26.52 Section 26.52...Rico 26.52 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

  20. Thermodynamic Promotion of Carbon Dioxide Clathrate Hydrate Formation by

    E-print Network

    Paris-Sud XI, Universit de

    Thermodynamic Promotion of Carbon Dioxide Clathrate Hydrate Formation by Tetrahydrofuran, Cyclopentane;______________________________________________________________________ ____________________________________________________________________________________ 2 Abstract Gas clathrate hydrate dissociation pressures are reported for mixtures of carbon dioxide) equilibrium data are presented for the ternary system of water-cyclopentane-carbon dioxide at temperatures

  1. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section...Than Class 1 and Class 7 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered...

  2. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Carbon dioxide record. 24.319 Section 24.319...WINE Records and Reports 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a...

  3. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Carbon dioxide record. 24.319 Section 24.319...WINE Records and Reports 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a...

  4. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section...Than Class 1 and Class 7 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered...

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

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section...Than Class 1 and Class 7 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered...

  6. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section...Than Class 1 and Class 7 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered...

  7. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  8. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section...Than Class 1 and Class 7 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered...

  9. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Carbon dioxide record. 24.319 Section 24.319...WINE Records and Reports 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a...

  10. Thermal Infrared Radiation and Carbon Dioxide in the Atmosphere

    E-print Network

    Olver, Peter

    Thermal Infrared Radiation and Carbon Dioxide in the Atmosphere Bill Satzer 3M Company #12;Outline,840 Oxygen (O2) 209,460 Argon (Ar) 9340 Carbon dioxide (CO2) 394 Methane (CH4) 1.79 Ozone (O3) 0 wavelength of interest is about 400 times the size of a carbon dioxide molecule. Interaction is via

  11. Electrostatic Stabilization of Colloids in Carbon Dioxide: Electrophoresis and Dielectrophoresis

    E-print Network

    Electrostatic Stabilization of Colloids in Carbon Dioxide: Electrophoresis and Dielectrophoresis in supercritical fluid carbon dioxide (scCO2). Herein we demonstrate that colloids may also be stabilized in CO2 the behavior of steric stabilization in compressed supercritical fluids1-3 including carbon dioxide,4

  12. Thermal Properties of Supercritical Carbon Dioxide by Monte Carlo Simulations

    E-print Network

    Lisal, Martin

    Thermal Properties of Supercritical Carbon Dioxide by Monte Carlo Simulations C.M. COLINAa,b, *, C and speed of sound for carbon dioxide (CO2) in the supercritical region, using the fluctuation method based: Fluctuations; Carbon dioxide; 2CLJQ; JouleThomson coefficient; Speed of sound INTRODUCTION Simulation methods

  13. Chukwuemeka I. Okoye Carbon Dioxide Solubility and Absorption Rate in

    E-print Network

    Rochelle, Gary T.

    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

  14. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  15. World Energy Consumption and Carbon Dioxide Emissions: 1950 2050

    E-print Network

    . Stoker, andRuth A. Judson* Emissions of carbon dioxide from combustion of fossil fuels, which mayWorld Energy Consumption and Carbon Dioxide Emissions: 1950 2050 Richard Schmalensee, Thomas M-U" relation with a within- sample peak between carbon dioxide emissions (and energy use) per capita and per

  16. Estimated Carbon Dioxide Emissions in 2008: United States

    Microsoft Academic Search

    C A Smith; A J Simon; R D Belles

    2011-01-01

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

  17. 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 formation rate is fast enough to capture carbon dioxide by dynamic separation, undiminished by the presence

  18. Continuous measurements of nitrous oxide, carbon monoxide, methane and carbon dioxide in the surface ocean with novel laser-absorption analysers

    NASA Astrophysics Data System (ADS)

    Kaiser, Jan; Grefe, Imke; Wager, Natalie; Bakker, Dorothee C. E.; Lee, Gareth A.

    2013-04-01

    In recent years, improvements in spectroscopic technology have revolutionised atmospheric trace gas research. In particular, cavity-based optical absorption analysers allow determination of gas concentrations with high frequency, repeatability, reproducibility and long-term stability. These qualities make them particularly suitable for autonomous measurements on voluntary observing ships (VOS). Here, we present results from three of the first deployments of such analysers on research ships, as a first step towards VOS installations. Los Gatos off-axis ICOS (Integrated Cavity Output Spectroscopy) analysers were used to measure nitrous oxide (N2O), carbon monoxide (CO), methane (CH4) and carbon dioxide (CO2) mixing ratios in ocean surface water during research cruises in 2010, 2011 and 2012. The analysers were coupled to an equilibrator fed by the scientific seawater supply in the ship's laboratories. The equilibrator measurements were alternated with regular measurements of marine air and calibrated standard gases. Short-term precision for 10 s-average N2O mole fractions at an acquisition rate of 1 Hz was better than 0.2 nmol mol-1. The same value was achieved for duplicate measurements of a standard gas analysed within 1 hour of each other. The response time to concentration changes in water was 142-203 s, depending on the headspace flow rate. During the first deployment on the AMT20 cruise (Atlantic Meridional Transect, Southampton to Punta Arenas, 12 October to 25 November 2010), we unexpectedly found the subtropical gyres to be slightly undersaturated in N2O, implying that this region acted as a sink for this greenhouse gas. In contrast, the equatorial region was supersaturated and a source of nitrous oxide to the atmosphere. Mean sea-to-air fluxes were overall small and ranged between -1.6 and 0.11 ?mol m-2 d-1 (negative fluxes imply an net uptake by the ocean). Despite the good short-term repeatability, significant calibration drift occurred between the six-hourly calibration intervals. We have therefore repeated the observations during the AMT22 cruise (Southampton to Punta Arenas, 10 October to 24 November 2012) and will present the results together with the 2010 data. The second deployment during the D366 Round Britain ocean acidification cruise (6 June to 9 July 2011) showed virtually no day-to-day drift, based on the calibration gases and marine air analyses. Preliminary analyses of the data show that CH4 and N2O were supersaturated in the Skagerrak region, presumably due to the influence of Baltic Sea water, and in coastal areas. Phytoplankton blooms show evidence of CO2 draw-down. CO is extremely supersaturated (up to 50 times), which can be attributed to photochemical breakdown of dissolved organic carbon compounds. For the more recent deployments, a CO2/CH4 and an N2O/CO analyser were successfully operated in series, off of a single equilibrator feed. No leaks or other problems occurred during these deployments, which shows that such a configuration would be ideal for VOS installations as part of the ICOS observational network.

  19. Potassium intercalation of carbon onions opened by carbon dioxide treatment

    Microsoft Academic Search

    Yu. V. Butenko; Amit K. Chakraborty; N. Peltekis; S. Krishnamurthy; V. R. Dhanak; M. R. C. Hunt; L. iller

    2008-01-01

    The potassium intercalation of onion-like carbon (OLC) samples consisting of aggregates of carbon onions is studied with photoemission spectroscopy. OLC samples were initially prepared by annealing nanodiamonds (320nm in diameter) at 1800K in vacuum. The resulting OLC consists of closed fullerene-like shells. The closed OLC was subsequently treated with carbon dioxide at 1020K in order to open the carbon shells

  20. Carbon dioxide emission from european estuaries

    PubMed

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

    1998-10-16

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

  1. The Swedish carbon dioxide tax: effects on biofuel use and carbon dioxide emissions

    Microsoft Academic Search

    Folke Bohlin

    1998-01-01

    The Swedish carbon dioxide tax was introduced in 1991, by adjusting the existing energy taxation to consider the carbon load of fuels. The tax was initially set at a general level of US $13311The exchange rate used in this paper is US $1=7.5 SEK (Swedish krona) per ton carbon (tc). It was differentiated in 1993, with the result that industry

  2. Modelling carbon dioxide accumulation at Sleipner: Implications for underground carbon storage

    E-print Network

    Huppert, Herbert

    Modelling carbon dioxide accumulation at Sleipner: Implications for underground carbon storage Mike dioxide; Viscous flow; Gravity flow 1. Introduction Disposal of carbon dioxide in geological reservoirs;questions about the environmental benefits of this process concern the fate of the carbon dioxide over

  3. Paleoclimatic warming increased carbon dioxide concentrations

    Microsoft Academic Search

    D. M. Lemoine

    2010-01-01

    If climate-carbon feedbacks are positive, then warming causes changes in carbon dioxide (CO2) sources and sinks that increase CO2 concentrations and create further warming. Previous work using paleoclimatic reconstructions has not disentangled the causal effect of interest from the effects of reverse causality and autocorrelation. The response of CO2 to variations in orbital forcing over the past 800,000 years suggests

  4. Large growth seen for carbon dioxide pipelines

    Microsoft Academic Search

    Boecker

    1984-01-01

    A new and fast growing potential market for the pipeline industry is for lines for transporting carbon dioxide which has proven to be an excellent and economic method of enhanced recovery in older oil fields. The technical feasibility of such pipelines has been established with two large systems completed in the US last year and many more now in the

  5. Carbon Dioxide Capture, Transport and Storage

    Microsoft Academic Search

    Li He-nan; Li Fang-qin; Ren Jian-xing; Hao Zhi-wu

    2010-01-01

    It is known to all that potential global climate change has a great deal to do with anthropogenic emissions of CO2. The carbon dioxide emissions from the exhaust gases of the fossil fuel-fired power plants account for about a third of global CO2 emissions and are increasing in the last decades. At this context, this work presents a survey on

  6. Carbon dioxide storage potential of shales

    Microsoft Academic Search

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

    2008-01-01

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

  7. 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.

  8. The Emission Spectrum of Carbon Dioxide

    Microsoft Academic Search

    H. D. Smyth

    1931-01-01

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

  9. Acid sorption regeneration process using carbon dioxide

    DOEpatents

    King, C. Judson (Kensington, CA); Husson, Scott M. (Anderson, SC)

    2001-01-01

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

  10. 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.

  11. Ocean Acidification: The Other Carbon Dioxide Problem

    NSDL National Science Digital Library

    NOAA

    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.

  12. Carbon dioxide emissions of Antarctic tourism

    Microsoft Academic Search

    R. Farreny; J. Oliver-Sol; M. A. J. Lamers; B. Amelung; X. Gabarrell; J. Rieradevall; M. Boada; J. Benayas

    2011-01-01

    The increase of tourism to the Antarctic continent may entail not only local but also global environmental impacts. These latter impacts, which are mainly caused by transport, have been generally ignored. As a result, there is a lack of data on the global impacts of Antarctic tourism in terms of energy consumption and carbon dioxide emissions. This paper presents and

  13. Recent Events: a Perspective on Carbon Dioxide

    NSDL National Science Digital Library

    2012-08-03

    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.

  14. Synthetic fuels, carbon dioxide and climate

    Microsoft Academic Search

    Alex R. Sapre; John R. Hummel; Ruth A. Reck

    1982-01-01

    The observed increase in atmospheric carbon dioxide (CO2) has been attributed to the use of fossil fuels. There is concern that the generation and use of synthetic fuels derived from oil shale and coal will accelerate the increase of CO2.Depending on the source, 39 or 72 percent more CO2 would be produced per unit of energy if synthetic fuels were

  15. Synthetic fuels, carbon dioxide and climate

    Microsoft Academic Search

    Alex R. Sapre; John R. Hummel; Ruth A. Reck

    1982-01-01

    The observed increase in atmospheric carbon dioxide (CO2) has been attributed to the use of fossil fuels. There is concern that the generation and use of synthetic fuels derived from oil shale and coal will accelerate the increase of CO2. Depending on the source, 39 or 72 percent more CO2 would be produced per unit of energy if synthetic fuels

  16. The Transport Properties of Carbon Dioxide

    Microsoft Academic Search

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

    1990-01-01

    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

  17. Carbon Dioxide Corrosion and Inhibition Studies

    E-print Network

    Petta, Jason

    · Corrosion inhibition very important in the oil industry · Film forming inhibitors containing nitrogen inhibitor for CO2 corrosion · Electrochemistry provides useful ways to study corrosion · At room temperatureCarbon Dioxide Corrosion and Inhibition Studies Kristin Gilida #12;Outline · Background

  18. Sterilization using high-pressure carbon dioxide

    Microsoft Academic Search

    Jian Zhang; Thomas A. Davis; Michael A. Matthews; Michael J. Drews; Martine LaBerge; Yuehuei H. An

    2006-01-01

    Sterility is required for medical devices use in invasive medical procedures, and for some situations in the food industry. Sterilization of heat-sensitive or porous materials or devices, such as endoscopes, porous implants, liquid foodstuff, and liquid medicine, poses a challenge to current technologies. There has been a steady interest in using high-pressure carbon dioxide as a process medium for new

  19. CORROSION OF ALLOY STEELS IN CARBON DIOXIDE

    Microsoft Academic Search

    A. Draycott; B. J. Fox; R. W. Hubery

    1962-01-01

    The corrosion of 1% Cr, 1\\/2% Mo and 2 1\\/4% Cr, 1% Mo steels in carbon ; dioxide was measured within the temperature range 450 to 500 deg C and the ; pressure range 0 to 15 atmospheres. The effects of gas velocity, surface ; preparation, and water content of the gas were also determined. Some results of ; a

  20. Photobiological hydrogen production and carbon dioxide sequestration

    Microsoft Academic Search

    Halil Berberoglu

    2008-01-01

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

  1. CARBON DIOXIDE SEQUESTRATION: WHEN AND HOWMUCH?

    Microsoft Academic Search

    Klaus Keller; Zili Yang; Matt Hall; David F. Bradford

    2003-01-01

    We analyze carbon dioxide (CO sequestration as a strategy to manage future climate change in an optimal economic growth framework. We approach the problem in two ways: first, by using a simple analytical model, and second, by using a numerical optimization model which allows us to explore the problem in a more realistic setting. CO sequestration is not a perfect

  2. Carbon dioxide exchange in a peatland ecosystem

    Microsoft Academic Search

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

    1995-01-01

    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

  3. Spectroscopic carbon dioxide sensor for automotive applications

    Microsoft Academic Search

    Michael Arndt; Maximilian Sauer

    2004-01-01

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

  4. Catalyst cartridge for carbon dioxide reduction unit

    NASA Technical Reports Server (NTRS)

    Holmes, R. F. (inventor)

    1973-01-01

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

  5. Passive Colorimetric Dosimeter Tubes for Ammonia, Carbon Monoxide, Carbon Dioxide, Hydrogen Sulfide, Nitrogen Dioxide and Sulfur Dioxide

    Microsoft Academic Search

    PAUL W. McCONNAUGHEY; ELMER S. McKEE; IRVIN M. PRITTS

    1985-01-01

    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 (NH3), carbon monoxide (CO), carbon dioxide (CO2), hydrogen sulfide (H2S), nitrogen dioxide

  6. The characteristics of time series of carbon dioxide and the relationship between air temperature and carbon dioxide

    Microsoft Academic Search

    M. Hasebe; Y. Suzuki

    2003-01-01

    The increase of the carbon dioxide concentration is the problem that is important for the global warming. Carbon dioxide concentration is gradually increasing for the rapid production activity in agriculture and industry from the latter half in the eighteenth century, in which industrial revolution began in the United Kingdom. The increase of carbon dioxide concentration seems to be mainly caused

  7. Carbon Dioxide Production at Home

    NSDL National Science Digital Library

    2012-08-03

    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.

  8. 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

    Shahabi, Sima; Chiniforush, Nasim; Juybanpoor, Nasrin

    2013-01-01

    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

  9. Mechanistical studies on the formation and destruction of carbon monoxide (CO), carbon dioxide (CO2), and carbon trioxide (CO3)

    E-print Network

    Kaiser, Ralf I.

    Mechanistical studies on the formation and destruction of carbon monoxide (CO), carbon dioxide (CO2 monoxide (CO), carbon dioxide (CO2), and molecular oxygen (O2) with varying carbon-to-oxygen ratios from 1 and destruction pathways of carbon monoxide (CO), carbon dioxide (CO2), and carbon trioxide (CO3

  10. Vibrational Relaxation of Carbon-Dioxide at Lithium FLUORIDE(100) and Aluminum-Oxide Surfaces

    Microsoft Academic Search

    Jeanne Carol Sawicki

    1989-01-01

    The vibrational relaxation of CO_2 (101) at LiF(100) and aluminum oxide surfaces has been investigated by laser induced fluorescence. For these experiments, carbon dioxide is introduced to a cell, where the cell walls form the surface being studied. Laser radiation passing through the cell prepares the (101) state of the molecule, which subsequently collides with the surface and may lose

  11. Untangling the formation of the cyclic carbon trioxide isomer in low temperature carbon dioxide ices

    E-print Network

    Kaiser, Ralf I.

    Untangling the formation of the cyclic carbon trioxide isomer in low temperature carbon dioxide of the cyclic carbon trioxide isomer, CO3(X 1 A1), in carbon-dioxide-rich extraterrestrial ices and in the atmospheres of Earth and Mars were investigated experimentally and theoretically. Carbon dioxide ices were

  12. Analytical relationships between atmospheric carbon dioxide, carbon emissions, and ocean processes

    E-print Network

    Follows, Mick

    Analytical relationships between atmospheric carbon dioxide, carbon emissions, and ocean processes), Analytical relationships between atmospheric carbon dioxide, carbon emissions, and ocean processes, Global Biogeochem. Cycles, 22, GB3030, doi:10.1029/2008GB003184. 1. Introduction [2] Atmospheric carbon dioxide

  13. Modeling the selectivity of activated carbons for efficient separation of hydrogen and carbon dioxide

    E-print Network

    Wu, Jianzhong

    the separation of hydrogen and carbon dioxide via adsorption in activated carbons. In the simulations, both hydrogen and carbon dioxide molecules are modeled as Lennard-Jones spheres, and the activated carbons essentially no preference over the two gases and the selectivity of carbon dioxide relative to hydrogen falls

  14. Carbon dioxide capture from fossil fuel power plants using dolomite

    Microsoft Academic Search

    Drupatie Latchman

    2010-01-01

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

  15. Carbon Dioxide Capture DOI: 10.1002/anie.201000431

    E-print Network

    ] Carbon capture and storage (CCS) schemes embody a group of technologies for the capture of CO2 from power environmental concerns of our age. Carbon capture and storage (CCS) from large point sources such as powerCarbon Dioxide Capture DOI: 10.1002/anie.201000431 Carbon Dioxide Capture: Prospects for New

  16. Carbon Dioxide: Production and Sequestration

    NSDL National Science Digital Library

    2012-08-03

    In this problem set, learners will refer to a satellite image to calculate the rate of carbon sequestration in the areas of bare land and forested lawn shown 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.

  17. Limiting future atmospheric carbon dioxide

    Microsoft Academic Search

    Jorge L. Sarmiento; C. L. Quere; Stephen W. Pacala

    1995-01-01

    We estimate anthropogenic carbon emissions required to stabilize future atmospheric CO at various levels ranging from 350 ppm to 750 ppm. Over the next three centuries, uptake by the ocean and terrestrial biosphere would permit emissions to be 3 to 6 times greater than the total atmospheric increase, with each of them contributing approximately equal amounts. Owing to the nonlinear

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

    SciTech Connect

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

    2000-01-01

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

  19. Carbon Dioxide Absorption from Ansthetic Atmospheres 1

    PubMed Central

    Waters, Ralph M.

    1936-01-01

    A safe and practical technique for the application of carbon dioxide absorption from ansthetic atmospheres is described. It has been found satisfactory in over 20,000 administrations over a period of fifteen years. High-grade soda lime is utilized as the chemical absorbent. Granules are placed in a canister between face mask, and breathing bag. The canister is carefully checked for efficiency by both chemical analyses and physical experiments. Its size, shape and arrangement is shown to be important for safety and maximum efficiency. Detailed techniques are described for the use of various agents. Advantages of carbon dioxide absorption are set forth. The Apna suggested by Guedel is described under the term Controlled Respiration and attention is called to certain of its advantages. ImagesFig. 2Fig. 6Fig. 7Fig. 8 PMID:19990907

  20. Climate Impact of Increasing Atmospheric Carbon Dioxide

    Microsoft Academic Search

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

    1981-01-01

    The global temperature rose by 0.2 degrees C between the middle 1960's and 1980, yielding a warming of 0.4 degrees C in the past century. This temperature increase is consistent with the calculated greenhouse effect due to measured increases of atmospheric carbon dioxide. Variations of volcanic aerosols and possibly solar luminosity appear to be primary causes of observed fluctuations about

  1. Transport of Carbon Dioxide and Radioactive Waste

    Microsoft Academic Search

    Daro R. Gmez; Michael Tyacke

    \\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

  2. World Carbon Dioxide Emissions: 1950-2050

    Microsoft Academic Search

    Richard Schmalensee; Thomas M. Stoker; Ruth A. Judson

    1998-01-01

    Emissions of carbon dioxide from the 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 of 1950-1990. Using the same set of income and population growth assumptions as the Intergovernmental Panel on Climate Change (IPCC), we find that the IPCC's widely used emissions

  3. Carbon dioxide neutral, integrated biofuel facility

    Microsoft Academic Search

    E. E. Powell; G. A. Hill

    2010-01-01

    Algae are efficient biocatalysts for both capture and conversion of carbon dioxide in the environment. In earlier work, we have optimized the ability of Chlorella vulgaris to rapidly capture CO2 from man-made emission sources by varying environmental growth conditions and bioreactor design. Here we demonstrate that a coupled biodiesel-bioethanol facility, using yeast to produce ethanol and photosynthetic algae to produce

  4. Sequestration The Underground Storage of Carbon Dioxide

    Microsoft Academic Search

    Sam Holloway

    Underground storage of industrial quantities of carbon dioxide in porous and permeable reservoir rocks has been taking place\\u000a for the last 11 years at the Sleipner West gas field in the North Sea. A further commercial-scale CO2 storage project has recently begun at In Salah, Algeria, and the Snohvit field, Barents Sea, is to begin injecting CO2 underground in late

  5. Carbon dioxide absorption kinetics in potassium threonate

    Microsoft Academic Search

    A. F. Portugal; F. D. Magalhes; A. Mendes

    2008-01-01

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

  6. Electrochemical carbon dioxide concentrator: Math model

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

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

  7. Carbon dioxide makes heat therapy work

    Microsoft Academic Search

    1987-01-01

    Scientists can now propagate healthy blueberry and raspberry plants from virus-infected stock by treating it with heat and carbon dioxide. Plants are grown at 100°F, which makes them develop faster than the virus can spread. Then cuttings are taken of the new growth - less than an inch long - and grown into full-sized, virus-free plants. But in this race

  8. Improved immobilized carbon dioxide capture sorbents

    Microsoft Academic Search

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

    2005-01-01

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

  9. Carbon dioxide capture with concentrated, aqueous piperazine

    Microsoft Academic Search

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

    2010-01-01

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

  10. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated liquid must comply with the following... (1) All plates for tank, manway nozzle and anchorage...section of the printed volume and at...

  11. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated liquid must comply with the following... (1) All plates for tank, manway nozzle and anchorage...section of the printed volume and at...

  12. Sequestering Naturally Occurring Liquid Carbon Dioxide in the Deep Ocean

    NASA Astrophysics Data System (ADS)

    Capron, M. E.

    2008-12-01

    Liquid carbon dioxide has been found as shallow as 1,500 meters in seafloor ooze. Did the liquid carbon dioxide originate from volcanic activity? Or did bacteria convert organic matter, which started as atmospheric carbon dioxide, into methane and liquid carbon dioxide? At typical ocean temperatures carbon dioxide coming out of solution below 600 meters will be liquid. Therefore, one likely mechanism for generating liquid carbon dioxide in seafloor ooze is the bacterial decomposition of organic matter. This paper examines quantitative and qualitative bacterial decomposition of aquatic biomass, with an emphasis on assessing and demonstrating feasibility. Calculations suggest natural processes sequestering liquid carbon dioxide in the seafloor can be sustainably increased to decrease atmospheric carbon dioxide concentrations. First, algae growing on the ocean surface absorb carbon dioxide. The algae are then gathered into a submerged container. Naturally occurring bacteria will digest the algae producing methane, liquid carbon dioxide, and ammonium. The ammonium can be recycled as a nutrient for growing more algae. Bacterial decomposition continues in dilute solutions with any biomass. The process does not require any particular biomass. Also, concentrating the biomass by removing water is not essential. The buoyancy provided by water allows relatively inexpensive tension fabric structures to contain the dilute algae and decomposition products. Calculations based on algae growth in open ponds and experience with bacterial decomposition at 1 to 5 bar pressures suggest the economics of the associated macro-algae growing and harvesting can favor increasing ocean species diversity.

  13. Fluid Mechanical Modelling of Carbon Dioxide Sequestration

    NASA Astrophysics Data System (ADS)

    Huppert, H. E.

    2007-12-01

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

  14. Carbon Dioxide Aquariums Greenhouse Gas Lesson

    NSDL National Science Digital Library

    Orzali, Joe

    2009-01-01

    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.

  15. Carbon dioxide sensitivity of zeolitic imidazolate frameworks.

    PubMed

    Mottillo, Cristina; Fri?i?, Tomislav

    2014-07-14

    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

  16. A miniature chemiresistor sensor for carbon dioxide.

    PubMed

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

    2015-05-18

    A carpet-like nanostructure of polyaniline (PANI) nanothin film functionalized with poly(ethyleneimine), PEI, was used as a miniature chemiresistor sensor for detection of CO2 at room temperature. Good sensing performance was observed upon exposing the PEI-PANI device to 50-5000ppm CO2 in presence of humidity with negligible interference from ammonia, carbon monoxide, methane and nitrogen dioxide. The sensing mechanism relied on acid-base reaction, CO2 dissolution and amine-catalyzed hydration that yielded carbamates and carbonic acid for a subsequent pH detection. The sensing device showed reliable results in detecting an unknown concentration of CO2 in air. PMID:25910446

  17. Carbon dioxide reduction by the Bosch process

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

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

  18. Carbon dioxide on the early earth.

    PubMed

    Walker, J C

    1985-01-01

    This paper uses arguments of geochemical mass balance to arrive at an estimate of the partial pressure of carbon dioxide in the terrestrial atmosphere very early in earth history. It appears that this partial pressure could have been as large as 10 bars. This large estimate depends on two key considerations. First, volatiles were driven out of the interior of the earth during the course of earth accretion or very shortly thereafter. This early degassing was a consequence of rapid accretion,which gave the young earth a hot and rapidly convecting interior. Second, the early earth lacked extensive, stable continental platforms on which carbon could be stored in the form of carbonate minerals for geologically significant periods of time. In the absence of continental platforms on the early earth, the earth's carbon must have been either in the atmosphere or ocean or in the form of shortlived sedimentary deposits on ephemeral sea floor. PMID:11542014

  19. Carbon dioxide solubility and carbon isotope fractionation in basaltic melt

    SciTech Connect

    Mattey, D.P. (Univ. of London, Egham Hill (United Kingdom) Univ. of Tasmania, Hobart (Australia))

    1991-11-01

    Carbon dioxide solubility and isotope fractionation data for a MORB composition at 1,200-1,400C and 5-20 kbar have been obtained using piston-cylinder apparatus and stepped-heating mass spectrometry. Carbon dioxide solubility in basalt melt at 5, 10 and 20 kbar is 0.15-0.17%, 0.45-0.51%, and 1.49%, respectively. Values for {Delta}Co{sub 2}(vap) - CO 2/3{sup {minus}} (basalt melt), obtained from the difference between the isotopic compositions for coexisting vapor and melt, vary from 1.8% to 2.2%. A review of measured and estimated values for carbon isotope fractionation between CO{sub 2} vapor and carbon dissolved in basic melts shows variation from 1.8% to 4.6%. Results of this study and other considerations favor relatively small equilibrium CO{sub 2} vapor melt fractionation factors around 2%.

  20. Limiting future atmospheric carbon dioxide

    NASA Astrophysics Data System (ADS)

    Sarmiento, Jorge L.; Le QuR, Corinne; Pacala, Stephen W.

    1995-03-01

    We estimate anthropogenic carbon emissions required to stabilize future atmospheric CO2 at various levels ranging from 350 ppm to 750 ppm. Over the next three centuries, uptake by the ocean and terrestrial biosphere would permit emissions to be 3 to 6 times greater than the total atmospheric increase, with each of them contributing approximately equal amounts. Owing to the nonlinear dependence of oceanic and terrestrial biospheric uptake on CO2 concentration, the uptake by these two sinks decreases substantially at higher atmospheric CO2 levels. The uptake also decreases with increased atmospheric CO2 growth rate. All the stabilization scenarios require a substantial future reduction in emissions.

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

    SciTech Connect

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

    2001-07-01

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

  2. Elevated atmospheric carbon dioxide increases soil carbon

    SciTech Connect

    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

    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.

  3. Carbon dioxide-methane mixture adsorption on activated carbon

    Microsoft Academic Search

    V. Goetz; O. Pupier; A. Guillot

    2006-01-01

    In this work, we report new experimental data of pure and binary adsorption equilibria of carbon dioxide and methane on the\\u000a activated carbon RB2 at 273 and 298 K. The pressure range studied were 03.5 MPa for pure gases and 00.1 MPa for mixtures.\\u000a The combination of the generalized Dubinin model to describe the pure CO2 and CH4 isotherms with

  4. Carbon dioxide disposal in carbonate minerals

    Microsoft Academic Search

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

    1995-01-01

    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

  5. Atmospheric Carbon Dioxide and Carbon Reservoir Changes

    Microsoft Academic Search

    Minze Stuiver

    1978-01-01

    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

  6. Limiting future atmospheric carbon dioxide

    SciTech Connect

    Sarmiento, J.L.; Quere, C.L.; Pacala, S.W. [Princeton Univ., NJ (United States)] [Princeton Univ., NJ (United States)

    1995-03-01

    We estimate anthropogenic carbon emissions required to stabilize future atmospheric CO{sub 2} at various levels ranging from 350 ppm to 750 ppm. Over the next three centuries, uptake by the ocean and terrestrial biosphere would permit emissions to be 3 to 6 times greater than the total atmospheric increase, with each of them contributing approximately equal amounts. Owing to the nonlinear dependence of oceanic and terrestrial biospheric uptake on CO{sub 2} concentration, the uptake by these two sinks decreases substantially at higher atmospheric CO{sub 2} levels. The uptake also decreases with increased atmospheric CO{sub 2} growth rate. All the stabilization scenarios require a substantial future reduction in emissions. 57 refs., 20 figs., 3 tabs.

  7. Enriching blast furnace gas by removing carbon dioxide.

    PubMed

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

    2013-12-01

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

  8. Robust carbon dioxide reduction on molybdenum disulphide edges.

    PubMed

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

    2014-01-01

    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

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

    PubMed

    Nakano, Ryo; Ito, Shingo; Nozaki, Kyoko

    2014-04-01

    Although carbon dioxide has attracted broad interest as a renewable carbon feedstock, its use as a monomer in copolymerization with olefins has long been an elusive endeavour. A major obstacle for this process is that the propagation step involving carbon dioxide is endothermic; typically, attempted reactions between carbon dioxide and an olefin preferentially yield olefin homopolymerization. Here we report a strategy to circumvent the thermodynamic and kinetic barriers for copolymerizations of carbon dioxide and olefins by using a metastable lactone intermediate, 3-ethylidene-6-vinyltetrahydro-2H-pyran-2-one, which is formed by the palladium-catalysed condensation of carbon dioxide and 1,3-butadiene. Subsequent free-radical polymerization of the lactone intermediate afforded polymers of high molecular weight with a carbon dioxide content of 33 mol% (29 wt%). Furthermore, the protocol was applied successfully to a one-pot copolymerization of carbon dioxide and 1,3-butadiene, and one-pot terpolymerizations of carbon dioxide, butadiene and another 1,3-diene. This copolymerization technique provides access to a new class of polymeric materials made from carbon dioxide. PMID:24651200

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

    NASA Astrophysics Data System (ADS)

    Nakano, Ryo; Ito, Shingo; Nozaki, Kyoko

    2014-04-01

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

  11. Carbon Dioxide Production in the Oxidation of Organic

    E-print Network

    Steinbock, Oliver

    Carbon Dioxide Production in the Oxidation of Organic Acids by Cerium(IV) under Aerobic are oxidized to carbon dioxide. Hence, the determination of the stoichiometry between produced CO2 and reduced The study of oxidation of relatively low molecular weight carbonic acids by metal ions has been an active

  12. Development of a Carbon Dioxide Monitoring Rotorcraft Unmanned Aerial Vehicle

    E-print Network

    Zimmer, Uwe

    stage to prevent potential danger to workforce and material, and carbon capture and sequestration (CCSDevelopment of a Carbon Dioxide Monitoring Rotorcraft Unmanned Aerial Vehicle Florian Poppa and Uwe the development of a carbon dioxide (CO2) sensing rotorcraft unmanned aerial vehicle (RUAV) and the experiences

  13. www.sciam.com SCIENTIFIC AMERICAN 49 Pumping carbon dioxide

    E-print Network

    O'Donnell, Tom

    increasing attention: capturing carbon dioxide and storing, or seques- tering, it underground rather than re for capture and storage already exists and that the obstacles hindering implementa- tion seem to be surmountable. Carbon Dioxide Capture the combustion of fossil fuels pro- duces huge quantities of carbon

  14. Carbon Dioxide Capture by Chemical Absorption: A Solvent Comparison Study

    E-print Network

    1 Carbon Dioxide Capture by Chemical Absorption: A Solvent Comparison Study by Anusha Kothandaraman Students #12;2 #12;3 Carbon Dioxide Capture by Chemical Absorption: A Solvent Comparison Study by Anusha with electricity generation accounting for 40% of the total1 . Carbon capture and sequestration (CCS) is one

  15. Carbon dioxide: A substitute for phosgene

    SciTech Connect

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

    1997-03-01

    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.

  16. Carbon dioxide exchange and early old-field succession

    Microsoft Academic Search

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

    2006-01-01

    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

  17. Carbon Dioxide Sequestration and ECBM in the Powder River Basin

    Microsoft Academic Search

    L. B. Colmenares; M. D. Zoback

    2003-01-01

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

  18. Automated carbon dioxide cleaning system

    NASA Technical Reports Server (NTRS)

    Hoppe, David T.

    1991-01-01

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

  19. Carbon Dioxide Sequestration in Concrete Using Vacuum-Carbonation Alain Azar, Prof. Yixin Shao

    E-print Network

    Barthelat, Francois

    Carbon Dioxide Sequestration in Concrete Using Vacuum-Carbonation Alain Azar, Prof. Yixin Shao promising carbon uptake results and is a viable option for carbonation curing. Carbon sequestration increase in Carbon dioxide (CO2) emissions over the past five decades, specific ways to reduce

  20. Carbon Dioxide Transport through Membranes*

    PubMed Central

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

    2008-01-01

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

  1. Carbon dioxide absorbent and method of using the same

    SciTech Connect

    Perry, Robert James; O'Brien, Michael Joseph

    2014-06-10

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

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

    NASA Technical Reports Server (NTRS)

    Carlson, R. W.

    1999-01-01

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

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

    PubMed

    Carlson, R W

    1999-02-01

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

  4. Carbon dioxide utilization in the chemical industry

    SciTech Connect

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

    1996-12-31

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

  5. Carbon dioxide inhalation causes pulmonary inflammation.

    PubMed

    Abolhassani, Mohammad; Guais, Adeline; Chaumet-Riffaud, Philippe; Sasco, Annie J; Schwartz, Laurent

    2009-04-01

    The aim of this study was to assess whether one of the most common poisons of cellular respiration, i.e., carbon dioxide, is proinflammatory. CO(2) is naturally present in the atmosphere at the level of 0.038% and involved in numerous cellular biochemical reactions. We analyzed in vitro the inflammation response induced by exposure to CO(2) for 48 h (0-20% with a constant O(2) concentration of 21%). In vivo mice were submitted to increasing concentrations of CO(2) (0, 5, 10, and 15% with a constant O(2) concentration of 21%) for 1 h. The exposure to concentrations above 5% of CO(2) resulted in the increased transcription (RNase protection assay) and secretion (ELISA) of proinflammatory cytokines [macrophage inflammatory protein-1alpha (MIP-1alpha), MIP-1beta, MIP-2, IL-8, IL-6, monocyte chemoattractant protein-1, and regulated upon activation, normal T cell expressed, and, presumably, secreted (RANTES)] by epithelial cell lines HT-29 or A549 and primary pulmonary cells retrieved from the exposed mice. Lung inflammation was also demonstrated in vivo by mucin 5AC-enhanced production and airway hyperreactivity induction. This response was mostly mediated by the nuclear translocation of p65 NF-kappaB, itself a consequence of protein phosphatase 2A (PP2A) activation. Short inhibiting RNAs (siRNAs) targeted toward PP2Ac reversed the effect of carbon dioxide, i.e., disrupted the NF-kappaB activation and the proinflammatory cytokine secretion. In conclusion, this study strongly suggests that exposure to carbon dioxide may be more toxic than previously thought. This may be relevant for carcinogenic effects of combustion products. PMID:19136578

  6. Capture of carbon dioxide by hybrid sorption

    DOEpatents

    Srinivasachar, Srivats

    2014-09-23

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

  7. Searching for clues to ancient carbon dioxide

    SciTech Connect

    Appenzeller, T.

    1993-02-12

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

  8. 49 CFR 195.4 - Compatibility necessary for transportation of hazardous liquids or carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...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...

  9. 21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO 2) monitor.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 2014-04-01 false Cutaneous carbon dioxide (PcCO 2) monitor. 868...Monitoring Devices 868.2480 Cutaneous carbon dioxide (PcCO 2 ) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2 ) monitor...

  10. 46 CFR 167.45-45 - Carbon dioxide fire extinguishing system requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 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...

  11. 49 CFR 195.4 - Compatibility necessary for transportation of hazardous liquids or carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...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...

  12. 46 CFR 108.627 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 108.627...Equipment Markings and Instructions 108.627 Carbon dioxide and clean agent alarms. Each carbon dioxide alarm must be identified by...

  13. 46 CFR 97.37-9 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 2013-10-01 2013-10-01 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...

  14. 46 CFR 97.37-9 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 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...

  15. 46 CFR 147.65 - Carbon dioxide and halon fire extinguishing systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Carbon dioxide and halon fire extinguishing systems...for Particular Materials 147.65 Carbon dioxide and halon fire extinguishing systems. (a) Carbon dioxide or halon cylinders...

  16. 46 CFR 78.47-9 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 2013-10-01 2013-10-01 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...

  17. 21 CFR 862.1160 - Bicarbonate/carbon dioxide test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Bicarbonate/carbon dioxide test system. 862.1160 ...Systems 862.1160 Bicarbonate/carbon dioxide test system. (a) Identification. A bicarbonate/carbon dioxide test system is a device...

  18. 46 CFR 147.65 - Carbon dioxide and halon fire extinguishing systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Carbon dioxide and halon fire extinguishing systems...for Particular Materials 147.65 Carbon dioxide and halon fire extinguishing systems. (a) Carbon dioxide or halon cylinders...

  19. 46 CFR 78.47-9 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 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...

  20. 46 CFR 196.37-9 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...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...

  1. 21 CFR 868.1150 - Indwelling blood carbon dioxide partial pressure (PCO2) analyzer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Indwelling blood carbon dioxide partial pressure (PCO2) analyzer...Devices 868.1150 Indwelling blood carbon dioxide partial pressure (PCO2 ) analyzer...Identification. An indwelling blood carbon dioxide partial pressure PCO2...

  2. 21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO 2) monitor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 2013-04-01 false Cutaneous carbon dioxide (PcCO 2) monitor. 868...Monitoring Devices 868.2480 Cutaneous carbon dioxide (PcCO 2 ) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2 ) monitor...

  3. 46 CFR 167.45-45 - Carbon dioxide fire extinguishing system requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...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...

  4. 21 CFR 862.1160 - Bicarbonate/carbon dioxide test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Bicarbonate/carbon dioxide test system. 862.1160 ...Systems 862.1160 Bicarbonate/carbon dioxide test system. (a) Identification. A bicarbonate/carbon dioxide test system is a device...

  5. 21 CFR 868.1150 - Indwelling blood carbon dioxide partial pressure (PCO2) analyzer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...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...

  6. 76 FR 55846 - Hazardous Waste Management System: Identification and Listing of Hazardous Waste: Carbon Dioxide...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-09

    ...Listing of Hazardous Waste: Carbon Dioxide (CO2) Streams in Geologic Sequestration Activities AGENCY: Environmental...to conditionally exclude carbon dioxide (CO 2 ) streams...to conditionally exclude carbon dioxide (CO 2 )...

  7. 21 CFR 868.1150 - Indwelling blood carbon dioxide partial pressure (PCO2) analyzer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 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...

  8. 21 CFR 868.1150 - Indwelling blood carbon dioxide partial pressure (PCO2) analyzer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 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...

  9. 40 CFR 180.1049 - Carbon dioxide; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Carbon dioxide; exemption from the requirement...From Tolerances 180.1049 Carbon dioxide; exemption from the requirement of a tolerance. The insecticide carbon dioxide is exempted from the...

  10. 46 CFR 131.815 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 131.815 ...and Emergency Equipment 131.815 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire extinguishing...

  11. 40 CFR 180.1049 - Carbon dioxide; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Carbon dioxide; exemption from the requirement...From Tolerances 180.1049 Carbon dioxide; exemption from the requirement of a tolerance. The insecticide carbon dioxide is exempted from the...

  12. 46 CFR 131.815 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  13. 46 CFR 196.37-9 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 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...

  14. 46 CFR 108.627 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 108.627 ...Markings and Instructions 108.627 Carbon dioxide and clean agent alarms. Each carbon dioxide alarm must be identified by...

  15. 21 CFR 201.161 - Carbon dioxide and certain other gases.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  16. Effects of carbon dioxide on peak mode isotachophoresis: Simultaneous preconcentration and separation

    E-print Network

    Santiago, Juan G.

    Effects of carbon dioxide on peak mode isotachophoresis: Simultaneous preconcentration ions resulting from dissolved atmospheric carbon dioxid e to weakly disrupt isotachophoretic the hydration and carbamation reaction of dissolved atmospheric carbon dioxide, respectively. The width

  17. 46 CFR 78.47-9 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...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...

  18. 40 CFR 180.1049 - Carbon dioxide; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  19. 40 CFR 180.1049 - Carbon dioxide; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Carbon dioxide; exemption from the requirement...From Tolerances 180.1049 Carbon dioxide; exemption from the requirement of a tolerance. The insecticide carbon dioxide is exempted from the...

  20. 40 CFR 180.1049 - Carbon dioxide; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Carbon dioxide; exemption from the requirement...From Tolerances 180.1049 Carbon dioxide; exemption from the requirement of a tolerance. The insecticide carbon dioxide is exempted from the...

  1. Climatic and phenological controls on coherent regional interannual variability of carbon dioxide flux

    E-print Network

    Wisconsin at Madison, University of

    Climatic and phenological controls on coherent regional interannual variability of carbon dioxide carbon dioxide flux observations from five different ecosystems (deciduous forest, northern hardwood), Climatic and phenological controls on coherent regional interannual variability of carbon dioxide flux

  2. 21 CFR 868.1150 - Indwelling blood carbon dioxide partial pressure (PCO2) analyzer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 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...

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

    E-print Network

    Kaiser, Ralf I.

    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

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

    E-print Network

    commercial carbons and their gasification rates with carbon dioxide at a series of temperatures between 900 2' of the desired value. The carbon dioxide flow rate through the reactor was maintained constantMar., 1955 GASIFICATIONOF CARBONRODSWITH CARBONDIOXIDE 241 GASIFICATION OF CARBON RODS WITH CARBON

  5. Carbon dioxide research plan. A summary

    SciTech Connect

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

    1983-11-01

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

  6. Fixation of carbon dioxide by producing hydromagnesite from serpentinite

    Microsoft Academic Search

    Sebastian Teir; Sanni Eloneva; Carl-Johan Fogelholm; Ron Zevenhoven

    2009-01-01

    Fixing carbon dioxide (CO2) as carbonates using silicate-based materials is an interesting alternative option for storage of carbon dioxide. Suitable magnesium-rich rocks are distributed throughout the world. The magnesium silicate deposits in Eastern Finland alone could be sufficient for storing 10Mt CO2 each year during a period of 200300 years. Rocks potentially suitable for carbonation are already mined, processed, piled,

  7. 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.

  8. Six-fold coordinated carbon dioxide VI

    SciTech Connect

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

    2008-06-16

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

  9. Chemical Reactions in Supercritical Carbon Dioxide

    NASA Astrophysics Data System (ADS)

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

    1998-12-01

    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.

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

    NSDL National Science Digital Library

    Planet Nutshell

    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.

  11. Carbon dioxide sequestration in concrete in different curing environments

    E-print Network

    Wisconsin-Milwaukee, University of

    Carbon dioxide sequestration in concrete in different curing environments Y.-m. Chun, T.R. Naik, USA ABSTRACT: This paper summarizes the results of an investigation on carbon dioxide (CO2) sequestration in concrete. Concrete mixtures were not air entrained. Concrete mixtures were made containing

  12. A monitoring and diagnostic expert system for carbon dioxide capture

    Microsoft Academic Search

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

    2009-01-01

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

  13. Atmospheric carbon dioxide concentrations over the past 60 million years

    Microsoft Academic Search

    Paul N. Pearson; Martin R. Palmer

    2000-01-01

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

  14. Solid amine compounds as sorbents for carbon dioxide: A concept

    NASA Technical Reports Server (NTRS)

    Sutton, J. G.; Heimlich, P. F.; Tepper, E. H.

    1972-01-01

    Solid amine compounds were examined as possible absorbents for removal of carbon dioxide in life support systems of type which may be employed in high altitude aircraft, spacecraft, or submarines. Many solid amine compounds release absorbed carbon dioxide when heated in vacuum, therefore, when properly packaged spent amine compounds can be readily regenerated and put back into service.

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

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Still wines containing carbon dioxide. 26.222 ...From the Virgin Islands 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram...

  16. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Still wines containing carbon dioxide. 26.52 Section...Products From Puerto Rico 26.52 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram...

  17. A Tenuous Carbon Dioxide Atmosphere on Jupiter's Moon Callisto

    Microsoft Academic Search

    Robert W. Carlson

    1999-01-01

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

  18. Physiological Responses to Elevated Carbon Dioxide Levels in Buildings

    Microsoft Academic Search

    Saul Stricker; Marc Bourgeau; Eric Fonberg; Denis Parent

    1997-01-01

    Comparative tests were conducted involving 22 persons sleeping in a normal and in an elevated carbon dioxide (CO2) environment to determine respirato ry and urinary responses. Carbon dioxide levels in bedrooms with 2 occupants with the bedroom doors and windows closed can rise to 4,500 ppm during the night. The results indicate that the exposure levels encountered in these bedrooms

  19. Carbon dioxide escape and avoidance behavior in the brown rat

    Microsoft Academic Search

    Peter Van Sommers

    1963-01-01

    Rats were restrained in a small chamber through which various gas mixtures could be pumped. 3 rats were exposed to concentrations of carbon dioxide of 8%, 10%, and 15%. They successfully learned to escape regularly for 30-sec. periods by touching a metal tube. They were subsequently trained to avoid the onset of air containing similar carbon dioxide concentrations by pressing

  20. Open Nanoporous Morphologies from Polymeric Blends by Carbon Dioxide Foaming

    Microsoft Academic Search

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

    2002-01-01

    We report the formation of open nanoporous polymer films composed of homogeneous polysulfone\\/polyimide blends. Porosity is introduced by expansion of carbon dioxide-saturated films at elevated temperatures. To interpret details of the porous morphologies in terms of the experimental conditions during expansion, the glass transition temperature and carbon dioxide solubility of the dense film were examined at various blend compositions. We

  1. 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...

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

    E-print Network

    Rust, Bert W.

    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

  3. OXIDATION OF URANIUM ALLOYS IN CARBON DIOXIDE AND AIR

    Microsoft Academic Search

    J. E. Antill; K. A. Peakall

    1961-01-01

    Weight gain--time curves were obtained for alloys of uranium containing ; up to 7.3% silicon, 10% titanium, 5% vanadium, 10% zirconium, 15% molybdenum, 10% ; niobium, and 1% copper in carbon dioxide at 500--1000 deg C and in air at 500 deg ; C. Additions of titanium, molybdenum, niobium, and copper reduced the attack by ; carbon dioxide at 680--1000

  4. Pilot Plant Study of Carbon Dioxide Capture by Aqueous Monoethanolamine

    E-print Network

    Rochelle, Gary T.

    i Pilot Plant Study of Carbon Dioxide Capture by Aqueous Monoethanolamine Topical Report Prepared Pilot Plant Study of Carbon Dioxide Capture by Aqueous Monoethanolamine Ross Edward Dugas, M capture using monoethanolamine (MEA). MEA is an appropriate choice for a baseline study since

  5. Carbon Dioxide and Global Warming: A Failed Experiment

    ERIC Educational Resources Information Center

    Ribeiro, Carla

    2014-01-01

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

  6. Supercritical carbon dioxide explosion as a pretreatment for cellulose hydrolysis

    Microsoft Academic Search

    Yizhou Zheng; Ho-Mu Lin; Jingquan Wen; Ningjun Cao; Xuezhi Yu; George T. Tsao

    1995-01-01

    Cellulosic material Avicel was treated with supercritical carbon dioxide to increase the reactivity of cellulose, thereby to enhance the rate and the extent of cellulose hydrolysis. Upon an explosive release of the carbon dioxide pressure, the disruption of the cellulosic structure increases the accessible surface area of the cellulosic substrate to enzymatic hydrolysis. This explosion pretreatment enhances the rate of

  7. Cationic Polymerization of Vegetable Oils in Supercritical Carbon Dioxide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polymers derived from vegetable oils have been prepared in supercritical carbon dioxide (scCO2) medium by cationic polymerization. Boron trifluoride diethyl etherate BF3.O(C2H2)2 are used as initiator. Influences of polymerization temperature, initiator amount, and carbon dioxide pressure on the m...

  8. Solubility of carbon dioxide in propylene carbonate at elevated pressures and higher than ambient temperatures

    SciTech Connect

    Mantor, P.D.; Abib, O. Jr.; Song, K.Y.; Kobayashi, R.

    1982-07-01

    The solubility of carbon dioxide in propylene carbonate at elevated pressures and higher than ambient temperatures may assume increasing significance for the processing of carbon dioxide-rich gases issuing from natural reservoirs and/or carbon dioxide enhanced oil processing streams. Despite the fact that propylene carbonate has been used as solvent for its selective absorption of carbon dioxide from natural gases, the solubility data for carbon dioxide in propylene carbonate are highly restricted with respect to pressure, with respect to accuracy, and/or with respect to the number of isotherms studied. Data on the solubility of carbon dioxide in propylene carbonate are accordingly presented for several isotherms to cover reasonable processing pressures and temperatures.

  9. Carbon dioxide sequestration by ex-situ mineral carbonation

    SciTech Connect

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

    2000-01-01

    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.

  10. Kinetics of vibrational energy transfer in carbon dioxide and its mixtures with other gases

    Microsoft Academic Search

    S. A. Losev

    1976-01-01

    The paper reviews various types of vibrational energy transfer in carbon dioxide and mixtures which contain it, with emphasis on experimental results. Techniques for measuring vibrational energy transfer are discussed: ultrasonic, laser-fluorescence and gasdynamic methods. The following types of vibrational energy transfer are considered: (1) transfer between symmetric vibrations; (2) vibrational-translational transfer; (3) transfer between asymmetric and symmetric vibrations, and

  11. Combining power plant water needs and carbon dioxide storage using saline formations: Implications for carbon dioxide and water management policies

    Microsoft Academic Search

    Peter H. Kobos; Malynda A. Cappelle; Jim L. Krumhansl; Thomas A. Dewers; Andrea McNemar; David J. Borns

    2011-01-01

    Research involving management of carbon dioxide has increased markedly over the last decade as it relates to concerns over climate change. Capturing and storing carbon dioxide (CO2) in geological formations is one of many proposed methods to manage, and likely reduce, CO2 emissions from burning fossil fuels in the electricity sector. Saline formations represent a vast storage resource, and the

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

    Microsoft Academic Search

    1987-01-01

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

  13. Stable carbon isotope measurements using laser spectroscopy

    NASA Technical Reports Server (NTRS)

    Sauke, T. B.; Becker, J. F.

    1991-01-01

    The 2300 cm(exp -1) spectral region is especially interesting because (12)CO2 and (13)CO2 bands overlap in such a way that their rotational lines have approximately equal absorbance at the anticipated isotopic ratio (approximately 90) of carbon on Earth and Mars. Pairs of rotational lines we have studied are separated by as little as 0.050 cm(exp -1), but are well resolved with a tunable diode laser. Using sophisticated sweep integration and signal averaging techniques, we have measured the stable isotope ratio in carbon dioxide to a precision of better than 1 percent.

  14. Photobiological hydrogen production and carbon dioxide sequestration

    NASA Astrophysics Data System (ADS)

    Berberoglu, Halil

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

  15. From carbon dioxide to C{sub 2} organic molecules

    SciTech Connect

    Gong, J.K.; Wright, C.A.; Thorn, M. [Southeast Missouri State Univ., Cape Girardeau, MO (United States)] [and others

    1996-12-31

    Research on the conversion of carbon dioxide into C{sub 2} or higher organic molecules has received much attention in recent years. The key to the success of this research is carbon-carbon coupling. This paper reports the modified synthesis of a nickel carbon dioxide complex, (Cy{sub 3}P){sub 2}NiCO{sub 2}, (Cy = cyclohexane) and the {open_quotes}Wittig Reaction{close_quotes} of this coordinated nickel carbon dioxide complex. The formed nickel ketene complex, (Cy{sub 3}P){sub 2}Ni[{eta}{sup 2}- (C,O)-CH{sub 2}=C=O], has an unusual {eta}{sub 2}-C,O bonding mode instead of the normal {eta}{sup 2}-C,C for the later transition metals. The pathway of this {open_quotes}Witting Reaction{close_quotes} is an unprecedented example for a transition metal carbon dioxide complex.

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

    SciTech Connect

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

    2005-01-01

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

  17. Does carbon dioxide pool or stream in the subsurface?

    E-print Network

    Cardoso, Silvana S S

    2014-01-01

    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...

  18. Global carbon dioxide emissions from inland waters.

    PubMed

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

    2013-11-21

    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

  19. Biochemical Capture and Removal of Carbon Dioxide

    NASA Technical Reports Server (NTRS)

    Trachtenberg, Michael C.

    1998-01-01

    We devised an enzyme-based facilitated transport membrane bioreactor system to selectively remove carbon dioxide (CO2) from the space station environment. We developed and expressed site-directed enzyme mutants for CO2 capture. Enzyme kinetics showed the mutants to be almost identical to the wild type save at higher pH. Both native enzyme and mutant enzymes were immobilized to different supports including nylons, glasses, sepharose, methacrylate, titanium and nickel. Mutant enzyme could be attached and removed from metal ligand supports and the supports reused at least five times. Membrane systems were constructed to test CO2 selectivity. These included proteic membranes, thin liquid films and enzyme-immobilized teflon membranes. Selectivity ratios of more than 200:1 were obtained for CO2 versus oxygen with CO2 at 0.1%. The data indicate that a membrane based bioreactor can be constructed which could bring CO2 levels close to Earth.

  20. Estimated Carbon Dioxide Emissions in 2008: United States

    SciTech Connect

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

    2011-04-01

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

  1. Intraosseous Venography with Carbon Dioxide in Percutaneous Vertebroplasty: Carbon Dioxide Retention in Renal Veins

    SciTech Connect

    Komemushi, Atsushi, E-mail: kome64@yo.rim.or.jp; Tanigawa, Noboru; Kariya, Shuji; Kojima, Hiroyuki; Shomura, Yuzo; Tokuda, Takanori; Nomura, Motoo; Terada, Jiro; Kamata, Minoru; Sawada, Satoshi [Kansai Medical University, Department of Radiology (Japan)

    2008-11-15

    The objective of the present study was to determine the frequency of gas retention in the renal vein following carbon dioxide intraosseous venography in the prone position and, while citing references, to examine its onset mechanisms. All percutaneous vertebroplasties performed at our hospital from January to December 2005 were registered and retrospectively analyzed. Of 43 registered procedures treating 79 vertebrae, 28 procedures treating 54 vertebrae were analyzed. Vertebral intraosseous venography was performed using carbon dioxide as a contrast agent in all percutaneous vertebroplasty procedures. In preoperative and postoperative vertebral CT, gas retention in the renal vein and other areas was assessed. Preoperative CT did not show gas retention (0/28 procedures; 0%). Postoperative CT confirmed gas retention in the renal vein in 10 of the 28 procedures (35.7%). Gas retention was seen in the right renal vein in 8 procedures (28.6%), in the left renal vein in 5 procedures (17.9%), in the left and right renal veins in 3 procedures (10.7%), in vertebrae in 22 procedures (78.6%), in the soft tissue around vertebrae in 14 procedures (50.0%), in the spinal canal in 12 procedures (42.9%), and in the subcutaneous tissue in 5 procedures (17.9%). In conclusion, in our study, carbon dioxide gas injected into the vertebra frequently reached and remained in the renal vein.

  2. Redox Reactions of Metalloporphyrins and their Role in Catalyzed Reduction of Carbon Dioxide

    SciTech Connect

    Neta, P.

    2002-09-01

    Pulse radiolysis and laser photolysis are used to study redox processes of metalloporphyrins and related complexes in order to evaluate these light absorbing molecules as sensitizers and intermediates in solar energy conversion schemes. The main thrust of the current studies is to investigate the role of reduced metalloporphyrins as intermediates in the catalyzed reduction of carbon dioxide. Studies involve cobalt and iron porphyrins, phthalocyanines, corroles, and corrins as homogeneous catalysts for reduction of carbon dioxide in solution. The main aim is to understand the mechanisms of these photochemical schemes in order to facilitate their potential utilization.

  3. Coiled tubing drilling with supercritical carbon dioxide

    DOEpatents

    Kolle , Jack J. (Seattle, WA)

    2002-01-01

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

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

    SciTech Connect

    Lincoln, D.E.

    1990-05-01

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

  5. Viscosity behavior of carbon dioxide treated Cut Bank crude oil

    SciTech Connect

    Cady, G.V.; Mosawi, H.

    1995-12-31

    Carbon dioxide injection, either by huff and puff or displacement operations, results in a crude oil viscosity reduction at pressures below the miscibility conditions. Carbon dioxide miscibility occurs in reservoirs at miscible temperature and pressure, but these conditions are not possible in shallow reservoirs. Improved oil recovery in a shallow reservoir depends on the degree of viscosity reduction at the reservoir temperature and pressure. A recovery project`s success depends on the interaction between the carbon dioxide and the reservoir system. A research project carried out at Montana Tech to study the viscosity reduction and carbon dioxide solubility in Cut Bank crude oil at the reservoir`s prevailing temperature and near fracture pressure shows a viscosity reduction ratio (crude-carbon dioxide mixture to original dead oil viscosity) of 0.22 at a pressure of 1,000 psig and 90 F. An original mobility of 20 Md/cp improves to 91 Md/cp under a carbon dioxide recovery process at or near the reservoir`s fracture pressure. Based on the authors` research, improved oil recovery operations in the Cut Bank Field, Montana, is viable when using a commercial on site carbon dioxide recovery or generating system to minimize the cost of CO{sub 2} transportation. The major benefits are oil viscosity reduction, mobility ratio improvement, gas drive, and crude oil swelling.

  6. Alkali metal carbon dioxide electrochemical system for energy storage and/or conversion of carbon dioxide to oxygen

    NASA Astrophysics Data System (ADS)

    Hagedorn, Norman H.

    1991-09-01

    An alkali metal, such as lithium, is the anodic reactant, carbon dioxide or a mixture of carbon dioxide and carbon monoxide is the cathodic reactant, and carbonate of the alkali metal is the electrolyte in an electrochemical cell for the storage and delivery of electrical energy. Additionally, alkali metal-carbon dioxide battery systems include a plurality of such electrochemical cells. Gold is a preferred catalyst for reducing the carbon dioxide at the cathode. The fuel cell of the invention produces electrochemical energy through the use of an anodic reactant which is extremely energetic and light, and a cathodic reactant which can be extracted from its environment and therefore exacts no transportation penalty. The invention is therefore especially useful in extraterrestrial environments.

  7. Alkali metal carbon dioxide electrochemical system for energy storage and/or conversion of carbon dioxide to oxygen

    NASA Astrophysics Data System (ADS)

    Hagedorn, Norman H.

    1993-05-01

    An alkali metal, such as lithium, is the anodic reactant; carbon dioxide or a mixture of carbon dioxide and carbon monoxide is the cathodic reactant; and carbonate of the alkali metal is the electrolyte in an electrochemical cell for the storage and delivery of electrical energy. Additionally, alkali metal-carbon dioxide battery systems include a plurality of such electrochemical cells. Gold is a preferred catalyst for reducing the carbon dioxide at the cathode. The fuel cell of the invention produces electrochemical energy through the use of an anodic reactant which is extremely energetic and light, and a cathodic reactant which can be extracted from its environment and therefore exacts no transportation penalty. The invention is, therefore, especially useful in extraterrestrial environments.

  8. Moisture swing sorbent for carbon dioxide capture from ambient air.

    PubMed

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

    2011-08-01

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

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

    SciTech Connect

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

    2005-04-01

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

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

    SciTech Connect

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

    1994-12-31

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

  11. Carbon Dioxide in Exoplanetary Atmospheres: Rarely Dominant Compared to Carbon Monoxide and Water

    E-print Network

    Heng, Kevin

    2015-01-01

    We present a comprehensive study of the abundance of carbon dioxide in exoplanetary atmospheres. We construct analytical models of systems in chemical equilibrium that include carbon monoxide, carbon dioxide, water, methane and acetylene and relate the equilibrium constants of the chemical reactions to temperature and pressure via the tabulated Gibbs free energies. We prove that such chemical systems may be described by a quintic equation for the mixing ratio of methane. By examining the abundances of these molecules across a broad range of temperatures (spanning equilibrium temperatures from 600 to 2500 K), pressures (via temperature-pressure profiles that explore albedo and opacity variations) and carbon-to-oxygen ratios (from 0.1 to 100), we conclude that carbon dioxide is subdominant compared to carbon monoxide and water. Atmospheric mixing does not alter this conclusion if carbon dioxide is subdominant everywhere in the atmosphere. Carbon dioxide and carbon monoxide may attain comparable abundances if th...

  12. Cholesterol Aggregation and Interaction with Cholesterol Oxidase in Supercritical Carbon Dioxide

    Microsoft Academic Search

    T. W. Randolph; D. S. Clark; H. W. Blanch; J. M. Prausnitz

    1988-01-01

    High-pressure EPR spectroscopy indicates that cholesterol forms aggregates in supercritical carbon dioxide. In pure carbon dioxide, changes in cholesterol aggregate size or packing structure are observed with changing pressure. Near the critical point of carbon dioxide, cholesterol solubility is too low to permit significant aggregation, and monomeric cholesterol is observed. Addition of small amounts of dopants to supercritical carbon dioxide

  13. CARBON DIOXIDE -CO2 MSDS (DOCUMENT #001013) PAGE 1 OF 12 MATERIAL SAFETY DATA SHEET

    E-print Network

    Choi, Kyu Yong

    CARBON DIOXIDE - CO2 MSDS (DOCUMENT #001013) PAGE 1 OF 12 MATERIAL SAFETY DATA SHEET Prepared to U in an emergency? 1. PRODUCT IDENTIFICATION CHEMICAL NAME; CLASS: CARBON DIOXIDE - CO2, GASEOUS CARBON DIOXIDE - CO2, CRYOGENIC CARBON DIOXIDE - CO2, SOLID Document Number: 001013 PRODUCT USE: For general analytical

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

    SciTech Connect

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

    2010-11-09

    A novel method and system of separating carbon dioxide from flue gas is introduced. Instead of relying on large temperature or pressure changes to remove carbon dioxide from a solvent used to absorb it from flue gas, the ion pump method, as disclosed herein, dramatically increases the concentration of dissolved carbonate ion in solution. This increases the overlying vapor pressure of carbon dioxide gas, permitting carbon dioxide to be removed from the downstream side of the ion pump as a pure gas. The ion pumping may be obtained from reverse osmosis, electrodialysis, thermal desalination methods, or an ion pump system having an oscillating flow in synchronization with an induced electric field.

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

    DOEpatents

    Aines, Roger D.; Bourcier, William L.

    2014-08-19

    A novel method and system of separating carbon dioxide from flue gas is introduced. Instead of relying on large temperature or pressure changes to remove carbon dioxide from a solvent used to absorb it from flue gas, the ion pump method, as disclosed herein, dramatically increases the concentration of dissolved carbonate ion in solution. This increases the overlying vapor pressure of carbon dioxide gas, permitting carbon dioxide to be removed from the downstream side of the ion pump as a pure gas. The ion pumping may be obtained from reverse osmosis, electrodialysis, thermal desalination methods, or an ion pump system having an oscillating flow in synchronization with an induced electric field.

  16. Carbon dioxide warming of the early Earth.

    PubMed

    Arrhenius, G

    1997-02-01

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

  17. Carbon dioxide warming of the early Earth

    NASA Technical Reports Server (NTRS)

    Arrhenius, G.

    1997-01-01

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

  18. High temperature carbon dioxide separation membrane

    NASA Astrophysics Data System (ADS)

    Wade, Jennifer Lynn

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

  19. Scaling up carbon dioxide capture and storage: From megatons to gigatons Howard J. Herzog

    E-print Network

    Scaling up carbon dioxide capture and storage: From megatons to gigatons Howard J. Herzog MIT warming Carbon mitigation Low carbon energy technologies Carbon dioxide capture and storage (CCS) Carbon. Introduction Carbon dioxide (CO2) capture and storage (CCS) is a process consisting of the separation of CO2

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

    DOEpatents

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

    2013-01-29

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

  1. 9 CFR 313.5 - Chemical; carbon dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...On emerging from the carbon dioxide tunnel, the animals shall be in a state of...dioxide gas shall be administered in a tunnel which is designed to permit the effective exposure of the animal. Two types of tunnels, based on the same principle, are in...

  2. 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)

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

    2013-12-01

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

  3. Pretreatment for cellulose hydrolysis by carbon dioxide explosion

    SciTech Connect

    Zheng, Y.; Lin, H.M.; Tsao, G.T. [Purdue Univ., West Lafayette, IN (United States). Lab of Renewable Resources Engineering] [Purdue Univ., West Lafayette, IN (United States). Lab of Renewable Resources Engineering

    1998-11-01

    Cellulosic materials were treated with supercritical carbon dioxide to increase the reactivity of cellulose, thereby to enhance the rate and the extent of cellulose hydrolysis. In this pretreatment process, the cellulosic materials such as Avicel, recycled paper mix, sugarcane bagasse and the repulping waste of recycled paper are placed in a reactor under pressurized carbon dioxide at 35 C for a controlled time period. Upon an explosive release of the carbon dioxide pressure, the disruption of the cellulosic structure increases the accessible surface area of the cellulosic substrate to enzymatic hydrolysis. Results indicate that supercritical carbon dioxide is effective for pretreatment of cellulose. An increase in pressure facilitates the faster penetration of carbon dioxide molecules into the crystalline structures, thus more glucose is produced from cellulosic materials after the explosion as compared to those without the pretreatment. This explosion pretreatment enhances the rate of cellulosic material hydrolysis as well as increases glucose yield by as much as 50%. Results from the simultaneous saccharification and fermentation tests also show the increase in the available carbon source from the cellulosic materials for fermentation to produce ethanol. As an alternative method, this supercritical carbon dioxide explosion has a possibility to reduce expense compared with ammonia explosion, and since it is operated at the low temperature, it will not cause degradation of sugars such as those treated with steam explosion due to the high-temperature involved.

  4. INTERIOR VIEW OF COLUMN TOPS. CARBON DIOXIDE BUBBLED THROUGH AMMONIONATED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW OF COLUMN TOPS. CARBON DIOXIDE BUBBLED THROUGH AMMONIONATED SALT BRINE TO MAKE BICARBONATE OF SODA. - Solvay Process Company, SA Wetside Building, Between Willis & Milton Avenue, Solvay, Onondaga County, NY

  5. Infrared energy levels and intensities of carbon dioxide

    Microsoft Academic Search

    L. S. Rothman; W. S. Benedict

    1978-01-01

    Updated tables of vibrational energy levels, molecular constants, band origins, and intensities for carbon dioxide in the infrared region of the spectrum are presented. These tables are references for the AFGL Atmospheric Absorption Line Parameters Compilation.

  6. Infrared energy levels and intensities of carbon dioxide.

    PubMed

    Rothman, L S; Benedict, W S

    1978-08-15

    Updated tables of vibrational energy levels, molecular constants, band origins, and intensities for carbon dioxide in the infrared region of the spectrum are presented. These tables are references for the AFGL Atmospheric Absorption Line Parameters Compilation. PMID:20203829

  7. Mechanisms for mechanical trapping of geologically sequestered carbon dioxide

    E-print Network

    Cohen, Yossi

    Carbon dioxide (CO[subscript 2]) sequestration in subsurface reservoirs is important for limiting atmospheric CO[subscript 2] concentrations. However, a complete physical picture able to predict the structure developing ...

  8. Electrochemically-mediated amine regeneration for carbon dioxide separations

    E-print Network

    Stern, Michael C. (Michael Craig)

    2014-01-01

    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 ...

  9. Atmospheric concentrations of carbon dioxide, methane and nitrous oxide

    NSDL National Science Digital Library

    IPCC (Intergovernmental Panel of Climate Change)

    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).

  10. Synthesis of Amides and Lactams in Supercritical Carbon Dioxide

    E-print Network

    Mak, Xiao Yin

    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 ...

  11. Porosity Development in Activated Carbons Prepared from Walnut Shells by Carbon Dioxide or Steam Activation

    Microsoft Academic Search

    Juan F. Gonza?lez; Silvia Roma?n; Carmen M. Gonzalez-Garc ; J. M. Valente Nabais; Angel L. Ortiz

    2009-01-01

    The influence of carbon dioxide and steam as activating agents on the porosity development of activated carbons produced from walnut shells was investigated. The study was made covering a wide range of burnoff (12-76%) and employing different temperatures and times: in carbon dioxide activation, 850 C varying the activation time in the range 60-480 min, and in steam activation, 700,

  12. Field results from 3 campaigns to validate the performance of the Miniaturized Laser Heterodyne Radiometer (mini-LHR) for measuring carbon dioxide and methane in the atmospheric column

    NASA Astrophysics Data System (ADS)

    Wilson, E. L.; Clarke, G. B.; Melroy, H.; Miller, J. H.; Allan, G. R.; McLinden, M. L.; Ott, L.; Holben, B. N.

    2013-12-01

    We present mini-LHR measurements of column CO2 and CH4 from our recent field campaign at Mauna Loa Observatory (MLO), HI in May 2013 as well as column CO2 measurements from Castle Airport in Merced, CA during the ASCENDS DC-8 campaign in February 2013, and column CO2 measurements made at the NOAA LEF/TCCON (Total Column Carbon Observing Network) site in Park Falls, WI in September 2012. The mini-LHR was completely automated at the MLO location and operates in tandem with an AERONET sun photometer and measures CO2 and CH4 every 15 minutes during daylight hours in clear sky conditions. Laser heterodyne radiometry has been an established receiver technique since the 1970s and has been used to measure a range of atmospheric gases such as ozone, water vapor, methane, ammonia, chlorine monoxide, and nitrous oxide. The mini-LHR is a passive variation on this technique that uses sunlight as the light source to measure absorption of CO2 and CH4 in the infrared. In this instrument, sunlight is collected with collimation optics mounted to the AERONET sun tracker and superimposed with laser light in a single mode fiber coupler. The signals are mixed in a fast photoreceiver (InGaAs detector), and the RF (radio frequency) beat signal is extracted. Changes in concentration of the trace gas are realized through analyzing changes in the beat frequency amplitude. Miniaturization was made possible through the use of smaller distributive feedback (DFB) lasers and related fiber optic components that have recently become commercially available and inexpensive through progress in the telecommunications industry. In addition to the complementary aerosol optical depth measurement, tandem operation with AERONET provides a clear pathway for the mini-LHR to be expanded into a global monitoring network. AERONET has more than 450 instruments worldwide and offers coverage in key arctic regions (not covered by OCO-2) where accelerated warming due to the release of CO2 and CH4 from thawing tundra and permafrost is a concern. A mini-LHR global ground network can also provide an uninterrupted data record that will both bridge gaps in data sets and offer validation for key flight missions such as OCO-2, OCO-3, and ASCENDS. Currently, the only ground global network that routinely measures multiple greenhouse gases in the atmospheric column is TCCON with 18 operational sites worldwide and two in the US. Cost and size of TCCON installations will limit the potential for expansion. We offer a low-cost (<$30K/unit) solution to supplement these measurements.

  13. Membranes for separation of carbon dioxide

    DOEpatents

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

    2011-03-01

    Methods for separating carbon dioxide from a fluid stream at a temperature higher than about 200.degree. C. with selectivity higher than Knudsen diffusion selectivity include contacting a porous membrane with the fluid stream to preferentially transport carbon dioxide. The porous membrane includes a porous support and a continuous porous separation layer disposed on a surface of the porous support and extending between the fluid stream and the porous support layer. The porous support comprises alumina, silica, zirconia, stabilized zirconia, stainless steel, titanium, nickel-based alloys, aluminum-based alloys, zirconium-based alloys or a combination thereof. Median pore size of the porous separation layer is less than about 10 nm, and the porous separation layer comprises titania, MgO, CaO, SrO, BaO, La.sub.2O.sub.3, CeO.sub.2, HfO.sub.2, Y.sub.2O.sub.3, VO.sub.z, NbO.sub.z, TaO.sub.z, ATiO.sub.3, AZrO.sub.3, AAl.sub.2O.sub.4, A.sup.1FeO.sub.3, A.sup.1MnO.sub.3, A.sup.1CoO.sub.3, A.sup.1NiO.sub.3, A.sup.2HfO.sub.3, A.sup.3 CeO.sub.3, Li.sub.2ZrO.sub.3, Li.sub.2SiO.sub.3, Li.sub.2TiO.sub.3, Li.sub.2HfO.sub.3, A.sup.4N.sup.1.sub.yO.sub.z, Y.sub.xN.sup.1.sub.yO.sub.z, La.sub.xN.sup.1.sub.yO.sub.z, HfN.sup.2.sub.yO.sub.z, or a combination thereof; wherein A is La, Mg, Ca, Sr or Ba; A.sup.1 is La, Ca, Sr or Ba; A.sup.2 is Ca, Sr or Ba; A.sup.3 is Sr or Ba; A.sup.4 is Mg, Ca, Sr, Ba, Ti or Zr; N.sup.1 is V, Nb, Ta, Cr, Mo, W, Mn, Si or Ge; N.sup.2 is V, Mo, W or Si; x is 1 or 2; y ranges from 1 to 3; and z ranges from 2 to 7.

  14. Diffusion of ethanolcarbon dioxide in silica gel

    Microsoft Academic Search

    P. Wawrzyniak; G. Rogacki; J. Pruba; Z. Bartczak

    1998-01-01

    Extraction of a primary solvent with liquid or supercritical carbon dioxide is the most difficult to control stage in low-temperature silica aerogel production. Diffusion of primary ethanol through alcogel structure to surrounding CO2 was investigated in carefully controlled experiments with cylindrical alcogel samples. Changes of the alcohol concentration in carbon dioxide leaving the autoclave were followed with on-line chromatograph analysis

  15. Seawater pH and Anthropogenic Carbon Dioxide

    E-print Network

    Gerald E. Marsh

    2013-07-18

    In 2005, the Royal Society published a report titled "Ocean acidification due to increasing atmospheric carbon dioxide". The report's principal conclusion-that average ocean pH could decrease by 0.5 units by 2100-is demonstrated here to be consistent with a linear extrapolation of very limited data. It is also shown that current understanding of ocean mixing, and of the relationship between pH and atmospheric carbon dioxide concentration, cannot justify such an extrapolation.

  16. Detection of aerosolized cells during carbon dioxide laparoscopy

    Microsoft Academic Search

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

    1998-01-01

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

  17. Sagebrush and grasshopper responses to atmospheric carbon dioxide concentration

    Microsoft Academic Search

    R. H. Johnson; D. E. Lincoln

    1990-01-01

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

  18. Carbon dioxide solubility in 1-ethyl-3-methylimidazolium trifluoromethanesulfonate

    Microsoft Academic Search

    Allan N. Soriano; Bonifacio T. Doma Jr.; Meng-Hui Li

    2009-01-01

    In this work, we present new solubility results for carbon dioxide in the ionic liquid 1-ethyl-3-methylimidazolium trifluoromethanesulfonate for temperatures ranging from (303.2 to 343.2)K and pressures up to 5.9MPa using a thermogravimetric microbalance. Carbon dioxide solubilities were determined from absorption saturation (equilibrium) results at each fixed temperature and pressure. The buoyancy effect was accounted for in the evaluation of the

  19. Extraction of lemongrass essential oil with dense carbon dioxide

    Microsoft Academic Search

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

    2001-01-01

    Lemongrass (Cymbopogon citratus) essential oil was extracted with dense carbon dioxide at 2350C and 85120 bar. The composition of samples collected during the first and the last hours of the extraction experiments was analyzed by gas chromatographymass spectrometry, and coextraction of cuticular waxes was observed. Liquid carbon dioxide extracts had a larger quantity of coextracted waxes than the supercritical extracts.

  20. Stomatal response to carbon dioxide: aperature and chloroplast structure

    E-print Network

    Spence, Richard Douglas

    1982-01-01

    STOMATAL RESPONSE TO CARBON DIOXIDE: APERTURE AND CHLOROPLAST STRUCTURE A Thesis by RICHARD DOUGLAS SPENCE, JR. Submitted to the Graduate College of Texas ARM Univeristy in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE December 1982 Major Subject: Bioengineering STOMATAL RESPONSE TO CARBON DIOXIDE: APERTURE Ah!D CHLOROPLAST STRUCTURE A Thesis by RICHARD DOUGLAS SPENCE, JR. Approved as to style and content by: P. J. . Shar pe (Chairman of Committee...

  1. Renewable and metal-free carbon nanofibre catalysts for carbon dioxide reduction

    NASA Astrophysics Data System (ADS)

    Kumar, Bijandra; Asadi, Mohammad; Pisasale, Davide; Sinha-Ray, Suman; Rosen, Brian A.; Haasch, Richard; Abiade, Jeremiah; Yarin, Alexander L.; Salehi-Khojin, Amin

    2013-12-01

    The development of an efficient catalyst system for the electrochemical reduction of carbon dioxide into energy-rich products is a major research topic. Here we report the catalytic ability of polyacrylonitrile-based heteroatomic carbon nanofibres for carbon dioxide reduction into carbon monoxide, via a metal-free, renewable and cost-effective route. The carbon nanofibre catalyst exhibits negligible overpotential (0.17?V) for carbon dioxide reduction and more than an order of magnitude higher current density compared with the silver catalyst under similar experimental conditions. The carbon dioxide reduction ability of carbon nanofibres is attributed to the reduced carbons rather than to electronegative nitrogen atoms. The superior performance is credited to the nanofibrillar structure and high binding energy of key intermediates to the carbon nanofibre surfaces. The finding may lead to a new generation of metal-free and non-precious catalysts with much greater efficiency than the existing noble metal catalysts.

  2. Cycling Carbon: Seeing How Plants Use Carbon Dioxide in the Lab

    NSDL National Science Digital Library

    This activity discusses the nature of carbon, the different types of compounds in which it exists (e.g. charcoal, glucose, carbon dioxide), the biochemical reactions in which it takes part (photosynthesis and respiration), the range of processes that carbon and carbon compounds are involved in on Earth, and how these link together to form the carbon cycle. This activity demonstrates the uptake of carbon dioxide by plants, using Elodea as the example. Students are reminded that Elodea is a pond plant that lives below the water surface and thus extracts dissolved carbon dioxide from the water rather than directly from the atmosphere as terrestrial plants do. The students will discover that the carbon exchange between living things and the atmosphere mostly happens through photosynthesis and respiration. During the growing season leaves take up carbon dioxide and carbon is then stored in the living biomass.

  3. Beneficial Use of Carbon Dioxide in Precast Concrete Production

    SciTech Connect

    Shao, Yixin

    2014-03-31

    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.

  4. Carbon Dioxide Reforming of Methane to Syngas by Thermal Plasma

    NASA Astrophysics Data System (ADS)

    Sun, Yanpeng; Nie, Yong; Wu, Angshan; Ji, Dengxiang; Yu, Fengwen; Ji, Jianbing

    2012-03-01

    Experiments were conducted on syngas preparation from dry reforming of methane by carbon dioxide with a DC arc plasma at atmospheric pressure. In all experiments, nitrogen gas was used as the working gas for thermal plasma to generate a high-temperature jet into a horizontal tube reactor. A mixture of methane and carbon dioxide was fed vertically into the jet. In order to obtain a higher conversion rate of methane and carbon dioxide, chemical energy efficiency and fuel production efficiency, parametric screening studies were conducted, in which the volume ratio of carbon dioxide to methane in fed gases and the total flux of fed gases were taken into account. Results showed that carbon dioxide reforming of methane to syngas by thermal plasma exhibited a larger processing capacity, higher conversion of methane and carbon dioxide and higher chemical energy efficiency and fuel production efficiency. In addition, thermodynamic simulation for the reforming process was conducted. Experimental data agreed well with the thermodynamic results, indicating that high thermal efficiency can be achieved with the thermal plasma reforming process.

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

    Microsoft Academic Search

    Schmitt

    1980-01-01

    Papers presented at the Carbon Dioxide and Climate Research Program Conference are included in this volume. Topics discussed are: the carbon cycle; modeling the carbon system; climatic response due to increased CO; climate modeling; the use of paleoclimatic data in understanding climate change; attitudes and implications of CO; social responses to the CO problem; a scenario for atmospheric CO to

  6. The solid carbon dioxide penetrator: A technological option?

    SciTech Connect

    Murray, C.N.; Bidoglio, G.; Ribeiro, J. [Commission of the European Communities, Varese (Italy). Joint Research Centre; Visintini, L. [Aermacchi S.p.A., Varese (Italy)

    1994-12-31

    A solution for permanently sequestering anthropogenic carbon dioxide may be proposed on the basis of the observation of the occurrence of carbonate-rich sediments, which are ubiquitous in sedimentary formations of the ocean at depths above the carbonate compensation depth at around 4 km, and which form a natural net sink of carbon. Thus to circumvent the uncertainty related to presently studied ocean disposal options based on pumping of liquid carbon dioxide or hydrate slurry injection at depth, with the risk of short-term physical and biological oceanographic processes returning an important fraction of it to the atmosphere, techniques for disposal should concentrate on using the natural geochemical storage properties of deep marine geological formations. It is proposed that the concept of disposal of anthropogenic carbon dioxide in marine geological formations could be investigated making u of solid carbon dioxide free fall penetrators. The technique proposed would depend on the fact that carbon dioxide can be obtained as a solid by cooling to {minus}78.5 C. The overall density is approximately one and a half times {approximately} 1.56 kg.dm{sup {minus}3} that of seawater. If the solid was shaped as a torpedo and then left to fall through the water column it would penetrate quite deeply into the soft sediments. This conclusion is based on in-situ investigations using penetrators that were studied as a disposal option for other solid wastes. 40 refs., 3 figs.

  7. Using carbon dioxide as a building block in organic synthesis.

    PubMed

    Liu, Qiang; Wu, Lipeng; Jackstell, Ralf; Beller, Matthias

    2015-01-01

    Carbon dioxide exits in the atmosphere and is produced by the combustion of fossil fuels, the fermentation of sugars and the respiration of all living organisms. An active goal in organic synthesis is to take this carbon--trapped in a waste product--and re-use it to build useful chemicals. Recent advances in organometallic chemistry and catalysis provide effective means for the chemical transformation of CO? and its incorporation into synthetic organic molecules under mild conditions. Such a use of carbon dioxide as a renewable one-carbon (C1) building block in organic synthesis could contribute to a more sustainable use of resources. PMID:25600683

  8. Euthanasia of neonatal mice with carbon dioxide

    USGS Publications Warehouse

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

    2005-01-01

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

  9. Miscibility of Polymers in Supercritical Carbon Dioxide

    NASA Astrophysics Data System (ADS)

    Defelice, Jeffrey; Lipson, Jane

    2014-03-01

    We have developed a simple model that allows us to correlate underlying thermodynamic behavior with trends in miscibility, which we have applied to mixtures of polymers and supercritical carbon dioxide (scCO2) . scCO2 is considered a ``green'' solvent, making it an attractive choice over familiar organic solvents. Experimental cloud point investigations have determined the miscibility of a diverse array of polymers in scCO2. Properties of these polymers such as fluorination, alkyl group size, and molecular weight have a strong effect on mixture miscibility. Although polymer/scCO2 mixtures have been modeled with some success in the past, the ability of an equation of state (EOS) to make accurate predictions has yet to be demonstrated. We have used a simple EOS to study several of these mixtures. We draw insight from the trends observed via our parameterization of pure component experimental data and discuss how the use of pure component information, alone, leads us to predictions about mixture behavior. This will ultimately aid in our understanding of what is controlling polymer miscibility in scCO2.

  10. Low-temperature data for carbon dioxide

    E-print Network

    Azreg-Anou, Mustapha

    2014-01-01

    We investigate the empirical data for the vapor pressure (154$ \\leq$$T$$\\leq$196 K) and heat capacity (15.52$ \\leq$$T$$\\leq$189.78 K) of the solid carbon dioxide. The approach is both theoretical and numerical, using a computer algebra system (CAS). From the latter point of view, we have adopted a cubic piecewise polynomial representation for the heat capacity and reached an excellent agreement between the available empirical data and the evaluated one. Furthermore, we have obtained values for the vapor pressure and heat of sublimation at temperatures below 195 right down to 0 K. The key prerequisites are the: 1) Determination of the heat of sublimation of 26250 J$\\cdot$mol\\textsuperscript{-1} at vanishing temperature and 2) Elaboration of a `linearized' vapor pressure equation that includes all the relevant properties of the gaseous and solid phases. It is shown that: 1) The empirical vapor pressure equation derived by Giauque & Egan remains valid below the assumed lower limit of 154 K (similar argument ...

  11. Electrocatalytic Reduction of Carbon Dioxide to Methane

    NASA Technical Reports Server (NTRS)

    Sammells, Anthony F.; Spiegel, Ella F.

    2008-01-01

    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.

  12. Effects of carbon dioxide on laryngeal receptors

    SciTech Connect

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

    1990-02-26

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

  13. Miniaturized Amperometric Solid Electrolyte Carbon Dioxide Sensors

    NASA Technical Reports Server (NTRS)

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

    2006-01-01

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

  14. Carbon Dioxide Exchange in Complex Topography

    NASA Astrophysics Data System (ADS)

    Reif, Matthias; Rotach, Mathias; Wohlfahrt, Georg; Gohm, Alexander

    2015-04-01

    On a global scale the budget of carbon dioxide (CO_2) bears a quite substantial uncertainty, which is commonly understood to be mainly due to land-surface exchange processes. In this project we investigate to what extent complex topography can amplify these land-surface exchange processes. The hypothesis is that, on the meso-scale, topography adds additional atmospheric mechanisms that drive the exchange of CO2 at the surface. This sensitivity model study investigates an idealized sine shaped valley with the atmospheric numerical model Weather Research and Forecasting (WRF) coupled to the community land model (CLM) to study the effect of complex topography on the CO2 budget compared to flat terrain. The experiment is designed to estimate the effect of the topography during maximum ecosystem exchange in summer using meteorological and ecosystem conditions at solstice, the 21. of June. Systematic variation of meteorological initial conditions, plant functional types and the topography creates an ensemble that unveils the fundamental factors that dominate the differences of CO2 between simulations with topography compared to plain surfaces in the model. The sign and magnitude of the difference between the CO2 exchange over topography and over a plain simulation are strongly dependent on the CLM plant functional type, the initial temperature, the initial relative humidity, the latitude and the area height distribution of the topography. However, in this model experiment the topography is, in the mean, a sink to the CO2 budget in the order of 5% per day.

  15. Carbon dioxide sequestration by direct aqueous mineral carbonation

    SciTech Connect

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

    2000-01-01

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

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

    Microsoft Academic Search

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

    1999-01-01

    A 400 record of atmospheric carbon dioxide levels has been estimated by applying a CO 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

  17. Scaling up carbon dioxide capture and storage: From megatons to gigatons Howard J. Herzog

    E-print Network

    Scaling up carbon dioxide capture and storage: From megatons to gigatons Howard J. Herzog MIT Global warming Carbon mitigation Low carbon energy technologies Carbon dioxide capture and storage (CCS) Carbon dioxide (CO2) capture and storage (CCS) is the only technology that can reduce CO2 emissions

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

    SciTech Connect

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

    2004-07-01

    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.

  19. A selective and efficient electrocatalyst for carbon dioxide reduction.

    PubMed

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

    2014-01-01

    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. PMID:24476921

  20. A selective and efficient electrocatalyst for carbon dioxide reduction

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

    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.