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1

Carbon Dioxide Laser Guidelines  

PubMed Central

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

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

2009-01-01

2

Fractional Carbon Dioxide Laser Resurfacing  

PubMed Central

Currently available ablative fractional CO2 lasers provide excellent results and diminish down time with fewer complications than previous generation CO2 lasers. Mechanisms of action, treatment parameters, as well as pre- and postoperative care will be discussed. PMID:23904820

Ramsdell, William M.

2012-01-01

3

Pulsed-discharge carbon dioxide lasers  

NASA Technical Reports Server (NTRS)

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

Willetts, David V.

1990-01-01

4

Endoscopic Carbon Dioxide Laser Photocoagulation Of Bleeding Canine Gastric Ulcers  

NASA Astrophysics Data System (ADS)

This is the first report which describes carbon dioxide laser photocoagulation of upper gastrointestinal bleeding via a flexible endoscope, using an infrared transmitting siver nalide fiber. Various laser parameters were checked to determine the optimal conditions for hemostasis. Both the acute effects of laser irradiation on tissue and the chronic effects on healing process were examined. Preliminary results indicate that carbon dioxide laser beam can successfully photocoagulate moderately bleeding ulcers.

Gal, Dov; Ron, Nimrod; Orgad, Uri; Katzir, Abraham

1987-04-01

5

21 CFR 179.43 - Carbon dioxide laser for etching food.  

...2014-04-01 2014-04-01 false Carbon dioxide laser for etching food. 179.43 Section 179...Radiation Sources 179.43 Carbon dioxide laser for etching food. Carbon dioxide laser light may be safely used for etching...

2014-04-01

6

Superpulsed carbon dioxide laser: an update on cutaneous surgical applications  

NASA Astrophysics Data System (ADS)

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.

Wheeland, Ronald G.

1990-06-01

7

Carbon dioxide laser microsurgery of the uterine tube.  

PubMed

The carbon dioxide (CO2) laser was used to perform microsurgical excision of obstructed tubal segments in rabbit and human subjects. Approximation of the freshly severed tubes by means of laser "welding" was evaluated in both groups investigated. More important, the laser beam cuts accurately and atraumatically while sealing small vascular channels. Scanning electron microscopic studies of the human fallopian tube following laser surgery were done to determine the extent of tissue injury. At a distance of 1 mm distal to the vaporization and necrotic impact zone, normal tubal anatomy was observed. Follow-up data are presented for 7 women who underwent laser beam tuboplasty between 1979 and 1980. The principle advantages of the CO2 laser are its precise control, minimal tissue injury, and hemostatic properties. PMID:6787488

Baggish, M S; Chong, A P

1981-07-01

8

Measurement of Carbon Dioxide Column via Space Borne Laser Absorption  

NASA Technical Reports Server (NTRS)

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

Heaps, WIlliam S.

2007-01-01

9

Treatment of lymphangioma circumscriptum using fractional carbon dioxide laser ablation.  

PubMed

Lymphangioma circumscriptum remains a challenging entity to treat given anatomic considerations and a significant tendency for recurrence regardless of the modality selected. Surgical excision offers the greatest potential for definitive management but is often beset by procedural morbidity and suboptimal cosmetic outcomes. A range of palliative options have been reported for the treatment of lymphangioma circumscriptum, with varying degrees of associated efficacy and morbidity. This report describes the novel use of fractional carbon dioxide laser ablation for the treatment of lymphangioma circumscriptum, with promising cosmetic results and durable symptomatic relief. PMID:23758048

Shumaker, Peter R; Dela Rosa, Kristina M; Krakowski, Andrew

2013-01-01

10

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

E-print Network

Carbon dioxide UV laser-induced fluorescence in high-pressure flames W.G. Bessler a , C. Schulz a dioxide is investigated with excitation between 215 and 255 nm with spectrally resolved detection in 5 dioxide (CO2) and water (H2O), based on mea- surements in engines [11] and high-pressure flames [12

Lee, Tonghun

11

Research on Human Skin Injury Thresholds for Pulsed Carbon Dioxide Lasers.  

National Technical Information Service (NTIS)

These experiments made use of pulsed carbon dioxide lasers to irradiate the flexor side skin of people's forearms. Observations were made of the occurrence rate of cutaneous erythema and the appearance times for erythema. Cutaneous erythema occurrence rat...

C. Ji S. Liangshun, Q. Huanwen, L. Enjiang, Z. Jianjun

1996-01-01

12

Clinical study on 71 anorectal cases treated by carbon dioxide laser  

NASA Astrophysics Data System (ADS)

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

Li, Gui-hua

1993-03-01

13

The NASA high power carbon dioxide laser: A versatile tool for laser applications  

NASA Technical Reports Server (NTRS)

A closed-cycle, continuous wave, carbon dioxide high power laser has been designed and fabricated to support research for the identification and evaluation of possible high power laser applications. The device is designed to generate up to 70 kW of laser power in annular shape beams from 1 to 9 cm in diameter. Electric discharge, either self sustained or electron beam sustained, is used for excitation. This laser facility provides a versatile tool on which research can be performed to advance the state-of-the-art technology of high power CO2 lasers in such areas as electric excitation, laser chemistry, and quality of output beams. The facility provides a well defined, continuous wave beam for various application experiments, such as propulsion, power conversion, and materials processing.

Lancashire, R. B.; Alger, D. L.; Manista, E. J.; Slaby, J. G.; Dunning, J. W.; Stubbs, R. M.

1976-01-01

14

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

NASA Technical Reports Server (NTRS)

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

Guinn, K.

1994-01-01

15

Ultrastructure of Collagen Thermally Denatured by Microsecond Domain Pulsed Carbon Dioxide Laser  

Microsoft Academic Search

Background: Clinical improvement in photodam- aged skin after carbon dioxide (CO2) laser resurfacing is thought to result in part from thermal collagen shrinkage. The presence of such collagen has not been unequivocally demonstrated. To identify and charac- terize the morphological features of collagen after CO2 laser exposure, we irradiated ex vivo human facial skin and bovine calcaneus tendon with microsecond

Kristin M. Kirsch; Brian D. Zelickson; Christopher B. Zachary; Whitney D. Tope

16

Ultrastructure of Collagen Thermally Denatured by Microsecond Domain Pulsed Carbon Dioxide Laser  

Microsoft Academic Search

Background: Clinical improvement in photodam- aged skin after carbon dioxide (CO2) laser resurfacing is thought to result in part from thermal collagen shrinkage. The presence of such collagen has not been unequivocally demonstrated. To identify and charac- terize the morphological features of collagen after CO2 laser exposure, we irradiated ex vivo human facial skin and bovine calcaneus tendon with microsecond

Kristin M. Kirsch; Brian D. Zelickson; Christopher B. Zachary; Whitney D. Tope

1998-01-01

17

The NASA high-power carbon dioxide laser - A versatile tool for laser applications  

NASA Technical Reports Server (NTRS)

The NASA Lewis Research Center has designed and fabricated a closed-cycle, continuous wave (CW), carbon dioxide (CO2) high-power laser to support research for the identification and evaluation of possible high-power laser applications. The device is designed to generate up to 70 kW of laser power in annular-shape beams from 1 to 9 cm in diameter. Electric discharge, either self-sustained or electron-beam-sustained, is used for excitation. This laser facility can be used in two ways. First, it provides a versatile tool on which research can be performed to advance the state-of-the-art technology of high-power CO2 lasers in such areas as electric excitation, laser chemistry, and quality of output beams, all of which are important whether the laser application is government or industry oriented. Second, the facility provides a well-defined, continuous wave beam for various application experiments, such as propulsion, power conversion, and materials processing.

Lancashire, R. B.; Alger, D. L.; Manista, E. J.; Slaby, J. G.; Dunning, J. W.; Stubbs, R. M.

1977-01-01

18

Identifying isomers of carbon-dioxide clusters by laser-driven Coulomb explosion  

NASA Astrophysics Data System (ADS)

Clusters usually exhibit unique structures as an intermediate form of matter. However, their structures are still difficult to be determined with available experimental techniques. There are many structure distinct isomers for carbon-dioxide clusters. Here we report an experimental and theoretical joint study to determine the structures of the lowest-energy isomers. In the experiment, we exploded carbon-dioxide clusters by laser-driven multiple ionization and obtained precise momentum vectors of explosion fragments for each explosion channel. In the theory, we calculated low-energy structures of carbon-dioxide clusters and simulated their explosion dynamics. In comparison with the momentum vectors of explosion fragments, the lowest-energy isomers were identified for carbon-dioxide dimers, trimers, and tetramers.

Xie, Xiguo; Wu, Cong; Liu, Yirong; Huang, Wei; Deng, Yongkai; Liu, Yunquan; Gong, Qihuang; Wu, Chengyin

2014-09-01

19

Rhinophyma: Carbon dioxide laser with computerized scanner is still an outstanding treatment.  

PubMed

The cosmetic deformity produced by rhinophyma is characterized by nodular hypertrophy of the nasal skin. A retrospective review and analysis of nine consecutive patients with moderate and major rhinophyma treated with scanned carbon dioxide laser was performed. A particular method of continuous scanner use is described. This report demonstrates excellent cosmetic results and no major postoperative complications or recurrence of the condition after 1 year of follow up for seven patients. Two more patients had been followed up for 1 month at the time this paper was written. Scanned carbon dioxide laser is safe and highly effective treatment for rhinophyma. PMID:19916975

Lim, Shueh-Wei; Lim, Shueh-Wen; Bekhor, Phillip

2009-11-01

20

Carbon dioxide  

NSDL National Science Digital Library

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

Arie Melamed-Katz (None;)

2007-06-19

21

Design and calculation of ground-to-air transmitting optical system of carbon-dioxide laser communicator  

Microsoft Academic Search

Transmitting optical sys tem was part of maneuverable type Carbon-Dioxide atmospheric Laser Communicator, which consists of Carbon-Dioxide laser, acousto-optical modulator, focusing lens, collimating lens and transmitting antenna. Ground-to-air communication distance up to 15km, error bit rate not more than 10-9. Image and speech can be transmitted separately with half duplex. Method for design major optical devices of ground-to-air laser communication

Hongtao Zhang; FuChang Yin; Qiugui Wang

2002-01-01

22

[Monitoring the flux of carbon dioxide gas with tunable diode laser absorption spectroscopy].  

PubMed

The greenhouse effect exacerbated by the increase of Carbon-containing gases is the more important causes of the climate change, It is very meaningful to the large-scale flux of carbon dioxide detection for the estimate the contributions of the main greenhouse gases in the atmosphere of various errestrial eco-systems. Tunable diode laser absorption spectroscopy (TDLAS) is a highly sensitive, highly selective and fast time response trace gas detection technique. In the present paper, the authors used a DFB laser was used as the light source, and by employing wavelength modulation method, and measuring the second harmonic signal of one absorption line near 1.573 microm of carbon dioxide molecule, the authors built a system for online monitoring of carbon dioxide concentration within the optical path of more than 700 meters at different heights. Combined with Alonzo Mourning -Obukhov length and characteristic velocity detected by large aperture scintillometer, the flux of carbon dioxide gas within one day calculated by the formula is within--1.5-2.5, breaking through the phenomenon of only providing the flux of trace gases near the ground at present, makking the measurement of trace gas fluxes within a large area possible. PMID:21428084

Song, Xue-Mei; Liu, Jian-Guo; Zhang, Yu-Jun; Zeng, Zong-Yong; He, Ying; Cui, Yi-Ben; Chen, Yin; Tian, Yong-Zhi; Zhang, Liang

2011-01-01

23

The potential alveolar hazard of carbon dioxide laser-induced smoke.  

PubMed

Carbon dioxide laser is a continuous wave laser, it is well known for its capacity of tremendous smoke production while contact with tissue. Smoke may cause nausea, vomiting, headache and airway irritation. Smoke particles 0.5-2 micrometers in diameter usually travel down the tracheobronchial tree and lodge in the alveoli posing a health hazard. The objectives of this study were to evaluate possible health hazards of carbon dioxide laser smoke in the operating room environment, by determining the size and density of smoke particles also determine the efficacy of surgical masks as a smoke protectant. Ten fresh specimens of papillomatous tissue obtained from the patients were lased by carbon dioxide laser in a continuous mode. The plume generated was collected by 0.45 micrometers pore size microfilter which was attached to the tip of a suction hose connecting the smoke evacuator. The effectiveness of 2 types of commonly used surgical masks were also determined by trapping the smoke after passing through each mask using the same model. Smoke particles were evaluated by scanning electron microscope. The smoke particle density of microfilter that directly trap plume averaged 6 particles/mm2, particles ranging in size from 0.5-27 micrometers, of which 70 per cent were 0.8 micrometers. For the particles trapped after passing through both cotton and paper surgical mask, the size were ranging from 1.6-37 micrometers where 65 per cent were 3.7 micrometers and the particle density average 2.7/mm2. We concluded that the smoke particles derived from carbon dioxide laser application are within the alveolar hazard zone. The conventional surgical masks may not be an effective tool against laser smoke hazard. PMID:9623022

Kunachak, S; Sobhon, P

1998-04-01

24

Use of a carbon dioxide laser to treat ceruminous gland hyperplasia in a cat.  

PubMed

This case report describes the skin condition ceruminous gland hyperplasia of the ears of a cat. The diagnosis was made through histopathology. Treatment consisted of carbon dioxide laser ablation of the cystic structures and postoperative care associated with the surgery, as well as a hydrolyzed protein diet, weekly ear cleaning and intermittent topical corticosteroid drops in the ears to minimize the reoccurrence of the cysts. PMID:22328586

Corriveau, Lorraine Ann

2012-06-01

25

Design of catalytic monoliths for closed-cycle carbon dioxide lasers  

NASA Technical Reports Server (NTRS)

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

Herz, Richard K.

1988-01-01

26

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

NASA Astrophysics Data System (ADS)

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

Chan, Kenneth H.; Fried, Daniel

2011-03-01

27

Carbon dioxide laser energy disperses human papillomavirus deoxyribonucleic acid onto treatment fields.  

PubMed

The possibility of dispersing viral deoxyribonucleic acid during carbon dioxide laser treatment of human papillomavirus-containing genital infections has been investigated with a commercially available dot blot hybridization technique. The viral ribonucleic acid probes were specific for groups of human papillomavirus types 6/11, 16/18, and 31/33/35. Laser energy was delivered by continuous-wave mode and the plume of smoke was evacuated by a vacuum suction system. Samples were taken with Dacron swabs from lesional tissues of 43 patients as well as from the treated areas and from the 5 cm surrounding normal skin before and after laser vaporization. Human papillomavirus deoxyribonucleic acid was identified in swabs from 34 of 43 (79%) lesional tissues and 7 of 43 (16%) treatment fields. Although a trend for higher human papillomavirus deoxyribonucleic acid positivity in laser margins after therapy (7/43, 16%) than before (4/43, 9%) was observed, the rates were not statistically significant. It is concluded that carbon dioxide laser energy disperses human papillomavirus deoxyribonucleic acid onto treatment fields and the adjacent normal epithelium. Viral contamination of treated areas may be reduced by positioning the fume evacuator within 1 cm of the field of laser vaporization and cleaning the treated areas and surrounding tissue after therapy. PMID:2171340

Ferenczy, A; Bergeron, C; Richart, R M

1990-10-01

28

Dissociation phenomena in electron-beam sustained carbon dioxide lasers  

NASA Technical Reports Server (NTRS)

A number of applications are emerging requiring efficient, long pulse, long-life sealed CO2 lasers. Examples include the proposed NASA and ESA wind lidars. Electron-beam sustained discharge devices are strong contenders. Unlike self-sustained discharges, e-beam sustenance readily provides efficient performance from large volume discharges and offers pulse lengths well in excess of the microsecond or so generally associated with self-sustained devices. In the case of the e-beam sustained laser, since the plasma is externally maintained and operated at electric field strengths less than that associated with the glow to arc transition, the discharges can be run even in the presence of strongly attacking species such as O2. Build up of large levels of attacking contaminants is nevertheless undesirable as their presence reduces the current drawn by the plasma and thus the pumping rate to the upper laser level. The impedance rise leads to a mismatch of the pulse forming network with a consequent loss of control over energy deposition, operating E/N, and gain. Clearly CO2 dissociation rates, the influence of dissociation products on the discharge and gain, and tolerance of the discharge to these products need to be determined. This information can then be used to assess co-oxidation catalyst requirements for sealed operation.

Harris, Michael R.; Willetts, David V.

1990-01-01

29

Selective removal of demineralization using near infrared cross polarization reflectance and a carbon dioxide laser  

NASA Astrophysics Data System (ADS)

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

Chan, Kenneth H.; Fried, Daniel

2012-01-01

30

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

PubMed Central

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

Chan, Kenneth H.; Fried, Daniel

2012-01-01

31

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

PubMed

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

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

2011-01-01

32

Design of catalytic monoliths for closed-cycle carbon dioxide lasers  

NASA Technical Reports Server (NTRS)

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

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

1989-01-01

33

Mitigation of surface damage growth by hydrofluoric acid etching combined with carbon dioxide laser treatment  

NASA Astrophysics Data System (ADS)

Damage sites as large as 600 ?m in fused silica surface were successfully mitigated with a new protocol by hydrofluoric acid (HF) etching combined with carbon dioxide laser treatment. The damage sites were first etched in 40% HF solution to blunt the fractures, and then the etched damage sites were smoothed with a CO2 laser. It has been found that the etching rate of damaged material in the lateral direction is larger than in the longitudinal direction; thus, an optimized etching time was chosen to etch the damage sites based on the etching ratio. Three types of damage test methods were used to confirm the mitigation efficiency of the protocol. The results indicate that the damage resistance capability of mitigated sites can recover to the level of pristine substrate.

Jiang, Yong; Yuan, Xiaodong; He, Shaobo; Zheng, Wanguo; Wang, Haijun; L, Haibing; Ren, Wei; Luo, Chengsi; Liu, Chunming; Xiang, Xia; Zu, Xiaotao

2012-08-01

34

Selective Removal of Residual Orthodontic Composite Using a Rapidly Scanned Carbon Dioxide Laser with Spectral Feedback  

NASA Astrophysics Data System (ADS)

Background and Objective: Excessive heat accumulation within the tooth, incomplete removal of composite, and variable damage to the enamel are shortcomings of using conventional burs to remove residual orthodontic composite after debonding fixed appliances. The objective of this study was to determine if composite could be selectively removed from the enamel surface using a rapidly scanned carbon dioxide laser controlled by spectral feedback. Materials and Methods: A carbon dioxide laser operating at a wavelength of 9.3 microm with a pulse duration of 10-15 micros and a pulse repetition rate of 200 Hz was used to selectively remove composite from the buccal surfaces of 21 extracted teeth. GrenGloo(TM) composite was used to better visualize residual composite and the amount of enamel lost was measured with optical microscopy. A spectral feedback system utilizing a miniature spectrometer was used to control the laser scanning system. Pulpal temperature measurements were performed during composite removal to determine if there was excessive heat accumulation. Results: The amount of enamel lost averaged 22.7microm +/- 8.9 and 25.3 microm +/- 9.4 for removal at 3.8 and 4.2 J/cm2, respectively. An average maximum temperature rise of 1.9C +/- 1.5 was recorded, with no teeth approaching the critical value of 5.5C. The average time of composite removal was 19.3 +/- 4.1 seconds. Conclusions: Residual orthodontic composite can be rapidly removed from the tooth surface using a rapidly scanned CO2 laser with spectral feedback, with minimal temperature rise within the pulp and with minimal damage to the underlying enamel surface.

Hirasuna, Krista

35

Photodynamic Therapy with Ablative Carbon Dioxide Fractional Laser in Treatment of Actinic Keratosis  

PubMed Central

Background Recently, photodynamic therapy (PDT) has been shown to be an effective first-line treatment for actinic keratosis (AK). However, a major limitation of PDT is the long incubation time required to allow penetration of the photosensitizer. Objective The aim of this study was to assess if pretreatment with an ablative carbon dioxide (CO2) fractional laser can reduce the incubation time of the photosensitizer. Methods Initially, 29 patients with a total of 34 AK lesions were treated with an ablative CO2 fractional laser at Ajou University Hospital between January and December 2010. Immediately after the laser treatment, topical 20% 5-aminolevulinic acid or methyl-aminolevulinate was applied to the AK lesions and incubated for 70 to 90 minutes. Then, the treated areas were illuminated with a red light source. Improvement was clinically or histologically assessed eight weeks after the treatment. Results In spite of the short incubation time, 24 lesions (70.6%) showed a complete response (CR) within three sessions of PDT (10 lesions a clinical CR and 14 lesions a clinical/histological CR). There were no significant side effects associated with the combination of ablative CO2 fractional laser and PDT. Conclusion Ablative CO2 fractional laser may be considered an additional treatment option for reducing the incubation time of the photosensitizer in PDT. PMID:24371387

Jang, Yong Hyun; Lee, Dong Jun; Shin, Jaeyoung; Kang, Hee Young; Lee, Eun-So

2013-01-01

36

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

SciTech Connect

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

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

1990-06-01

37

Visual sensing and range measurement by scanning of carbon dioxide laser  

NASA Astrophysics Data System (ADS)

A laser vision sensor has been developed to enable range measurement and identification of targets through flames, smoke, and fog which are invisible to the human eye. This vision sensor employs a 10.6 micrometers -wavelength carbon dioxide laser for its long wavelength. The target is scanned two-dimensionally by the laser beam, directed by a pair of galvanometer mirrors, to produce the target image and measure the range of the target. The laser beam, amplitude-modulated to 5 MHz with an electro-optic modulator, is projected onto a target, and the reflected beam is detected by a cadmium mercury telluride detector. The phase difference between the projected and reflected light signals is used to provide range data up to 30 m. The indoor test is carried out with a 1 cubic meter box in which flames, smoke, and fog can be generated. The laser beam is projected through this box, and the targets behind this box are detected. The reproduced image is sufficient for identification through flames, smoke, and fog.

Kawata, Koichi; Takahashi, Hidemi; Yamada, Osamu; Kimura, Minoru; Naito, Hiroshi

1992-11-01

38

Carbon dioxide power cycle  

Microsoft Academic Search

An improved direct fired power system generating and employing a combustion gas which includes carbon dioxide or a working fluid including a combustion chamber for burning a mixture which includes oxygen, carbonaceous fuel and recycled carbon dioxide working fluid at a first pressure of above 1100 PSI thereby providing a combustion gas which includes carbon dioxide and water at substantially

Osgerby

1985-01-01

39

Combined carbon dioxide laser and bipolar electrocoagulation: another option to treat rhinophyma.  

PubMed

Rhinophyma is a progressive and disfiguring disorder of the nose characterized by hyperplasia of the sebaceous glands and dermal tissue, representing the end-stage of rosacea. Four male patients affected by a moderate-severe rhinophyma were treated using a combined therapy with carbon dioxide laser and bipolar electrocoagulation. All patients achieved marked cosmetic results with minimal scarring. Various surgical approaches have been described to treat this condition but as yet there is no agreement in the literature on the ideal treatment. This combined method provides a bloodless operative field which allows the sculpting of the hypertrophic areas, leading to a good cosmetic outcome and a pain-free postoperative recovery. PMID:19365784

Cravo, Mariana; Miguel Canelas, Maria; Carlos Cardoso, Jos; Vieira, Ricardo; Figueiredo, Amrico

2009-01-01

40

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

NASA Astrophysics Data System (ADS)

Simultaneous concentration measurements of the three main stable carbon dioxide isotopologues ( 16O 12C 16O, 16O 13C 16O and 18O 12C 16O) in ambient air are demonstrated. The instrument employs a quasi-room temperature, pulsed quantum cascade laser emitting at 4.3 ?m. Both the laser and the IR detector are thermoelectrically cooled, which greatly facilitates cryogenic-free, continuous operation. The Allan plot of the time series of the retrieved spectroscopic ratio [ 13CO 2]/[ 12CO 2] shows a variance minimum that corresponds to 0.16 for ?13C with an averaging time of about 500 s. To demonstrate the feasibility of high precision in situ isotope ratio measurements, the instrument was operated in the field and provided continuous mixing ratio values for all three CO 2 isotopologues at 1 s time resolution. The spectroscopically derived isotopic ratios were compared to the standard laboratory-based isotope-ratio mass spectrometer measurements made on field-collected flask samples. At stable laser operation, the two data sets agreed within 0.28.

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

2008-01-01

41

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

Microsoft Academic Search

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

Seth David Humphries

2008-01-01

42

The carbon dioxide cycle  

USGS Publications Warehouse

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

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

2005-01-01

43

Nature-Like Photosynthesis of Water and Carbon Dioxide with Femtosecond Laser Induced Self-Assembled Metal Nanostructures  

Microsoft Academic Search

Large-scale replication of the natural process of photosynthesis is a crucial subject of storing solar energy and saving our environment. Here, we report femtosecond laser induced self-assembled metal nanostructure arrays, which are easily mass producible on earth-abundant metals, can directly synthesize liquid and solid hydrocarbon compounds from carbon dioxide, water, and sunlight at a production rate of more than 1

Cong Wang; Mengyan Shen; Haibin Huo; Haizhou Ren; Fadong Yan; Michael Johnson

2009-01-01

44

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

PubMed

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 treated with carbon dioxide laser and the other half with electrocoagulation. The vapor produced by each form of therapy was collected with a dry filter vacuum apparatus and analyzed for the presence of papillomavirus. Vapor from human plantar warts was analyzed for the presence of human papillomavirus DNA, because there is no infectivity assay for human papillomavirus. Of plantar warts treated, five of eight laser-derived vapors and four of seven electrocoagulation-derived vapors were positive for human papillomavirus DNA. Greater amounts of papillomavirus DNA were usually recovered in the laser vapor than in the electrocoagulation vapor from the same wart. Bioassay readily detected infectious bovine papillomavirus in the vapor from bovine warts treated with either modality; more virus was present in laser-derived material. A surgical mask was found capable of removing virtually all laser- or electrocoagulation-derived virus, strongly suggesting that such masks can protect operators from potential inhalation exposure to papillomavirus. PMID:2545749

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

1989-07-01

45

Surgical treatment of rhinophyma using carbon dioxide (CO2) laser and pulsed dye laser (PDL).  

PubMed

Rhinophyma is a slowly progressive, benign dermatological disorder of the nose. The most widely accepted theory is that rhinophyma is the end stage of chronic rosacea. The primary reason for its excision is cosmetic deformity. Many treatment modalities have been described, including CO(2) laser. This method provides a very dry surgical field, which allows the sculpting of the hypertrophic areas. Pulsed dye laser (PDL) is a safe and effective treatment, resulting in a significant improvement in erythema, telangiectases, symptoms and quality of life. We report the case of a 63-year-old Caucasian man with a 2-year history of rapid progression rhinophyma. The patient was submitted to five CO(2) laser sessions, followed by three PDL sessions. Favourable re-epithelization of the surfaces treated with CO(2) laser was achieved within a very short period of time. PDL post-treatment purpura lasted a medium of 12 days. After 12 months of follow-up the patient remains without evidence of relapse. To our knowledge, this is the first case described of treatment using a combination of the CO(2) laser and PDL. PMID:20331343

Moreira, Ana; Leite, Ins; Guedes, Rita; Baptista, Armando; Mota, Gioconda

2010-04-01

46

Carbon Dioxide Removal  

NSDL National Science Digital Library

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

History, American M.

2008-01-01

47

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

NASA Technical Reports Server (NTRS)

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.

Herz, Richard K.

1989-01-01

48

Synergistic effects of sequential carbon dioxide and neodymium:yttrium aluminum garnet laser injuries. Experimental observations and measurements  

SciTech Connect

The carbon dioxide and neodymium:yttrium aluminum garnet lasers have well documented but characteristically different biological effects, yet little is known about their cumulative, synergistic, or paradoxical effects when used sequentially on living tissue. Using a Merrimack ML 880 laser, a series of superimposed CO/sub 2/ and Nd:YAG lesions in various combinations were produced on the undersurface of dog tongues. Therapeutic time and power settings were chosen and the number of applications varied, with suitable controls. Observations and measurements were made on acute, healing, and healed lesions. All lesions were excised and submitted for routine hematoxylin and eosin histology. Acute lesions were also assessed for cell viability using rhodamine 123 as a supravital marker. The results show that, even though all the lesions eventually heal, the actual cell damage produced by the Nd:YAG laser is much more than is suggested by the size of the acute lesion. This cell damage can be reduced by the surface carbonization produced by initial application of the CO/sub 2/ laser. Higher surface temperatures are reached in this combination with less fibrosis and scarring than equal energy counterparts where the Nd:YAG laser was applied first. The knowledge of these synergistic effects can be used to advantage in the clinical setting. The rhodamine 123 technique also appears to be a valid measure of acute thermal tissue injury.

Primrose, W.J.; McDonald, G.A.; O'Brien, M.J.; Vaughan, C.W.; Strong, M.S.

1987-01-01

49

Atmospheric Carbon Dioxide  

NSDL National Science Digital Library

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

Rohde, Robert A.; (from published NOAA data)

50

Bench Remarks: Carbon Dioxide.  

ERIC Educational Resources Information Center

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

Bent, Henry A.

1987-01-01

51

8, 73157337, 2008 Carbon dioxide  

E-print Network

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

Paris-Sud XI, Université de

52

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

53

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

PubMed Central

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

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

2014-01-01

54

Modeling Carbon Dioxide Levels  

NSDL National Science Digital Library

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

2009-01-01

55

CARBON DIOXIDE FIXATION.  

SciTech Connect

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

FUJITA,E.

2000-01-12

56

Optical-fiber-to-waveguide coupling using carbon-dioxide-laser-induced long-period fiber gratings.  

PubMed

Optical fibers are expected to play a role in chip-level and board-level optical interconnects because of limitations on the bandwidth and level of integration of electrical interconnects. Therefore, methods are needed to couple optical fibers directly to waveguides on chips and on boards. We demonstrate optical-fiber-to-waveguide coupling using carbon-dioxide laser-induced long-period fiber gratings (LPFGs). Such gratings can be written in standard fiber and offer wavelength multiplexing-demultiplexing performance. The coupler fabrication process and the characterization apparatus are presented. The operation and the wavelength response of a LPFG-based optical-fiber-to-waveguide directional coupler are demonstrated. PMID:16127916

Bachim, Brent L; Ogunsola, Oluwafemi O; Gaylord, Thomas K

2005-08-15

57

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

SciTech Connect

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

Viswanathan, V.K.

1981-01-01

58

Carbon dioxide affects global ecology  

Microsoft Academic Search

Man's activities are changing the carbon dioxide and oxygen content of the entire atmosphere. These changes may, in turn, affect worldwide weather and the growth of plants. Under normal conditions, the amounts of carbon dioxide and oxygen in the atmosphere remain approximately in equilibrium on a year-to-year basis. The atmosphere today contains about 21% oxygen and about 0.032% carbon dioxide

Eugene K. Peterson

1969-01-01

59

Carbon Dioxide Capture and Disposal  

NASA Astrophysics Data System (ADS)

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

Lackner, K. S.

2002-05-01

60

Carbon dioxide sequestration by mineral carbonation  

Microsoft Academic Search

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

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

2007-01-01

61

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

NASA Astrophysics Data System (ADS)

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.

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

1990-06-01

62

Carbon dioxide and climate  

NASA Astrophysics Data System (ADS)

The earth's climate is getting warmer because of a buildup of carbon dioxide in the atmosphere that will continue well into the next century, according to a report released October 20 by the National Research Council (NRC), the research arm of the National Academy of Sciences. As the result of a 2-year study commissioned by Congress, the NRC's Carbon Dioxide Assessment Committee predicts a global temperature rise of as much as 4.5C by the year 2100, enough to shift weather patterns, raise sea levels, and eliminate agriculture in some parts of the world. What's more, the trend seems inevitable even drastic changes in our energy use would not prevent the warmup, according to the committee's findings.CO2, the major contributor to a thermal greenhouse effect that traps re-radiated heat in the atmosphere, has risen from a concentration of 315 parts per million (ppm) to 340 ppm in one generation, largely as a result of the use of fossil fuels. Sometime in the third quarter of the next century, the report predicts, the concentration will probably be double the current level. The result will be a global warming of surface air of between 1.5 and 4.5C, with temperature rises relatively greater at the poles.

63

Carbon Dioxide Reduction Through Urban Forestry  

E-print Network

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

Standiford, Richard B.

64

Carbon Dioxide Capture and Disposal  

Microsoft Academic Search

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

K. S. Lackner

2002-01-01

65

Coral reefs and carbon dioxide  

SciTech Connect

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

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

1996-03-01

66

Carbon Dioxide Landscape  

NASA Technical Reports Server (NTRS)

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.

2004-01-01

67

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

SciTech Connect

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)

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

2010-06-23

68

CARBON DIOXIDE AND OUR OCEAN LEGACY  

E-print Network

of carbon dioxide from the atmosphere, or nearly half of the fossil fuel carbon emissions over this periodCARBON DIOXIDE AND OUR OCEAN LEGACY G Carbon Dioxide: Our Role The United States is the single. Every day the average American adds about 118 pounds of carbon dioxide to the atmos- phere, due largely

69

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

NASA Astrophysics Data System (ADS)

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

Young, William P.

2000-05-01

70

Carbon dioxide laser turbinectomy versus submucosal diathermy of hypertrophied turbinates. Histopathological prospective study  

NASA Astrophysics Data System (ADS)

Aim: To assess suspected turbinate mucosal distractive changes of CO2 laser partial turbinectomy as compared to submucosal diathermy technique of hypertrophied inferior turbinates and thus risk of appearance of mucosal atrophic changes. Introduction: CO2 laser turbinotomy or turbinectomy has become an established well documented line of treatment of hypertrophied inferior turbinates not responding to medical treatment. Although there have been several reports discussing the clinical aspects of laser turbinectomy, but exact pathological changes that take place following laser application to the turbinate have not been described completely and clearly. For this reason this study was conducted to confirm these possible histopathological changes and compared with those following submucosal diathermy technique. Patients and methods: Twenty patients with chronic hypertrophied inferior turbinates and presenting mainly with nasal obstruction, ten out of them were subjected to CO2 laser turbinectomy while other half underwent to submucosal diathermy technique. Tiny biopsies were taken immediately after surgery (within one week after surgery ), as well as 4-6 weeks later and processed for further histopathological evaluation. Results: By 100%, the all patients of two groups showed areas of epithelial loss were observed immediately after both techniques. 4-6 weeks after laser application 60% of patients showed normal epithelial areas as compared to second group where 20% of patients who showed normal epithelial picture. Conclusion: CO2 laser turbinectomy can be considered as more preservative technique for nasal mucosa as well as the function of the nose as compared to submucosal diathermy technique.

Mohamed Bofares, Khalid

2010-05-01

71

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

PubMed Central

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

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

1998-01-01

72

Carbon Dioxide Emissions and Carbonation Sensors  

Microsoft Academic Search

The gases with higher heat capacities than those of O2 and N2 cause greenhouse effects. Carbon dioxide (CO2) is the main greenhouse gas associated with global climate change. At the present time, coal is responsible for 3040% of world CO2 emissions from fossil fuels. There was a higher correlation between the amount of carbon dioxide emission and percentage of carbon

A. Demirbas

2007-01-01

73

A new endotracheal tube for carbon dioxide and KTP laser surgery of the aerodigestive tract.  

PubMed

We have tested the fire-resistance of a new endotracheal tube designed for use in laser surgery of the upper aerodigestive tract. This Teflon/metallic-wrapped silicone tube seems capable of withstanding occasional, accidental pulsed laser impact at power settings used clinically (1 to 10 watts) without fire. On rare occasions when continuous mode is used, the tube seems capable of withstanding at least several seconds of continuous irradiation at clinical power settings without igniting. When used with other recommended safety procedures, this tube should minimize the risk of endotracheal tube fire from accidental laser impact. PMID:8437882

Ossoff, R H; Aly, A; Gonzales, D; Koriwchak, M J; Houchin, N

1993-01-01

74

Energy Balance and Temperature in a Carbon Dioxide Laser Produced Plasma.  

NASA Astrophysics Data System (ADS)

The absorption of intense (LESSTHEQ)10('14) W/cm('2) CO(,2) laser radiation by an underdense plasma is investigated experimentally. The plasma is produced by the CO(,2) laser beam focussed onto a stabilized laminar gas jet emanating from a Laval nozzle. The electron temperature of the laser produced plasma is measured by soft x-ray diagnostics which yield a 300 eV thermal and a 2000 eV suprathermal temperature. Time resolved studies are made of the radial expansion of the plasma to determine the absorbed energy and temperature using a modified blast wave analysis that involves the identification of the Chapman-Jouguet detonation point in the expansion. The absorbed energy is also determined from Ulbricht sphere photometry. Information on the plasma dimensions and electron density is obtained by time resolved ruby laser interferometry. The electron temperature and absorbed energy measurements are used to corroborate one another and to provide a self -consistent picture of the laser plasma coupling. Although vacuum laser intensities are sufficiently high where saturation of collisional (inverse bremsstrahlung), absorption is expected to occur, the experimental evidence indicates that linear inverse bremsstrahlung accounts for the observed thermal electron temperature and measured level of absorption. The energy balance shows that there is a sufficient level of absorption to accommodate the measured thermal electron temperature as well as <15% of the electrons at a 2 keV suprathermal temperature.

Popil, Roman Ewhen

75

Carbon Dioxide and Ocean Acidification  

NSDL National Science Digital Library

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

Lewis, Chris

76

a Study on CW Carbon Dioxide Laser Etching of Silicate Glasses  

NASA Astrophysics Data System (ADS)

Laser etching of silicate glasses has been studied. Samples of fused silica, borosilicate glasses, and soda-lime glasses were etched using a cw CO_2 laser. We calculated laser induced temperature distributions and compared the results to measurements. The plasma, which is always present whenever there is etching, was diagnosed with spectroscopic and interferometric methods. Information on the plasma temperature and density was obtained for various ambient atmospheres. A density model was derived for a plasma generated in vacuum. The plasma couples with the laser beam resulting in an oscillation during line scan etching. This phenomenon was explained via attenuation of the laser power by the plasma by either absorption, which has been confirmed by direct measurements, or thermal lensing, which was estimated for defocusing of a Gaussian beam by the experimental plasma generated in air or a model plasma in vacuum. The experimental time constant for the oscillation does not appear to be related solely to the thermal time constant of the material. A thermal evaporation etching mechanism is supported by the experimental evidence. Relative etch rates were derived from a steady-state temperature calculation and compared to a typical hole shape obtained experimentally with fairly good agreement. (Copies available exclusively from Micrographics Department, Doheny Library, USC, Los Angeles, CA 90089-0182.).

Hsiao, Kung-Chi

77

Sapphire Fibers for ERBIUM:YAG and Hollow Waveguides for Industrial Carbon Dioxide Laser Power Delivery.  

NASA Astrophysics Data System (ADS)

This work is an investigation of specialty fiber optics for laser power delivery. Solid single-crystal sapphire fibers for the delivery of Er:YAG laser energy were grown using the laser-heated pedestal-growth method. Hollow -sapphire and metal--dielectric-coated hollow-glass waveguides were used to deliver CO_2 laser power for industrial laser applications. Single-crystal sapphire fibers have been grown using the laser-heated pedestal-growth method with losses as low as 0.3 dB/m at 2.94 mum. With the incorporation of a computer-controlled feedback system we have grown fibers with less than +/-0.5% diameter variation, or +/-1.5 mu m for a 300-?m fiber. We have been able to decrease the loss in these fibers through a post-growth anneal at 1000^circ C in air; from 5.4 dB/m to 1.5 dB/m at 543 nm and from 0.4 dB/m to 0.3 dB/m at 2.94 mum. These fibers delivered 4.7 W at 10 Hz of Er:YAG laser power. The loss and output beam properties of our single -crystal sapphire fiber was found to be a function of the Er:YAG laser beam quality. Near single-mode output was obtained from our lowest-loss sapphire fibers with a single -mode input beam. The output was always multimode when the input beam was multimode. Sapphire fibers with a high internal scattering loss had a highly multimode output beam regardless of the input beam quality. Hollow-sapphire and metal--dielectric-coated hollow -glass waveguides have been used to deliver CO_2 laser power for industrial laser applications. The transmission, bending loss, and output-beam properties of these waveguides are described. The bore sizes of the hollow-sapphire waveguides were 1070 and 790 mu m, and the hollow-glass waveguide had a bore of 700 mum. The waveguides ranged in length from 1.1 to 1.5 m. The sapphire waveguides were bent to 90^circ, and the hollow -glass waveguides were bent into a full 360^ circ loop. We delivered a maximum of 1.8 kW through the 1070-mum-bore sapphire waveguide and 1.0 kW through the hollow-glass waveguide. All the hollow waveguides incorporated a water jacket to prevent overheating. Theoretical calculations are presented on the coupling efficiency from multimode industrial CO ^2 lasers to hollow waveguides. To assess the maximum laser power safe for continuous use of these hollow waveguides, theoretical calculations on the temperature distribution with water cooling are also presented.

Nubling, Ricky Kenneth

78

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

NASA Astrophysics Data System (ADS)

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

Taylor, Gregory Stuart

1990-01-01

79

Treatment of split-thickness skin graft-related forearm scar contractures with a carbon dioxide laser protocol: 3 case reports.  

PubMed

Split-thickness skin grafts in the forearm can lead to motion restriction and disability through the dense scarring of the skin and formation of graft-tendon adhesions. Three patients were referred for laser treatment of motion-limiting scar-associated split-thickness skin grafts to theforearm. All patients had reached a plateau in range of motion despite aggressive hand therapy and underwent serial laser scar treatments at 6- to 8-week intervals. Treatments were performed in a clinic setting and were initiated 2 to 5 months after reconstructive surgery. Rapid subjective functional and objective improvements in range of motion were noted after laser therapy. Results were cumulative and durable at final follow-up ranging from 10 to 15months after the initial treatment. No complications were noted. Fractionated carbon dioxide laser therapy is a promising adjunct to hand therapy when the main restraint to motion is superficial skin scarring and skin-tendon adhesions. PMID:24021742

Kroonen, Leo; Shumaker, Peter R; Kwan, Julia M; Uebelhoer, Nathan; Hofmeister, Eric

2013-11-01

80

Molecular Structure of Carbon Dioxide  

NSDL National Science Digital Library

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

2002-08-15

81

Photodynamic Therapy with Ablative Carbon Dioxide Fractional Laser for Treating Bowen Disease  

PubMed Central

Background Topical photodynamic therapy (PDT) has been increasingly used to treat malignant skin tumors including the Bowen disease. However, patients could be displeased with the long incubation time required for conventional PDT. Objective We evaluated the efficacy and safety of PDT with a short incubation time of ablative CO2 fractional laser pretreatment for treating Bowen disease. Methods Ten patients were included. Just before applying the topical photosensitizer, all lesions were treated with ablative CO2 fractional laser, following the application of methyl aminolevulinate and irradiation with red light (Aktilite CL 128). Histological confirmation, rebiopsy, and clinical assessments were performed. Adverse events were also recorded. Results Five of the ten (50%) lesions showed a complete response (CR) within three PDT sessions. After four treatment sessions, all lesions except one penile shaft lesion (90%) achieved clinical and histological CR or clinical CR only. The average number of treatments to CR was 3.701.70. The treatments showed favorable cosmetic outcomes and no serious adverse events. Conclusion The results suggest that pretreatment with an ablative fractional CO2 laser before PDT has similar treatment efficacy and requires a shorter photosensitizer incubation time compared with the conventional PDT method. PMID:24003277

Kim, Sue Kyung; Park, Ji-Youn; Song, Hyo Sang; Kim, You-Sun

2013-01-01

82

Carbon dioxide laser polishing of fused silica surfaces for increased laser-damage resistance at 1064 nm.  

PubMed

Mechanically polished fused silica surfaces were heated with continuous-wave CO(2) laser radiation. Laser-damage thresholds of the surfaces were measured with 1064-nm 9-nsec pulses focused to small spots and with large-spot, 1064-nm, 1-nsec irradiation. A sharp transition from laser-damage-prone to highly laser-damage-resistant took place over a small range in CO(2) laser power. The transition to high damage resistance occurred at a silica surface temperature where material softening began to take place as evidenced by the onset of residual strain in the CO(2) laser-processed part. The small-spot damage measurements show that some CO(2) laser-treated surfaces have a local damage threshold as high as the bulk damage threshold of SiO(2). On some CO(2) laser-treated surfaces, large-spot damage thresholds were increased by a factor of 3-4 over thresholds of the original mechanically polished surface. These treated parts show no obvious change in surface appearance as seen in bright-field, Nomarski, or total internal reflection microscopy. They also show little change in transmissive figure. Further, antireflection films deposited on CO(2) laser-treated surfaces have thresholds greater than the thresholds of antireflection films on mechanically polished surfaces. PMID:20396218

Temple, P A; Lowdermilk, W H; Milam, D

1982-09-15

83

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

SciTech Connect

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

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

2006-04-06

84

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

85

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.

86

Magnesite disposal of carbon dioxide  

SciTech Connect

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

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

1997-08-01

87

Real-time monitoring and adaptive control of carbon dioxide laser beam welding  

NASA Astrophysics Data System (ADS)

Sensor technology has been developed for real-time monitoring and adaptive control of laser beam welding in this work, which include acoustic and optical monitoring of penetration condition of welds, optical measurement of gap width, weld fault detection, as well as adaptive control of beam focal position, beam position on the seam and welding speed. Acoustic sensor is an ordinary condensed microphone. Optical sensor is a unique system of many capabilities that has been developed in this work. With this sensor, a neural fuzzy control system has been designed to improve the control action for these parameter controls. Acoustic monitoring is based on the variation in frequency distribution of the air-borne acoustic signals. Interpretation of the acoustic signals to extract information on weld quality is not straightforward. Three approaches have been proposed to identify the weld using acoustic signals: statistical deviation, statistical pattern recognition and neural network. Each method has shown a certain degree of accuracy of prediction. Optical monitoring is to use the as-developed multi-spot and multi-color detection techique to measure gap width, to detect weld defeats and to identify penetration condition. With optical monitoring, high sampling rate is reached. In weld fault detection, an inverse-filtering algorithm has been developed to successfully resolve information on the weld faults. Closed loop controls of beam focal position, seam tracking and welding speed have been successfully achieved during CO2 laser beam welding experiment. A neural fuzzy control system has been designed for adaptive control of welding speed and seam tracking using optical feedback signals. Simulation results show improvement in control action in comparison to conventional PID controller.

Gu, Hongping

88

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

Microsoft Academic Search

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

Brian James Kirby

2001-01-01

89

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

NASA Technical Reports Server (NTRS)

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

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

2008-01-01

90

Recent progress in development of infrared laser based instruments for real-time ambient measurements of isotopologues of carbon dioxide, water, methane, nitrous oxide and carbon monoxide  

NASA Astrophysics Data System (ADS)

The capacity for real time precise in situ measurements of isotopic ratios of a variety of trace gases at ambient concentrations continues to create new opportunities for the study of the exchanges and fluxes of gases in the environment. Aerodyne Research has made rapid progress in laser based instruments since our introduction in 2007 of the first truly field worthy instrument for real time measurements of isotopologues of carbon dioxide. We have focused on two instrument design platforms, with either one or two lasers. Absorption cells with more than 200 meters path length allow precise measurements of trace gases with low ambient concentrations. Most of our systems employ mid infrared quantum cascade lasers. However, recently available 3 micron antimonide based diode lasers are also proving useful for isotopic measurements. By substituting different lasers and detectors, we can simultaneously measure the isotopic composition of a variety of gases, including: H2O, CO2, CH4, N2O and CO. Our newest instrument for true simultaneous measurement of isotopologues of CO2 (12CO2, 13CO2, 12C18O16O) has (1 s) precision better than 0.1 per mil for both ratios. The availability of 10 Hz measurements allows measurement of isotopic fluxes via eddy correlation. The single laser instrument fits in a 19 inch rack and is only 25 cm tall. A two laser instrument is larger, but with that instrument we can also measure clumped isotopes of CO2, with 1 second precisions of: 2.3 per mil for 13C18O16O, and 6.7 per mil for 13C17O16O. The sample size for such a measurement corresponds to 0.2 micromole of pure CO2. Another variation on the two laser instrument simultaneously measures isotopologues of CO2 (12CO2, 13CO2, 12C18O16O) and H2O (H216O, H218O, HD16O). Preliminary results for water ratio precisions (in 1s) are 0.1 per mil for H218O and 0.3 per mil for HD16O, simultaneous (1 s) precisions for isotopologues of CO2 of ~0.1 per mil. Methane, nitrous oxide and carbon monoxide have such low ambient concentrations that real-time isotopologue measurements are a serious challenge. For these gases, we typically use our 200 m absorption cell. Several of these instruments have already been used for long term field measurements of isotopologues of methane, (12CH4, 13CH4), with a demonstrated (1 s) precision of 1.5 per mil. A new version of this instrument operating near 3.3 microns has recently been developed to quantify 13CH4 and CH3D simultaneously. In separate experiments at MIT, using trapped concentrated samples, we have made highly precise measurements of the abundance of the clumped isotope of methane: 13CH3D. We are also developing methods to monitor the isotopic abundance of the isotopes of CO and N2O. We have achieved a measurement precision for ambient 13CO (1 s) of 1.9 per mil. For the isotopologues of N2O (14N216O, 14N15N 16O, 15N14N 16O, 14N218O), we have demonstrated (1 s) precision at ambient levels (320 ppb) of ~3 per mil. For N2O, a quasi continuous preconcentrator has been used to give even better precisions (<0.1 per mil) and one is being developed for CO.

Nelson, David; McManus, Barry; Shorter, Joanne; Zahniser, Mark; Ono, Shuhei

2014-05-01

91

Carbon Dioxide - Our Common "Enemy"  

NASA Technical Reports Server (NTRS)

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

James, John T.; Macatangay, Ariel

2009-01-01

92

Carbon Dioxide Absorption Heat Pump  

NASA Technical Reports Server (NTRS)

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.

Jones, Jack A. (Inventor)

2002-01-01

93

Enthalpies of dissociation of clathrate hydrates of carbon dioxide, nitrogen, (carbon dioxide + nitrogen), and (carbon dioxide + nitrogen + tetrahydrofuran)  

Microsoft Academic Search

A calorimetric technique is described for measuring the enthalpy of dissociation liberated from solid hydrates. In this study, the enthalpies of dissociation were determined at T= 273.65 K andp= 0.1 MPa for simple and mixed hydrates of carbon dioxide, nitrogen, (carbon dioxide + nitrogen), and (carbon dioxide + nitrogen + tetrahydrofuran) using an isothermal microcalorimeter. The addition of tetrahydrofuran (THF)

B.-J. Ryu

2001-01-01

94

Carbon dioxide transport over complex terrain  

USGS Publications Warehouse

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

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

2004-01-01

95

Nongovernmental valorization of carbon dioxide  

Microsoft Academic Search

Carbon dioxide (CO2) is considered the largest contributor to the greenhouse gas effect. Most attempts to manage the flow of CO2 or carbon into our environment involve reducing net emissions or sequestering the gas into long-lived sinks. Using CO2 as a chemical feedstock has a long history, but using it on scales that might impact the net emissions of CO2

Gene Petersen; Donn Viviani; Kim Magrini-Bair; Stephen Kelley; Luc Moens; Phil Shepherd; Dan DuBois

2005-01-01

96

Geological storage of carbon dioxide  

Microsoft Academic Search

Carbon dioxide is the main compound identified as affecting the stability of the Earth's climate. A significant reduction in the volume of greenhouse gas emissions to the atmosphere is a key mechanism for mitigating against climate change. Geological storage of CO 2, or the injection and stabilization of large volumes of CO 2 in the subsurface in saline aquifers, existing

S. J. Baines; RICHARD H. WORDEN

2004-01-01

97

Efficacy and safety of fractional carbon dioxide laser for treatment of unwanted facial freckles in phototypes II-IV: a pilot study.  

PubMed

Facial freckles are a cosmetic concern to Egyptians, particularly young females. Several therapeutic lines exist with variable response rates and limitations. Fractional carbon dioxide (FCO2) laser provides minimal ablation and therefore less down time and less side effects. The efficacy and safety of this laser technology have still not been studied in freckles. The aim of this study is to assess the efficacy and safety of FCO2 laser in the treatment of unwanted facial freckles in Egyptians. Twenty patients undergone a single session of FCO2 laser and then were followed up clinically a month later. Photographs were taken before treatment and at follow-up visit and were assessed by three blinded investigators. Percent of global improvement was measured on a 4-point grading scale. Patient's satisfaction and adverse events were recorded. Two patients (10%) showed grade 1 improvement, while eight patients (40%) showed grade 2 improvement. Nine patients (45%) showed grade 3 improvement, and only one patient (5%) showed grade 4 improvement. FCO2 laser resurfacing is effective and safe in treatment of facial freckles in skin phototypes II-IV. It can offer a more practical alternative to topical treatments, and a cheaper alternative to Q-switched lasers. PMID:24917080

El Zawahry, Bakr; Zaki, Naglaa; Hafez, Vanessa; Hay, Rania Abdel; Fahim, Aya

2014-11-01

98

2, 18491865, 2005 Carbon dioxide in  

E-print Network

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

Paris-Sud XI, Université de

99

SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW  

E-print Network

SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW J. E. Santos1, G. B. Savioli2, J. M. Carcione3, D´e, 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

Santos, Juan

100

SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW  

E-print Network

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

Santos, Juan

101

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

102

21 CFR 184.1240 - Carbon dioxide.  

...2014-04-01 2014-04-01 false Carbon dioxide. 184.1240 Section 184.1240 Food and Drugs...Substances Affirmed as GRAS 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2 , CAS Reg. No....

2014-04-01

103

Water vapor and carbon dioxide species measurements in narrow channels  

Microsoft Academic Search

Classical spectroscopic techniques have been applied in a novel manner to measure the concentration of gas species, water vapor and carbon dioxide, within a narrow channel flow field non-invasively. Tunable diode laser absorption spectroscopy (TDLAS) was used in conjunction with a laser modulated at a high frequency [Wavelength Modulation Spectroscopy (WMS)] tuned to the ro-vibrational transition of the species. This

Saptarshi Basu; Derek E. Lambe; Ranganathan Kumar

2010-01-01

104

The Impact of Carbon Dioxide on Climate.  

ERIC Educational Resources Information Center

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

MacDonald, Gordon J.

1979-01-01

105

Oxygen and carbon dioxide sensing  

NASA Technical Reports Server (NTRS)

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

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

2012-01-01

106

Sonochemical reduction of carbon dioxide  

Microsoft Academic Search

Sonolysis of carbon dioxide dissolved in water was performed from a standpoint of reducing this material in atmosphere. During one hour of sonication, the amount of CO2 decreased to about half at 5C under CO2Ar atmosphere. The decreasing rate for CO2 followed the order Ar>He>H2>N2 and it was down with increasing temperature in the range of 545C. The most favorable

Hisashi Harada

1998-01-01

107

Interpreting recent carbon dioxide data  

NSDL National Science Digital Library

Using web-accessed climate data, students will examine the latitudinal distribution of CO2 and explain how (and why) that has changed over (recent) time. They will then work in groups of two or three to download, graph, and interpret carbon dioxide concentration data from one individual location (different groups will be assigned a different site). Each student will complete a series of questions to ensure their understanding of the concepts outlined above.

Gordon, Elizabeth

108

Carbon Dioxide Removal via Passive Thermal Approaches  

NASA Technical Reports Server (NTRS)

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

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

2011-01-01

109

Thermodynamic Promotion of Carbon Dioxide Clathrate Hydrate Formation by  

E-print Network

Thermodynamic Promotion of Carbon Dioxide Clathrate Hydrate Formation by Tetrahydrofuran, Cyclopentane)-vapour (V) equilibrium pressures for the ternary system composed of water, tetrahydrofuran (THF), and carbon and carbon dioxide. Keywords: Gas Hydrates, carbon dioxide capture, tetrahydrofuran, cyclopentane

Paris-Sud XI, Université de

110

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

111

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.

112

Effect of Carbon Dioxide Variations on Climate  

Microsoft Academic Search

Variations in the amount of atmospheric carbon dioxide cause temperature changes sufficiently large to influence the climate. If the atmospheric carbon dioxide doubles, the surface temperature rises 3.6C if it is cut in half, the surface temperature falls 3.8C. Some of the factors that can be explained by the carbon dioxide theory are: during a single glacial epoch, the climate

Gilbert N. Plass

1956-01-01

113

Carbon dioxide and intergenerational choice  

SciTech Connect

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

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

1982-05-01

114

Carbon dioxide sequestration as stable carbonate minerals - environmental barriers  

Microsoft Academic Search

This paper considers the major environmental impacts associated with industrial-scale carbon dioxide sequestration as stable carbonate minerals, material resulting from a study undertaken by CSMA Consultants Ltd. in 1999. The chemical bonding of carbon dioxide, through reaction of two or more products to produce magnesium or calcium carbonate has been suggested as a means to mitigate CO2 from fossil fuel

H. Haywood; J. Eyre; H. Scholes

2001-01-01

115

46 CFR 169.565 - Fixed carbon dioxide system.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565...Firefighting Equipment 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space protected...

2013-10-01

116

46 CFR 95.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Carbon dioxide storage. 95.15-20 Section 95...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details 95.15-20 Carbon dioxide storage. (a) Except as...

2013-10-01

117

21 CFR 868.5310 - Carbon dioxide absorber.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Carbon dioxide absorber. 868.5310 Section 868...Therapeutic Devices 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is...

2012-04-01

118

46 CFR 76.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Carbon dioxide storage. 76.15-20 Section 76...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details 76.15-20 Carbon dioxide storage. (a) Except as...

2011-10-01

119

46 CFR 97.37-9 - Carbon dioxide alarm.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9...Emergency Equipment, Etc. 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified:...

2010-10-01

120

21 CFR 868.1400 - Carbon dioxide gas analyzer.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...Diagnostic Devices 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to...

2012-04-01

121

46 CFR 95.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Carbon dioxide storage. 95.15-20 Section 95...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details 95.15-20 Carbon dioxide storage. (a) Except as...

2011-10-01

122

21 CFR 868.5300 - Carbon dioxide absorbent.  

...2014-04-01 2014-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...Therapeutic Devices 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for...

2014-04-01

123

40 CFR 86.524-78 - Carbon dioxide analyzer calibration.  

...2014-07-01 2014-07-01 false Carbon dioxide analyzer calibration. 86.524-78...Procedures 86.524-78 Carbon dioxide analyzer calibration. (a) Prior...and monthly thereafter the NDIR carbon dioxide analyzer shall be calibrated:...

2014-07-01

124

21 CFR 868.5310 - Carbon dioxide absorber.  

...2014-04-01 2014-04-01 false Carbon dioxide absorber. 868.5310 Section 868...Therapeutic Devices 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is...

2014-04-01

125

21 CFR 868.1400 - Carbon dioxide gas analyzer.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...Diagnostic Devices 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to...

2013-04-01

126

46 CFR 108.626 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Carbon dioxide warning signs. 108.626 Section...and Instructions 108.626 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by...

2013-10-01

127

46 CFR 108.431 - Carbon dioxide systems: General.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Carbon dioxide systems: General. 108.431 Section...Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems 108.431 Carbon dioxide systems: General. (a)...

2011-10-01

128

46 CFR 108.431 - Carbon dioxide systems: General.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Carbon dioxide systems: General. 108.431 Section...Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems 108.431 Carbon dioxide systems: General. (a)...

2012-10-01

129

46 CFR 97.37-9 - Carbon dioxide alarm.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9...Emergency Equipment, Etc. 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified:...

2011-10-01

130

21 CFR 868.5300 - Carbon dioxide absorbent.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...Therapeutic Devices 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for...

2013-04-01

131

46 CFR 76.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Carbon dioxide storage. 76.15-20 Section 76...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details 76.15-20 Carbon dioxide storage. (a) Except as...

2013-10-01

132

46 CFR 108.431 - Carbon dioxide systems: General.  

Code of Federal Regulations, 2013 CFR

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

2013-10-01

133

46 CFR 108.431 - Carbon dioxide systems: General.  

Code of Federal Regulations, 2010 CFR

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

2010-10-01

134

21 CFR 868.5310 - Carbon dioxide absorber.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Carbon dioxide absorber. 868.5310 Section 868...Therapeutic Devices 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is...

2011-04-01

135

46 CFR 108.626 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Carbon dioxide warning signs. 108.626 Section...and Instructions 108.626 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by...

2012-10-01

136

46 CFR 76.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Carbon dioxide storage. 76.15-20 Section 76...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details 76.15-20 Carbon dioxide storage. (a) Except as...

2012-10-01

137

21 CFR 868.5300 - Carbon dioxide absorbent.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...Therapeutic Devices 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for...

2012-04-01

138

46 CFR 95.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Carbon dioxide storage. 95.15-20 Section 95...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details 95.15-20 Carbon dioxide storage. (a) Except as...

2012-10-01

139

21 CFR 868.5300 - Carbon dioxide absorbent.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...Therapeutic Devices 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for...

2011-04-01

140

21 CFR 868.5310 - Carbon dioxide absorber.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Carbon dioxide absorber. 868.5310 Section 868...Therapeutic Devices 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is...

2013-04-01

141

46 CFR 193.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Carbon dioxide storage. 193.15-20 Section 193...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details 193.15-20 Carbon dioxide storage. (a) Except as...

2011-10-01

142

46 CFR 169.565 - Fixed carbon dioxide system.  

Code of Federal Regulations, 2012 CFR

... 2012-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565...Firefighting Equipment 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space protected...

2012-10-01

143

Carbon Dioxide for pH Control  

SciTech Connect

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

Wagonner, R.C.

2001-08-16

144

A new look at atmospheric carbon dioxide  

Microsoft Academic Search

Carbon dioxide is increasing in the atmosphere and is of considerable concern in global climate change because of its greenhouse gas warming potential. The rate of increase has accelerated since measurements began at Mauna Loa Observatory in 1958 where carbon dioxide increased from less than 1 part per million per year (ppmyr?1) prior to 1970 to more than 2ppmyr?1 in

David J. Hofmann; James H. Butler; Pieter P. Tans

2009-01-01

145

Residential carbon dioxide emissions in Canada  

Microsoft Academic Search

The effect of improving house envelope, heating system and appliance efficiencies, and fuel substitution on the atmospheric emissions of carbon dioxide in the Canadian residential sector is studied based on simulation studies. The findings clearly indicate that improving appliance efficiency reduces the overall end-use energy consumption in the residential sector as well as the associated carbon dioxide emissions. However, the

V. Ismet Ugursal; Alan S. Fung

1998-01-01

146

Interglacials, Milankovitch Cycles, and Carbon Dioxide  

E-print Network

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

Marsh, Gerald E

2010-01-01

147

Interglacials, Milankovitch Cycles, and Carbon Dioxide  

E-print Network

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

Gerald E. Marsh

2010-02-02

148

New Method for Isotopic Ratio Measurements of Atmospheric Carbon Dioxide Using a 4.3 m Pulsed Quantum Cascade  

E-print Network

1 New Method for Isotopic Ratio Measurements of Atmospheric Carbon Dioxide Using a 4.3 µm Pulsed of stable isotopic ratios of carbon dioxide using a near room temperature pulsed quantum cascade laser; 91.67.Rx 1. Introduction Real time methods to monitor the stable isotopic ratios of carbon dioxide

Saleska, Scott

149

Microfluidic studies of carbon dioxide.  

PubMed

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

Abolhasani, Milad; Gnther, Axel; Kumacheva, Eugenia

2014-07-28

150

Carbon dioxide capture process with regenerable sorbents  

DOEpatents

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

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

2002-05-14

151

SEQUESTERING CARBON DIOXIDE IN COALBEDS  

SciTech Connect

During the present reporting period, six complementary tasks involving experimentation, model development, and coal characterization were undertaken to meet our project objectives: (1) A second adsorption apparatus, utilizing equipment donated by BP Amoco, was assembled. Having confirmed the reliability of this additional experimental apparatus and procedures, adsorption isotherms for CO{sub 2}, methane, ethane, and nitrogen on wet Fruitland coal and on activated carbon were measured at 319.3 K (115 F) and pressures to 12.4 MPa (1800 psia). These measurements showed good agreement with our previous data and yielded an expected uncertainty of about 3%. The addition of this new facility has allowed us to essentially double our rate of data production. (2) Adsorption isotherms for pure CO{sub 2}, methane, and nitrogen on wet Illinois-6 coal and on activated carbon were measured at 319.3 K (115 F) and pressures to 12.4 MPa (1800 psia) on our first apparatus. The activated carbon measurements showed good agreement with literature data and with measurements obtained on our second apparatus. The expected uncertainty of the data is about 3%. The Illinois-6 adsorption measurements are a new addition to the existing database. Preparations are underway to measure adsorption isotherms for pure methane, carbon dioxide and nitrogen on DESC-8 coal. (3) Adsorption from binary mixtures of methane, nitrogen and CO{sub 2} at a series of compositions was also measured on the wet Fruitland coal at 319.3 K (115 F), using our first apparatus. The nominal compositions of these mixtures are 20%/80%, 40%/60%, 60%/40%, and 80%/20%. The experiments were conducted at pressures from 100 psia to 1800 psia. The expected uncertainty for these binary mixture data varies from 2 to 9%. (4) A study was completed to address the previously-reported rise in the CO{sub 2} absolute adsorption on wet Fruitland coal at 115 F and pressures exceeding 1200 psia. Our additional adsorption measurements on Fruitland coal and on activated carbon show that: (a) the Gibbs adsorption isotherm for CO{sub 2} under study exhibits typical adsorption behavior for supercritical gas adsorption, and (b) a slight variation from Type I absolute adsorption may be observed for CO{sub 2}, but the variation is sensitive to the estimates used for adsorbed phase density. (5) The experimental data were used to evaluate the predictive capabilities of various adsorption models, including the Langmuir/loading ratio correlation, a two-dimensional cubic equation of state (EOS), a new two-dimensional (2-D) segment-segment interactions equation of state, and the simplified local density model (SLD). Our model development efforts have focused on developing the 2-D analog to the Park-Gasem-Robinson (PGR) EOS and an improved form of the SLD model. The new PGR EOS offers two advantages: (a) it has a more accurate repulsive term, which is important for reliable adsorption predictions, and (b) it is a segment-segment interactions model, which should more closely describe the gas-coal interactions during the adsorption process. In addition, a slit form of the SLD model was refined to account more precisely for heterogeneity of the coal surface and matrix swelling. In general, all models performed well for the Type I adsorption exhibited by methane, nitrogen, and carbon dioxide up to 8.3 MPa (average deviations within 2%). In comparison, the SLD model represented the adsorption behavior of all fluids considered within 5% average deviations, including the near-critical behavior of carbon dioxide beyond 8.3 MPa (1200 psia). Work is in progress to (a) derive and implement the biporous form of the SLD model, which would expand the number of structural geometries used to represent the heterogeneity of coal surface; and (b) extend the SLD model to mixture predictions. (6) Proper reduction of our adsorption data requires accurate gas-phase compressibility (Z) factors for methane, ethane, nitrogen and carbon dioxide and their mixtures to properly analyze our experimental adsorption data. A careful evaluation of t

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

2001-06-15

152

Photolytical Generation of Carbon Dioxide  

NASA Astrophysics Data System (ADS)

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

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

2008-12-01

153

Uncertainty analysis for the miniaturized laser heterodyne radiometer (mini-LHR) for the measurement of carbon dioxide in the atmospheric column  

NASA Astrophysics Data System (ADS)

Presented here is a sensitivity analysis for the miniaturized laser heterodyne radiometer. This passive, ground-based instrument measures carbon dioxide (CO2) in the atmospheric column and has been under development at NASA/GSFC since 2009. The goal of this development is to produce a low-cost, easily-deployable instrument that can extend current ground measurement networks in order to (1) validate column satellite observations, (2) provide coverage in regions of limited satellite observations, (3) target regions of interest such as thawing permafrost, and (4) support the continuity of a long-term climate record. In this paper an uncertainty analysis of the instrument performance is presented and compared with results from three sets of field measurements. The signal-to-noise ratio (SNR) and corresponding maximum uncertainty for a single scan are calculated to be 329.4 1.3 by deploying error propagation through the equation governing the SNR. Reported is an absorbance noise of 0.0024 for six averaged scans of field data, for an instrument precision of 0.14 ppmv for CO2.

Clarke, G. B.; Wilson, E. L.; Miller, J. H.; Melroy, H. R.

2014-05-01

154

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

PubMed Central

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

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

2013-01-01

155

Carbon dioxide sequestration as stable carbonate minerals - environmental barriers  

NASA Astrophysics Data System (ADS)

This paper considers the major environmental impacts associated with industrial-scale carbon dioxide sequestration as stable carbonate minerals, material resulting from a study undertaken by CSMA Consultants Ltd. in 1999. The chemical bonding of carbon dioxide, through reaction of two or more products to produce magnesium or calcium carbonate has been suggested as a means to mitigate CO2 from fossil fuel power plants. The study considered six potential methods for sequestering carbon dioxide, notionally captured from fossil fuel burning power stations, as stable mineral carbonates, i.e. magnesite and limestone (calcium carbonate) and as sodium bicarbonate. Four methods were eliminated in the initial screening and two were selected for further detailed consideration. Following this stage the overall environmental costs, including environmental impacts, energy and carbon dioxide balances, meant that all the current technologies amenable to reasoned consideration had to be discarded as currently environmentally unacceptable.

Haywood, H.; Eyre, J.; Scholes, H.

2001-11-01

156

Carbon dioxide emission scenarios: limitations of the fossil fuel resource  

Microsoft Academic Search

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)

Christopher Vernon; Erica Thompson; Sarah Cornell

2011-01-01

157

Atmospheric Lifetime of Fossil Fuel Carbon Dioxide  

E-print Network

Atmospheric Lifetime of Fossil Fuel Carbon Dioxide David Archer,1 Michael Eby,2 Victor Brovkin,3 released from combustion of fossil fuels equilibrates among the various carbon reservoirs of the atmosphere 0084-6597/09/0530-0117$20.00 Key Words climate, warming, ocean chemistry, carbon cycle Abstract CO2

Scherer, Norbert F.

158

Carbon Dioxide Emission Factors for Coal  

EIA Publications

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

1994-01-01

159

Regulating carbon dioxide capture and storage  

E-print Network

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 ...

De Figueiredo, Mark A.

2007-01-01

160

Role of activated carbon pellets in carbon dioxide removal  

Microsoft Academic Search

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

S. C Sarkar; A Bose

1997-01-01

161

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

Microsoft Academic Search

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

K. Mundra; T. Debroy

1993-01-01

162

Zinc-catalyzed copolymerization of carbon dioxide and propylene oxide  

E-print Network

The zinc-catalyzed copolymerization of carbon dioxide and propylene oxide, which is one of the promising reactions for the utilization of carbon dioxide, has been investigated from various aspects. Above all, considering that supercritical carbon...

Katsurao, Takumi

2012-06-07

163

Education, Convergence and Carbon Dioxide Growth per Capita  

E-print Network

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

Paris-Sud XI, Université de

164

Turning carbon dioxide into fuel.  

PubMed

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

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

2010-07-28

165

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

E-print Network

(for water: the SPC-, SPC/E-, and TIP4P-potential models; for carbon dioxide: the EPM2 potential model. The interactions between carbon dioxide and water were estimated from the pair potentials of the pure components of intermolecular pair potentials for various substances is documented. Especially water has been the subject

166

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

NASA Astrophysics Data System (ADS)

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

Urru, Giovanni; Moretti, Gianfranco

1998-01-01

167

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.

168

Atmospheric Lifetime of Fossil Fuel Carbon Dioxide  

E-print Network

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

Matsumoto, Katsumi

169

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.

170

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

Microsoft Academic Search

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

Norman H. Hagedorn

1991-01-01

171

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

Microsoft Academic Search

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

Norman H. Hagedorn

1993-01-01

172

Method for extracting and sequestering carbon dioxide  

DOEpatents

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

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

2005-05-10

173

Apparatus for extracting and sequestering carbon dioxide  

DOEpatents

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

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

2010-02-02

174

SEQUESTERING CARBON DIOXIDE IN COALBEDS  

SciTech Connect

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

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

2003-03-10

175

SEQUESTERING CARBON DIOXIDE IN COALBEDS  

SciTech Connect

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

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

2003-04-30

176

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)

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.

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

2013-04-01

177

Carbon Dioxide Fluxes in the Global Ocean  

Microsoft Academic Search

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

Andrew J. Watson; James C. Orr

178

Global deforestation: contribution to atmospheric carbon dioxide  

Microsoft Academic Search

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

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

1983-01-01

179

Designed amyloid fibers as materials for selective carbon dioxide capture  

PubMed Central

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

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

2014-01-01

180

Ecosystem Fluxes of Stable Isotopes in Carbon Dioxide and Water Vapor Above a Forest Measured by Laser Spectroscopy  

NASA Astrophysics Data System (ADS)

Eddy covariance or flux gradient measurement of stable isotopes in CO2 and H2O would provide a direct measure of ecosystem discrimination and thus indicate the ecosystem fingerprint on the atmosphere's isotopic budget. Eddy covariance measurements of stable isotopes require, however, high-precision and very fast instruments, which are available only since very recently. We use a quantum cascade laser absorption spectrometer (Aerodyne Research Inc.) for the simultaneous measurement of 16O12C16O, 16O13C16O and 18O12C16O isotopologues with a sampling rate of up to 10 Hz. The 1-sec precision for both ?13C and ?18O in CO2 is about 0.20. Hourly calibrations are performed with two calibration gases and by dynamically diluting a third calibration gas with CO2-free air. The long-term stability was assessed with repeated measurements of a quality control standard. The 1-? standard deviation of these measurements over a time period of three weeks was 0.15 for both ?13C and ?18O. Using a second laser spectrometer, isotopologues of water vapor (1H16O1H, 1H18O1H and 2H16O1H) are measured at a sampling rate of 0.5 Hz by Off-Axis Integrated Cavity Output Spectroscopy (Los Gatos Research Inc.). The 2-sec precisions of ?2H and ?18O in water vapor are about 1.0 and 0.3, respectively. A custom made dripping device based on ink jet technology is used to calibrate the isotopic measurements of water vapor. We present the first eddy covariance flux measurements of the stable CO2 isotopologues above a forest ecosystem and assess the feasibility to infer ecosystem discrimination from such measurements. Cospectral analysis of vertical wind speed and the isotopologue mixing ratios show the expected inertial sub- range behavior matching well CO2 measurements with an open-path gas analyzer (LI-7500, Li-Cor Inc.), but also show some dampening in the 0.5-5 Hz range due to tube attenuation. The concurrent measurements of ?2H and ?18O in water vapor show large diurnal and day-to-day variability, but little vertical variation within the canopy indicating strong vertical mixing.

Sturm, P.; Barthel, M.; Etzold, S.; Eugster, W.; Gentsch, L.; Zeeman, M.; Knohl, A.

2008-12-01

181

Preliminary report on the use of a carbon dioxide laser for palmar digital neurectomy in the horse  

NASA Astrophysics Data System (ADS)

Digital nerve samples obtained from horses using a CO2 laser for surgical excision at various power densities in both continuous wave (CW) and superpulse (SP) modes were examined histologically and using a scanning electron microscope. Preliminary data suggest that the lowest power density examined (637 W/cm2) in CW mode provided a wide zone of thermal change and the best tissue coagulation. Power densities of 15,924 and 31,847 W/cm2 SP mode showed a narrower zone of thermal change, and a coagulated but much more disrupted excisional surface than that which was observed at lower power densities, or at the same power densities where CW mode was used. Clinical trials where equine palmer digital neurectomies have been done at 637 W/cm2 (5 W, 1.0 mm spot size) CW and at 47,771 W/cm2 (15 W, 0.2 mm spot size) SP have not been completed at this time. It has been observed that attempting the surgical procedure at 127,388 W/cm2 (40 W, 0.2 mm spot size) CW was difficult for the surgeon to control and resulted in marked post surgical discomfort of the patient. For these reasons we eliminated power densities above 63,694 (20 W, 0.2 mm spot size) from our neurectomy studies.

Peavy, George M.; Liaw, Lih-Huei L.; Fischer, A. T.; Williams, John W.; Pankowski, Richard; Berns, Michael W.

1992-06-01

182

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

SciTech Connect

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

Thomason, M.D.

1982-07-01

183

Carbon dioxide hydrate and floods on Mars  

NASA Technical Reports Server (NTRS)

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

Milton, D. J.

1974-01-01

184

Carbon dioxide opacity of the Venus' atmosphere  

NASA Astrophysics Data System (ADS)

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.

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

2014-11-01

185

Carbon Dioxide Fixation in Cultured Animal Cells  

E-print Network

H the activity of adenosine tri phosphatase was Increased by carbon dioxide. Also, the same investigators found that increasing the carbon dioxide concentration from 10 to 1*0 mM at constant pH stimulated the conversion of acetate into fatty acids four to six... and Cortisol were present to gether (I9li, 70 ) . Paradoxically, tryptophan and quinolinic acid increased the in vitro assayable activity of PEP-CK (259, 68). Upon extraction, the inhibition appears to dissociate from the enzyme, leaving it in a metal...

Kyner, David Smith

1969-01-01

186

Global deforestation: contribution to atmospheric carbon dioxide  

SciTech Connect

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

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

1983-12-09

187

Oxygen Atom Recombination in Carbon Dioxide Atmospheres  

NASA Astrophysics Data System (ADS)

Understanding processes involving atomic oxygen is crucial for the study and modeling of composition, energy transfer, airglow, and transport dynamics in planetary atmospheres. Significant gaps and uncertainties exist in our understanding of the above processes, and often the relevant input from laboratory measurements is missing or outdated. We are conducting experiments to measure the rate coefficients for O + O + CO2 and O + O2 + CO2 recombination and investigate the O2 excited states produced following O-atom recombination. These laboratory measurements are key input for a quantitative understanding and reliable modeling of the atmospheres of the CO2 planets and their airglow. An ArF excimer laser with 193-nm pulsed output radiation is employed to partially photodissociate carbon dioxide. In an ambient-pressure (760 Torr) background of CO2, the O atoms produced recombine in a time scale of a few milliseconds. Detection of laser-induced fluorescence at 845 nm following two-photon excitation near 226 nm monitors the decay of the oxygen atom population. From the temporal evolution of the signal we can extract the rate coefficients for recombination of O + O and O + O2 in the presence of CO2. We also use fluorescence and resonance-enhanced multi-photon ionization techniques to detect the products of the O-atom recombination and subsequent relaxation in CO2. This work is supported by the US National Science Foundation's (NSF) Planetary Astronomy Program. Rosanne Garcia's participation was funded by the NSF Research Experiences for Undergraduates (REU) Program.

Jamieson, Corey; Garcia, R. M.; Pejakovic, D. A.; Kalogerakis, K. S.

2009-09-01

188

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

Microsoft Academic Search

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

G. J. Fergusson

1958-01-01

189

Electroreduction of carbon dioxide in aqueous solutions at metal electrodes  

Microsoft Academic Search

The quantities of carbon stored in the form of atmospheric carbon dioxide, CO in the hydrosphere and carbonates in the terrestrial environment substantially exceed those of fossil fuels. In spite of this the industrial use of carbon dioxide as a source of chemical carbon is presently limited to preparation of urea and certain carboxylic acids as well as organic carbonates

J. Augustynski; B. Jermann; P. Kedzierzawski

1996-01-01

190

Organic syntheses employing supercritical carbon dioxide as a reaction solvent  

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

191

Organic syntheses employing supercritical carbon dioxide as a reaction solvent  

NASA Technical Reports Server (NTRS)

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

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

1991-01-01

192

Gas diffusion cell removes carbon dioxide from occupied airtight enclosures  

NASA Technical Reports Server (NTRS)

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.

1964-01-01

193

International Space Station Carbon Dioxide Removal Assembly Testing  

NASA Technical Reports Server (NTRS)

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

Knox, James C.

2000-01-01

194

Demonstration of a Carbon Dioxide-Based Industrial Laundry Machine  

E-print Network

Demonstration of a Carbon Dioxide- Based Industrial Laundry Machine Industrial cleaning and disinfection machine must be demonstrated with independent verification commercial supercritical-carbon dioxide textile cleaning machine to document and validate: Real

195

40 CFR 86.1524 - Carbon dioxide analyzer calibration.  

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

2014-07-01

196

The urgent need for carbon dioxide sequestration  

SciTech Connect

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

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

1998-09-01

197

U.S. Energy-Related Carbon Dioxide Emissions  

EIA Publications

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

2013-01-01

198

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

Microsoft Academic Search

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

Folke Bohlin

1998-01-01

199

Carbon Dioxide Production at Home  

NSDL National Science Digital Library

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

200

Carbon Dioxide Capture from Coal-Fired  

E-print Network

Carbon Dioxide Capture from Coal-Fired Power Plants: A Real Options Analysis May 2005 MIT LFEE 2005. LFEE 2005-002 Report #12;#12;i ABSTRACT Investments in three coal-fired power generation technologies environment. The technologies evaluated are pulverized coal (PC), integrated coal gasification combined cycle

201

DIETHANOLAMINE-CARBON DIOXIDE BUFFER PRODUCES ETHYLENE  

EPA Science Inventory

Carbon dioxide concentrates in containers are frequently controlled by using a diethanolamine-bicarbonate buffer. Current studies show that this buffer produces ethylene and that the production increases with increasing pH and/or time in the incubation vessel. Ethylene is not pro...

202

Recent Events: a Perspective on Carbon Dioxide  

NSDL National Science Digital Library

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

203

Carbon dioxide enhances fragility of ice crystals  

NASA Astrophysics Data System (ADS)

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

Qin, Zhao; Buehler, Markus J.

2012-11-01

204

Synthetic fuels, carbon dioxide and climate  

Microsoft Academic Search

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

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

1982-01-01

205

Synthetic fuels, carbon dioxide and climate  

Microsoft Academic Search

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

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

1982-01-01

206

Enriched oil recovery using carbon dioxide  

Microsoft Academic Search

A single cell protein plant is operated to produce high density cell growth and a substantially pure stream of generally high pressure carbon dioxide for further use, for example, in enhanced oil recovery operations. The plant employs an air separator producing substantially pure streams of oxygen and nitrogen. The oxygen stream is used to enrich a carrier fluid and used

Hitzman

1981-01-01

207

Carbon Dioxide Separation Using Thermally Optimized Membranes  

Microsoft Academic Search

The purpose of this project is to develop polymeric-metallic membranes for carbon dioxide separations that operate under a broad range of industrially relevant conditions not accessible with present membrane units. The last decade has witnessed a dramatic increase in the use of polymer membranes as an effective, economic and flexible tool for many commercial gas separations including air separation, the

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

2002-01-01

208

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.

209

World Electricity Consumption and Carbon Dioxide  

NSDL National Science Digital Library

In this problem set, learners will analyze a table of global electricity consumption to answer a series of questions and consider the production of carbon dioxide associated with that consumption. Answer key is provided. This is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

210

Acid sorption regeneration process using carbon dioxide  

DOEpatents

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.

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

2001-01-01

211

Carbon dioxide hydrationand dehydration kinetics in seawater  

Microsoft Academic Search

Rate constants for the hydration and dehydration reactions of carbon dioxide with water and with hydroxyl ion were measured in seawater by a pH-stat method at salinities (X lO:l) from 3.4 to 37.06 at 25C and from 5\\

Kenneth S. Johnson

1982-01-01

212

Photobiological hydrogen production and carbon dioxide sequestration  

Microsoft Academic Search

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

Halil Berberoglu

2008-01-01

213

Carbon dioxide on the early earth  

Microsoft Academic Search

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

J. C. G. Walker

1985-01-01

214

The urgent need for carbon dioxide sequestration  

Microsoft Academic Search

The danger of global warming has put in question the use of fossil fuels which constitute the most abundant and most reliable energy resource. Meeting the ever growing world demand for cheap energy, while simultaneously achieving the required drastic reduction in CO emissions can only be accomplished by actively preventing carbon dioxide generated in the combustion of fuels from accumulating

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

1998-01-01

215

40 CFR 86.124-78 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2011 CFR

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

2011-07-01

216

40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

217

40 CFR 86.124-78 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

218

40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2011 CFR

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

2011-07-01

219

Method of immobilizing carbon dioxide from gas streams  

Microsoft Academic Search

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

David W. Holladay; Gary L. Haag

1979-01-01

220

Method of immobilizing carbon dioxide from gas streams  

Microsoft Academic Search

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

D. W. Holladay; G. L. Haag

1979-01-01

221

Inhibition of chlorophyll synthesis by high concentrations of carbon dioxide  

Microsoft Academic Search

High concentrations of carbon dioxide inhibit the greening of etiolated plants. In the presence of 20% oxygen, concentrations of carbon dioxide of 10% and above inhibited the production of chlorophyll in etiolated leaves of barley, wheat, and dwarf French bean. On return to air, recovery from this inhibition took place rapidly. High concentrations of carbon dioxide were also inhibitory when

B. T. Steer; D. A. Walker

1964-01-01

222

ORNL/CDIAC-34 Carbon Dioxide Information Analysis Center and  

E-print Network

ORNL/CDIAC-34 May 1999 Carbon Dioxide Information Analysis Center and World Data Center Carbon Dioxide Information Analysis Center (423) 574-3645 Oak Ridge National Laboratory URL: http 37831-6335 FTP: cdiac.esd.ornl.gov #12;ORNL/CDIAC-34 May 1999 Carbon Dioxide Information Analysis Center

223

Chukwuemeka I. Okoye Carbon Dioxide Solubility and Absorption Rate in  

E-print Network

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

Rochelle, Gary T.

224

High Temperature Electrolysis of Steam and Carbon Dioxide  

E-print Network

High Temperature Electrolysis of Steam and Carbon Dioxide S�ren H�jgaard Jensen+,#, Jens V. T. H (ASR) #12;Electrolysis of carbon dioxide and steam CO2 + H2O H2 + CO + 3/2 O2 Interesting because of electrolysis of steam and carbon dioxide Picture taken from J. R. Rostrup, Steam Reforming and Catalysts

225

46 CFR 97.37-11 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Carbon dioxide warning signs. 97.37-11 Section...Equipment, Etc. 97.37-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by...

2013-10-01

226

www.sciam.com SCIENTIFIC AMERICAN 49 Pumping carbon dioxide  

E-print Network

www.sciam.com SCIENTIFIC AMERICAN 49 CREDIT CanWe Bury GLOBAL WARMING? Pumping carbon dioxide his lungs were carbon dioxide. Each time you draw breath today, 380 mole- cules per million are carbon dioxide. That portion climbs about two mole- cules every year. No one knows the exact consequenc- es

O'Donnell, Tom

227

40 CFR 86.124-78 - Carbon dioxide analyzer calibration.  

...2014-07-01 2014-07-01 false Carbon dioxide analyzer calibration. 86.124-78...Procedures 86.124-78 Carbon dioxide analyzer calibration. Prior to its...and monthly thereafter the NDIR carbon dioxide analyzer shall be calibrated:...

2014-07-01

228

46 CFR 196.37-8 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Carbon dioxide warning signs. 196.37-8 Section...Equipment, etc. 196.37-8 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by...

2012-10-01

229

46 CFR 78.47-11 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Carbon dioxide warning signs. 78.47-11 Section...Equipment, Etc. 78.47-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by...

2012-10-01

230

Irreversible climate change due to carbon dioxide emissions  

E-print Network

Irreversible climate change due to carbon dioxide emissions Susan Solomona,1 , Gian in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop. Following cessation of emissions, removal of atmospheric carbon dioxide decreases radiative forcing, but is largely

Fischlin, Andreas

231

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

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

2014-10-01

232

40 CFR 89.322 - Carbon dioxide analyzer calibration.  

...2014-07-01 2013-07-01 true Carbon dioxide analyzer calibration. 89.322 Section...Equipment Provisions 89.322 Carbon dioxide analyzer calibration. (a) Prior...bi-monthly thereafter, the NDIR carbon dioxide analyzer shall be calibrated on...

2014-07-01

233

46 CFR 196.37-8 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Carbon dioxide warning signs. 196.37-8 Section...Equipment, etc. 196.37-8 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by...

2013-10-01

234

40 CFR 91.320 - Carbon dioxide analyzer calibration.  

...2014-07-01 2013-07-01 true Carbon dioxide analyzer calibration. 91.320 Section...Equipment Provisions 91.320 Carbon dioxide analyzer calibration. (a) Prior...certification test, calibrate the NDIR carbon dioxide analyzer as follows: (1)...

2014-07-01

235

46 CFR 78.47-11 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Carbon dioxide warning signs. 78.47-11 Section...Equipment, Etc. 78.47-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by...

2013-10-01

236

46 CFR 97.37-11 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Carbon dioxide warning signs. 97.37-11 Section...Equipment, Etc. 97.37-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by...

2012-10-01

237

40 CFR 90.320 - Carbon dioxide analyzer calibration.  

...2014-07-01 2013-07-01 true Carbon dioxide analyzer calibration. 90.320 Section...Equipment Provisions 90.320 Carbon dioxide analyzer calibration. (a) Prior...certification test, calibrate the NDIR carbon dioxide analyzer as follows: (1)...

2014-07-01

238

Catalyst cartridge for carbon dioxide reduction unit  

NASA Technical Reports Server (NTRS)

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.

Holmes, R. F. (inventor)

1973-01-01

239

Carbon Dioxide Snow Storms During the Polar Night on Mars  

NASA Technical Reports Server (NTRS)

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

Toon, Owen B.; Colaprete, Anthony

2001-01-01

240

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

E-print Network

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

Huppert, Herbert

241

Ocean uptake of carbon dioxide  

SciTech Connect

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

Peng, Tsung-Hung (Oak Ridge National Lab., TN (United States)); Takahashi, Taro (Columbia Univ., Palisades, NY (United States). Lamont-Doherty Earth Observatory)

1993-01-01

242

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

Microsoft Academic Search

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

M. Hasebe; Y. Suzuki

2003-01-01

243

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

NSDL National Science Digital Library

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

Pratte, John

244

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

NASA Astrophysics Data System (ADS)

The ratio of 12O2 and 13CO2 concentrations in the human exhaled air is measured by the method of diode laser spectroscopy using a three-channel optical scheme and multipass cell. Unlike the previous measurements in the spectral range of ~4.3 ?m with a resolved rotational structure at low pressure of selected samples, the present measurements are performed in the range of ~2 ?m, in which weaker absorption bands of CO2 reside. In this case, it is possible to employ lasers and photodetectors operating at room temperature. The thorough simulation of the spectrum with collisional broadening of lines and employment of regression analysis allow one to take measurements at atmospheric pressure with the accuracy of ~0.04%, which satisfies the requirements to medical diagnostics of ulcers.

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

2009-04-01

245

Carbon dioxide transport in crustal magmatic systems  

NASA Astrophysics Data System (ADS)

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

Yoshimura, Shumpei; Nakamura, Michihiko

2011-07-01

246

Carbon Dioxide: Production and Sequestration  

NSDL National Science Digital Library

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.

247

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

E-print Network

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

Kaiser, Ralf I.

248

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

E-print Network

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

Wu, Jianzhong

249

Climate impact of increasing atmospheric carbon dioxide  

SciTech Connect

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

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

1981-08-28

250

Heterogeneous catalytic reactions of carbon dioxide  

NASA Astrophysics Data System (ADS)

The most important classes of heterogeneous catalytic reactions involving CO2 are examined: the incorporation of CO2 in the C-C, C-H, and C-N bonds with formation of carbonyl- and carboxyl-containing compounds and oxidation of other compounds by CO2. Reactions of the second class are more promising from the standpoint of the utilisation of carbon dioxide as a chemical raw material and from the standpoint of the solution of the ecological problems involving its utilisation from the gaseous waste discharged into the atmosphere. The reactions involving the oxidation of C1-C7 hydrocarbons and C1-C2 alcohols by carbon dioxide, which have been investigated by the authors of this review, are examined in detail. Catalysts based on manganese oxides are most effective in these reactions. The bibliography includes 231 references.

Krylov, Oleg V.; Mamedov, A. Kh

1995-09-01

251

Plasma Dynamics in Double-Pulse LIBS on Dicarboxylic Acids Using Combined 532 nm Nd:YAG and Carbon Dioxide Laser Pulses.  

PubMed

Laser-induced breakdown spectroscopy (LIBS) was used as a method to monitor the evolution of C, hydrogen-?, carbon-carbon, and carbon-nitrogen spectral emissions from atmospheric recombination in a specific set of organic materials. Ablated samples were composed of a series of linear chain dicarboxylic acids with two to seven C atoms. Accumulated pulses of a focused neodymium-doped yttrium aluminum garnet (Nd:YAG) Q-switched laser beam operated at 532 nm generate a plasma in air at the sample surface. In this work, a dual-pulse LIBS technique was used to improve signal strength by enhancing the nanosecond LIBS plasma with CO2 transverse-excited breakdown in atmosphere laser pulses with an operating wavelength of 10.6 ?m. Through a time-resolved analysis, we demonstrate the correlation between the signal strength of selected emissions and the number of C atoms in the linear chain. We also illustrate the effects that these constraints, along with the presence of a chiral C in the chain, have on the peak intensities of the individual lines with respect to each other by comparing the increase or nonexistence of certain spectral lines as we increase the number of C atoms in the linear chain. PMID:25226259

Brown, Staci R; Akpovo, Charlemagne A; Martinez, Jorge; Johnson, Lewis

2014-09-01

252

The direct carbon dioxide effect on plants  

Microsoft Academic Search

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

Jonathan Adams

253

Carbon dioxide separation from hydrogen and nitrogen  

Microsoft Academic Search

CO2-selective membranes that obtain high CO2 permeabilities accompanied with high CO2\\/H2 and CO2\\/N2 separation factors at industrial temperatures and pressures are applicable to fuel cell operations and flue gas purification. This paper describes the separation of carbon dioxide from a mixed gas stream of hydrogen and nitrogen by a chitosan membrane containing 40wt% sodium arginate. Continuous membrane separations were done

Louei A. El-Azzami; Eric A. Grulke

2009-01-01

254

Carbon dioxide balneotherapy and cardiovascular disease  

Microsoft Academic Search

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

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

255

Carbon dioxide sequestration: how much and when?  

Microsoft Academic Search

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

Klaus Keller; David McInerney; David F. Bradford

2008-01-01

256

Electrochemical carbon dioxide concentrator: Math model  

NASA Technical Reports Server (NTRS)

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

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

1973-01-01

257

Transport of Carbon Dioxide and Radioactive Waste  

Microsoft Academic Search

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

Daro R. Gmez; Michael Tyacke

258

Elevated atmospheric carbon dioxide increases soil carbon  

SciTech Connect

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

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

2005-01-01

259

Carbon dioxide in Arctic and subarctic regions  

SciTech Connect

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

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

1981-03-01

260

Carbon dioxide sensitivity of zeolitic imidazolate frameworks.  

PubMed

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

Mottillo, Cristina; Fri?i?, Tomislav

2014-07-14

261

Carbon dioxide disposal in carbonate minerals  

Microsoft Academic Search

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

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

1995-01-01

262

Carbon dioxide solubility and carbon isotope fractionation in basaltic melt  

SciTech Connect

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%.

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

1991-11-01

263

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

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

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

2001-07-01

264

Carbon Dioxide Separation Using Thermally Optimized Membranes  

NASA Astrophysics Data System (ADS)

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

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

2002-05-01

265

Robust carbon dioxide reduction on molybdenum disulphide edges.  

PubMed

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

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

2014-01-01

266

Enriching blast furnace gas by removing carbon dioxide.  

PubMed

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

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

2013-12-01

267

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

ERIC Educational Resources Information Center

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

Brewer, Carol A.; Beiswenger, Jane M.

1993-01-01

268

Thermal Infrared Radiation and Carbon Dioxide in the Atmosphere  

E-print Network

interaction with infrared · Basic model and some results #12;#12;#12;Earth's emitted spectrum Ozone Carbon #12;Fine structure of carbon dioxide absorption spectrum near 15 micron wavelength #12Thermal Infrared Radiation and Carbon Dioxide in the Atmosphere Bill Satzer 3M Company #12;Outline

Olver, Peter

269

Carbon Dioxide Production in the Oxidation of Organic  

E-print Network

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

Steinbock, Oliver

270

Thermochemical generation of hydrogen and carbon dioxide  

NASA Technical Reports Server (NTRS)

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

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

1984-01-01

271

Optical Sensors for Carbon Dioxide and Their Applications  

Microsoft Academic Search

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

Andrew Mills

272

Carbon dioxide resistance of fiberglass oil field pipe  

SciTech Connect

Unlined aromatic amine-cured epoxy fiberglass piping systems have been successfully used to handle oil field services requiring resistance to carbon dioxide. Fiberglass pipe made from vinyl ester and premium isophthalic polyester resins have also been proposed for use in this type of service. This paper presents test data comparing the carbon dioxide resistance of fiberglass pipe made from these three resins. Test data for fiberglass pipe exposed to carbon dioxide containing 5% hydrogen sulfide are also presented.

Oswald, K.J.

1988-08-01

273

Supercritical carbon dioxide: a solvent like no other  

PubMed Central

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

Peach, Jocelyn

2014-01-01

274

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

PubMed

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

Carlson, R W

1999-02-01

275

Toward solar fuels: photocatalytic conversion of carbon dioxide to hydrocarbons.  

PubMed

The past several decades have seen a significant rise in atmospheric carbon dioxide levels resulting from the combustion of hydrocarbon fuels. A solar energy based technology to recycle carbon dioxide into readily transportable hydrocarbon fuel (i.e., a solar fuel) would help reduce atmospheric CO2 levels and partly fulfill energy demands within the present hydrocarbon based fuel infrastructure. We review the present status of carbon dioxide conversion techniques, with particular attention to a recently developed photocatalytic process to convert carbon dioxide and water vapor into hydrocarbon fuels using sunlight. PMID:20141175

Roy, Somnath C; Varghese, Oomman K; Paulose, Maggie; Grimes, Craig A

2010-03-23

276

Production of precipitated calcium carbonate from calcium silicates and carbon dioxide  

Microsoft Academic Search

The possibilities for reducing carbon dioxide emissions from the pulp and paper industry by calcium carbonation are presented. The current precipitated calcium carbonate (PCC) production uses mined, crushed calcium carbonate as raw materials. If calcium silicates were used instead, carbon dioxide emissions from the calcination of carbonates would be eliminated. In Finland, there could, thus, be a potential for eliminating

Sebastian Teir; Sanni Eloneva; Ron Zevenhoven

2005-01-01

277

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

E-print Network

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

Barthelat, Francois

278

A photoelectrochemical approach to splitting carbon dioxide for a manned mission to Mars  

Microsoft Academic Search

A photoelectrochemical system for splitting carbon dioxide to carbon monoxide and oxygen is discussed. The Martian atmosphere consists of 95% carbon dioxide. Splitting carbon dioxide would provide both oxygen to support life and carbon monoxide, which can be used as a substitute for hydrogen fuel. The photoelectrochemical system involves a cathodic compartment where reduction of carbon dioxide to carbon monoxide

Brian K Breedlove; Gregory M Ferrence; John Washington; Clifford P Kubiak

2001-01-01

279

Searching for clues to ancient carbon dioxide  

SciTech Connect

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

Appenzeller, T.

1993-02-12

280

Absorption of Carbon Dioxide in Aqueous Piperazine/Methyldiethanolamine  

E-print Network

Absorption of Carbon Dioxide in Aqueous Piperazine/Methyldiethanolamine Sanjay Bishnoi and Gary T dioxide absorption in 0.6 M piperazine PZ r4 M methyldiethanolamine ( )MDEA was measured in a wetted wall dioxide from synthesis gas in ammonia plants and hydrogenrcarbon Z .monoxide plants Wammes et al., 1994

Rochelle, Gary T.

281

Photoacoustic spectrometer for accurate, continuous measurements of atmospheric carbon dioxide concentration  

NASA Astrophysics Data System (ADS)

We have developed a portable photoacoustic spectrometer that offers routine, precise and accurate measurements of the molar concentration of atmospheric carbon. The temperature-controlled spectrometer continuously samples dried atmospheric air and employs an intensity-modulated distributed feedback laser and fiber amplifier operating near 1.57 m. For measurements of carbon dioxide in air, we demonstrate a measurement precision (60-s averaging time) of 0.15 mol mol-1 and achieve a standard uncertainty of 0.8 mol mol-1 by calibrating the analyzer response in terms of certified gas mixtures. We also investigate how water vapor affects the photoacoustic signal by promoting collisional relaxation of the carbon dioxide.

Reed, Zachary D.; Sperling, Brent; van Zee, Roger D.; Whetstone, James R.; Gillis, Keith A.; Hodges, Joseph T.

2014-06-01

282

The lifetime of excess atmospheric carbon dioxide  

SciTech Connect

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

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

1994-03-01

283

Carbon dioxide research plan. A summary  

SciTech Connect

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

Not Available

1983-11-01

284

Modeling flow of mineralized carbon dioxide slurry  

SciTech Connect

Direct mineral carbonation was investigated at Albany Research Center (US DOE) as a means to sequester carbon dioxide into stable mineral matrices. Although previous work focused on treating Mg-containing minerals in conventional autoclaves, recent work has been done using pipeline-reactor technology for the high-temperature, high-pressure (HTHP) reaction of the minerals in aqueous/CO2 media. Sequestration of CO2 using above-ground reactors may be uneconomical, but the technology may also be applicable in geological sequestration of CO2. Progress is described in using a prototype HTHP flow-loop reactor to model flow in the dynamic three-phase system to help determine the pumping-energy requirements to optimize reactivity.

Penner, Larry R.; Dahlin, David C.; Gerdemann, Stephen J.; Saha, K.K. (Mechanical and Aerospace Engineering Dept., Computational Fluid Dynamics Laboratory, Arizona State University)

2005-04-01

285

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.

286

Titrimetric Determination of Carbon Dioxide in a Heterogeneous Sample  

Microsoft Academic Search

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

Craig M. Davis; Matthew C. Mauck

2003-01-01

287

Carbon Dioxide Fluxes in European Russia  

NASA Astrophysics Data System (ADS)

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

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

2007-12-01

288

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

Code of Federal Regulations, 2010 CFR

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

2010-04-01

289

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

Federal Register 2010, 2011, 2012, 2013

...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 )...

2011-09-09

290

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

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

2014-10-01

291

Modeling Infinite Dilution and Fickian Diffusion Coefficients of Carbon Dioxide in Water  

E-print Network

Modeling Infinite Dilution and Fickian Diffusion Coefficients of Carbon Dioxide in Water J. Wambui infinite dilution diffusion coefficients for carbon dioxide and water mixtures. The model takes, carbon dioxide, classical thermodynamics Introduction The increase in atmospheric concentrations of CO2

Firoozabadi, Abbas

292

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

E-print Network

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

Santiago, Juan G.

293

49 CFR 175.900 - Handling requirements for carbon dioxide, solid (dry ice).  

...2014-10-01 false Handling requirements for carbon dioxide, solid (dry ice). 175.900 Section...175.900 Handling requirements for carbon dioxide, solid (dry ice). Carbon dioxide, solid (dry ice) when shipped...

2014-10-01

294

Hydrodynamic Controls on Carbon Dioxide Efflux from Inland Waters  

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

295

CARBON DIOXIDE STANDARD EMISSIVITY BY MIXED GRAY-GASES MODEL  

Microsoft Academic Search

Conventional fossil fuels are of carbon-hydrogen composition. A number of alternative fuels, e.g., coal, lignite, are carbon-based fuels. The high temperature combustion of such fuels would generate carbon dioxide, and if hydrogen is present, water vapor. The knowledge of the emissivities of carbon dioxide and water vapor is very important in burner design and thermal efficiency calculations. The present work

IHAB H. FARAG; T. A. ALLAM

1982-01-01

296

Saving energy and optimizing air quality using carbon dioxide (CO)  

Microsoft Academic Search

Demand control ventilation (DCV) using carbon dioxide offers a unique opportunity for building designers and owners to resolve an age-old paradox: how to reduce energy costs while optimizing air quality. Recent innovations in gas sensor designs have considerably improved the long-term performance and cost of carbon dioxide sensing, making it one of the fastest growing segments of the HVAC control

Schell

1998-01-01

297

Carbon dioxide emission during forest fires ignited by lightning  

E-print Network

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

Pelc, Magdalena

2009-01-01

298

Carbon Dioxide Capture DOI: 10.1002/anie.201000431  

E-print Network

gas and phasing in the use of renewable energy resources (e.g., solar energy, wind, and biomassCarbon Dioxide Capture DOI: 10.1002/anie.201000431 Carbon Dioxide Capture: Prospects for New The prospect of a worsening climatic situation due to global warming is a subject of widespread public concern

299

Method and apparatus for producing food grade carbon dioxide  

Microsoft Academic Search

A method is disclosed of producing food grade carbon dioxide from an impure carbon dioxide source stream containing contaminants which may include light and heavy hydrocarbons (at least C to C) and light sulfur compounds such as hydrogen sulfide and carbonyl sulfide as well as heavier sulfur constituents in the nature of mercaptans (RSH) and\\/or organic mono and disulfides (RSR

J. E. Nobles; L. K. Swenson

1984-01-01

300

27 CFR 26.52 - Still wines containing carbon dioxide.  

Code of Federal Regulations, 2010 CFR

...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...

2010-04-01

301

27 CFR 26.222 - Still wines containing carbon dioxide.  

Code of Federal Regulations, 2010 CFR

...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...

2010-04-01

302

Recovery of carbon dioxide from fuel cell exhaust  

Microsoft Academic Search

An acid fuel cell power plant system operable to produce carbon dioxide as a by-product is described comprising: (a) fuel cell stack means having anode means, cathode means, and fuel cell cooling means, the cooling means using a water coolant; (b) means for delivering a hydrogen-rich fuel gas which contains carbon dioxide to the anode means for consumption of hydrogen

H. C. Healy; M. Kolodney; A. H. Levy; P. Trocciola

1988-01-01

303

Carbon Dioxide Reforming of Methane to Syngas by Thermal Plasma  

Microsoft Academic Search

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

Sun Yanpeng; Nie Yong; Wu Angshan; Ji Dengxiang; Yu Fengwen; Ji Jianbing

2012-01-01

304

Options for the collection and disposal of carbon dioxide  

Microsoft Academic Search

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

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

1980-01-01

305

Response of the oceans to increasing atmospheric carbon dioxide  

Microsoft Academic Search

The rate at which the oceans take up excess atmospheric carbon dioxide from the burning of fossil fuels is an important factor in determining the rate of increase in the atmospheric concentration of carbon dioxide and the maximum value it will reach. In this review are considered the relevant physical and chemical features of the ocean, the observational evidence of

Baes; C. F. Jr

1981-01-01

306

Measurements of atmospheric carbon dioxide concentration above the ocean  

Microsoft Academic Search

Changes in the composition of the atmosphere can have a destabilizing effect on the climate. One change is related to an increase in the concentration of carbon dioxide as a result of the combustion of organic fuels. The most effective procedures for monitoring the atmospheric carbon dioxide concentration are discussed, taking into account suitable analytic methods and the most appropriate

A. I. Voskresenskii; N. E. Kamenogradskii; V. P. Ustinov

1984-01-01

307

Isothermal and isobaric desorption of carbon dioxide by purge  

Microsoft Academic Search

Adsorption and desorption constitute the two most basic steps in all pressure swing adsorption (PSA) processes for gas separation. The desorption steps are the primary energy-consuming steps in the PSA process. They also dictate the overall separation efficiency. Isothermal and isobaric desorption of carbon dioxide was experimentally evaluated by purging adsorbent columns saturated with pure carbon dioxide with pure hydrogen,

Shivaji Sircar; Timothy C. Golden

1995-01-01

308

Performance of air filters cleaned by supercritical carbon dioxide  

Microsoft Academic Search

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

Takao Ito; Yoshio Otani; Hiroshi Inomata

2004-01-01

309

The Greenness of Cities: Carbon Dioxide Emissions and Urban Development  

Microsoft Academic Search

Carbon dioxide emissions may create significant social harm because of global warming, yet American urban development tends to be in low density areas with very hot summers. In this paper, we attempt to quantify the carbon dioxide emissions associated with new construction in different locations across the country. We look at emissions from driving, public transit, home heating, and household

Edward L. Glaeser; Matthew E. Kahn

2008-01-01

310

The greenness of cities: Carbon dioxide emissions and urban development  

Microsoft Academic Search

Carbon dioxide emissions may create significant social harm because of global warming, yet American urban development tends to be in low density areas with very hot summers. In this paper, we attempt to quantify the carbon dioxide emissions associated with new construction in different locations across the country. We look at emissions from driving, public transit, home heating, and household

Edward L. Glaeser; Matthew E. Kahn

2010-01-01

311

Criteria for Intermediate Storage of Carbon Dioxide in Geological Formations  

Microsoft Academic Search

The greenhouse gas (GHG) making the largest contribution to atmospheric emissions from human activities is carbon dioxide (CO 2) and released dominantly by burning fossil fuels such as coal, oil, and natural gas. Increased emissions of GHG, causes global warming thus steps should be taken that aim in the stabilization of greenhouse gas concentrations in the atmosphere. Carbon dioxide capture

Semere Solomon

312

Uptake of carbon dioxide from flue gas by microalgae  

Microsoft Academic Search

The technology under development seeks to provide affordable, and efficient methods for reducing carbon dioxide and other emissions from coal-fired electricity generation based on biological assimilation. Photosynthetic microorganisms such as microalgae, when grown in large outdoor ponds could use carbon dioxide from flue gas directly injected into the culture. This process requires land, water, sunlight and other nutrients. Currently, commercial

Lewis M. Brown

1996-01-01

313

Investigating Diffusion and Entropy with Carbon Dioxide-Filled Balloons  

ERIC Educational Resources Information Center

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

Jadrich, James; Bruxvoort, Crystal

2010-01-01

314

Investigating Diffusion and Entropy with Carbon Dioxide-Filled Balloons  

Microsoft Academic Search

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

James Jadrich; Crystal Bruxvoort

2010-01-01

315

Process Based Belowground Carbon Dioxide Modeling in a Desert Ecosystem  

Microsoft Academic Search

We describe a study to integrate and assess biological and physical processes that govern belowground carbon dioxide levels at a semi-arid grassland near Canyonlands National Park. Carbon dioxide concentrations were measured every 30 minutes at 5 and 15 cm depth within the rooting zones of the two dominant grass species, Stipa hymenoides and Hilaria jamesii, as well as the interspace

J. M. Zobitz; D. R. Bowling

2003-01-01

316

Carbon dioxide sequestration in concrete in different curing environments  

E-print Network

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

Wisconsin-Milwaukee, University of

317

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

NSDL National Science Digital Library

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

Nutshell, Planet; Network, Utah E.

318

Carbon dioxide emission during forest fires ignited by lightning  

E-print Network

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

Magdalena Pelc; Radoslaw Osuch

2009-03-31

319

Carbon Dioxide Sequestration Capacity of the Mt Simon Formation  

NASA Astrophysics Data System (ADS)

A technique has been developed to better predict the quantity of carbon dioxide that can be sequestered in a formation through solubility or free phase trapping. The technique is being improved to incorporate the potential for carbonate mineral precipitation. The current study evaluates the extent to which the Mt. Simon formation can serve as a trapping reservoir. The Mt. Simon formation was selected for this study because it meets many of the criteria required for sequestration. To determine the capacity of the Mt. Simon formation to trap carbon dioxide as a soluble component, an experiment was conducted in natural Mt. Simon formation brine. The experiment was conducted at 55 degrees Celsius and pressures from 50 to 350 bars, conditions that fall within the range expected for the entire formation. The data collected compare well to existing models that only account for carbon dioxide solubility. Thus, the solubility model can be reliably used to predict dissolved carbon dioxide concentrations for the range of temperatures and pressures expected to be encountered. The capacity of the Mt. Simon formation to sequester dissolved carbon dioxide was calculated using results of the solubility model, estimation of the density of carbon dioxide saturated brine, estimation of the formation porosity, and geographic information system data on the extent of the formation. Results indicate that the Mt. Simon formation can sequester as much as 26 Gt of dissolved carbon dioxide or 255 Gt of free phase carbon dioxide depending on the efficiency of the system. The current estimated annual production of carbon dioxide from power plant emissions of IL, IA and MI is 0.24 Gt. This indicates that the basin could accept the annual emissions of these power plants for approximately 100 years or more if current carbon dioxide production does not increase.

Allen, D. E.; Dilmore, B.; Hedges, S.; Soong, Y.

2008-12-01

320

Carbon dioxide absorbent and method of using the same  

DOEpatents

In accordance with one aspect, the present invention provides an amino-siloxane composition comprising at least one of structures I, II, III, IV or V said compositions being useful for the capture of carbon dioxide from gas streams such as power plant flue gases. In addition, the present invention provides methods of preparing the amino-siloxane compositions are provided. Also provided are methods for reducing the amount of carbon dioxide in a process stream employing the amino-siloxane compositions of the invention as species which react with carbon dioxide to form an adduct with carbon dioxide. The reaction of the amino-siloxane compositions provided by the present invention with carbon dioxide is reversible and thus, the method provides for multicycle use of said compositions.

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

2011-10-04

321

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

Microsoft Academic Search

Carbon dioxide (CO) dioxide (CO) mixing ratio and isotopic carbon-13 dioxide δ¹³CO 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 changes during periods of different climatic conditions and to gain insight into the mechanisms

Wahlen

1994-01-01

322

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

Microsoft Academic Search

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

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

2011-01-01

323

Dissociation-excitation reactions of argon metastables with carbon dioxide.  

NASA Technical Reports Server (NTRS)

Results of a study showing that a metastable argon-carbon dioxide reaction results in dissociation of carbon dioxide and electronic excitation of one of the products, carbon monoxide or oxygen. A flow system using a 2450-MHz discharge was used to produce metastable argon atoms. Metastable argon in the afterglow was confirmed by adding nitrogen to the afterglow. Without addition of carbon dioxide no argon line emission, or any other emission, is observed from the reaction zone. Absence of argon line emission produced by recombination indicates the absence of charged species.

Starr, W. L.

1971-01-01

324

Miniaturized remission sensor for carbon dioxide detection  

NASA Astrophysics Data System (ADS)

Recently, optical sensors for detection of carbon dioxide (CO2) have been explored for variety of applications in chemistry, industry, and medicine. This paper deals with the development of a planar optical remission sensor employing a dye immobilized in a polymer layer designed for gaseous CO2 detection. The principle of CO2 detection was based on colour changes of Tetraethylammonium Cresol red immobilized in a special composed polymer layer that was irradiated by LED diodes. Absorption properties of the dye were changed due to its chemical reaction with CO2 and corresponding colour changes were detected by PIN diodes. These changes were analyzed by using a PC-controlled board connected by USB. The sensitivity, response time, and the detection limit of the remission sensor were characterized.

Martan, T.; Will, M.

2010-02-01

325

Calcium Oxide Matrices and Carbon Dioxide Sensors  

PubMed Central

Homogeneous matrices of calcium oxide (CaO) were prepared by mixing this material with polyethylene glycol (PEG) acting as malleable inert support in order to obtain processable composites. Preliminary tests were carried out to assess the best concentration of CaO in the composite, individuated in the CaO/PEG weight ratio of 1/4. Experimental data highlighted that the composite was able to selectively detect carbon dioxide (CO2) via a nanogravimetric method by performing the experiments inside an atmosphere-controlled chamber filled with CO2. Furthermore, the composite material showed a linear absorption of CO2 as a function of the gas concentration inside the atmosphere-controlled chamber, thus paving the way for the possible use of these matrices for applications in the field of sensor devices for long-term evaluation of accumulated environmental CO2. PMID:22778620

Terencio, Tercio Bezerra Correia; Bavastrello, Valter; Nicolini, Claudio

2012-01-01

326

Demographic change and carbon dioxide emissions.  

PubMed

Relations between demographic change and emissions of the major greenhouse gas carbon dioxide (CO(2)) have been studied from different perspectives, but most projections of future emissions only partly take demographic influences into account. We review two types of evidence for how CO(2) emissions from the use of fossil fuels are affected by demographic factors such as population growth or decline, ageing, urbanisation, and changes in household size. First, empirical analyses of historical trends tend to show that CO(2) emissions from energy use respond almost proportionately to changes in population size and that ageing and urbanisation have less than proportional but statistically significant effects. Second, scenario analyses show that alternative population growth paths could have substantial effects on global emissions of CO(2) several decades from now, and that ageing and urbanisation can have important effects in particular world regions. These results imply that policies that slow population growth would probably also have climate-related benefits. PMID:22784534

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

2012-07-14

327

The Fluid Mechanics of Carbon Dioxide Sequestration  

NASA Astrophysics Data System (ADS)

Humans are faced with a potentially disastrous global problem owing to the current emission of 32 gigatonnes of carbon dioxide (CO2) annually into the atmosphere. A possible way to mitigate the effects is to store CO2 in large porous reservoirs within the Earth. Fluid mechanics plays a key role in determining both the feasibility and risks involved in this geological sequestration. We review current research efforts looking at the propagation of CO2 within the subsurface, the possible rates of leakage, the mechanisms that act to stably trap CO2, and the geomechanical response of the crust to large-scale CO2 injection. We conclude with an outline for future research.

Huppert, Herbert E.; Neufeld, Jerome A.

2014-01-01

328

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

Microsoft Academic Search

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

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

2002-01-01

329

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

Microsoft Academic Search

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

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

2002-01-01

330

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

SciTech Connect

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.

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

331

Does carbon dioxide pool or stream in the subsurface?  

E-print Network

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

Cardoso, Silvana S S

2014-01-01

332

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

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

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

2005-01-01

333

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

SciTech Connect

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.

Neta, P.

2002-09-01

334

Estimated Carbon Dioxide Emissions in 2008: United States  

SciTech Connect

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

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

2011-04-01

335

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

NASA Astrophysics Data System (ADS)

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

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

2007-12-01

336

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

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

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

2005-07-01

337

Carbon dioxide warming of the early Earth  

NASA Technical Reports Server (NTRS)

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

Arrhenius, G.

1997-01-01

338

Carbon dioxide warming of the early Earth.  

PubMed

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

Arrhenius, G

1997-02-01

339

Can the carbon dioxide problem be resolved  

SciTech Connect

The combustion of fossil fuels increases atmospheric levels of carbon dioxide (CO/sub 2/). This may cause a long-term warming of the atmosphere. Solutions to the CO/sub 2/ problem are particularly difficult because adverse effects will be felt by future generations, but remedial action and sacrifices must be made by present generations. Decisions regarding the problem which affect both the immediate and long-range future must be made deliberately or by default in perhaps only 15 to 20 years, before we are reasonably confident of our knowledge of the problem and before we know whether atmospheric warming will, in fact, occur. Empirical and evaluative data do not seem compelling to decision makers. First, remedial actions require present generations to conserve fossil fuels for the benefit of posterity, and there is no consensus that an ethical obligation to posterity exists. Second, actions must be based upon uncertain projections of future energy use and uncertain scientific knowledge of the carbon cycle and the environment. Third, economic and social factors may preclude resolution of the problem. Fourth, speculation from moral psychology suggests that mankind may be psychologically incapable of caring enough for posterity to make serious sacrifices. Therefore, public policy regarding sacrifice by present generations for the benefit of posterity is not likely to be forthcoming from policy makers or suported by the public. 120 references.

Lemons, J.

1984-01-01

340

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

SciTech Connect

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

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

1994-12-31

341

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

E-print Network

of carbon dioxide by the burning of fossil fuels ( 6 billion tons of carbon per year). Possible shiftsModel-based estimation of the global carbon budget and its uncertainty from carbon dioxide, balancing emissions from fossil fuel and land use with carbon uptake by the oceans, and the terrestrial

Jain, Atul K.

342

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

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

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

2005-04-01

343

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

ERIC Educational Resources Information Center

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

Alcamo, Joseph; De Vries, Bert

1992-01-01

344

Separation of Carbon Monoxide and Carbon Dioxide for Mars ISRU  

NASA Technical Reports Server (NTRS)

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

Walton, Krista S.; LeVan, M. Douglas

2004-01-01

345

Membranes for separation of carbon dioxide  

DOEpatents

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

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

2011-03-01

346

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

Microsoft Academic Search

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

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

1995-01-01

347

2008 Nature Publishing Group Atmospheric carbon dioxide linked  

E-print Network

atmosphere reaching back over 200 Myr, by using a new method based on the strong dependency of carbon-isotope concentrations from a combination of carbon-isotope analyses of non-vascular plant (bryophyte) fossils© 2008 Nature Publishing Group LETTERS Atmospheric carbon dioxide linked with Mesozoic and early

Cai, Long

348

Pretreatment for cellulose hydrolysis by carbon dioxide explosion  

SciTech Connect

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.

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

349

Synthesis of Amides and Lactams in Supercritical Carbon Dioxide  

E-print Network

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

Mak, Xiao Yin

350

Control strategies for supercritical carbon dioxide power conversion systems  

E-print Network

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

Carstens, Nathan, 1978-

2007-01-01

351

Mechanism of oxidative carbon dioxide production during Renilla reniformis bioluminescence.  

PubMed

The oxidation of luciferin catalyzed by sea pansy luciferase results in the emission of light. Molecular oxygen is required and carbon dioxide is produced. When the reaction occurs in the presence of H(2) (18)O, both of the oxygens of the carbon dioxide are labeled. One of the oxygens arises from the nonenzymic exchange of the ketone group of the substrate; the other oxygen is incorporated during the enzymic oxidation of the luciferin. When the reaction is carried out in the presence of (18)O(2), neither of the oxygens of the carbon dioxide is labeled. Thus the source of oxygen in the carbon dioxide is water. A mechanism for the oxidative reaction is proposed. PMID:4397765

DeLuca, M; Dempsey, M E; Hori, K; Wampler, J E; Cormier, M J

1971-07-01

352

Electrochemically-mediated amine regeneration for carbon dioxide separations  

E-print Network

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

Stern, Michael C. (Michael Craig)

2014-01-01

353

World energy consumption and carbon dioxide emissions : 1950-2050  

E-print Network

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

Schmalensee, Richard

1995-01-01

354

World energy consumption and carbon dioxide emissions : 1950-2050  

E-print Network

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

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

355

Atmospheric concentrations of carbon dioxide, methane and nitrous oxide  

NSDL National Science Digital Library

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

IPCC (Intergovernmental Panel of Climate Change)

356

Role of Carbon Dioxide in Inert Gas Narcosis.  

National Technical Information Service (NTIS)

The role of carbon dioxide and oxygen in high pressure narcosis was studied by exposing animals to hyperbaric conditions while maintaining them normoxic and normocapnic. Chickens were the experimental animals. Heated, humidified gas entered the lung via a...

H. S. Weiss

1977-01-01

357

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

NASA Technical Reports Server (NTRS)

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

Johnson, F. S.

1975-01-01

358

Permanent storage of carbon dioxide in geological reservoirs by mineral carbonation  

Microsoft Academic Search

Anthropogenic greenhouse-gas emissions continue to increase rapidly despite efforts aimed at curbing the release of such gases. One potentially long-term solution for offsetting these emissions is the capture and storage of carbon dioxide. In principle, fluid or gaseous carbon dioxide can be injected into the Earth's crust and locked up as carbonate minerals through chemical reactions with calcium and magnesium

Peter B. Kelemen; Jrg M. Matter

2009-01-01

359

Testing a Regenerative Carbon Dioxide and Moisture Removal Technology  

Microsoft Academic Search

The National Aeronautics and Space Administration supported the development of a new vacuum-desorbed regenerative carbon dioxide and humidity control technology for use in short duration human spacecraft. The technology was baselined for use in the Orion Crew Exploration Vehicle's Environmental Control and Life Support System (ECLSS). Termed the Carbon Diox-ide And Moisture Removal Amine Swing-bed (CAMRAS), the unit was developed

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

2010-01-01

360

Measurements of Surface Ocean Carbon Dioxide Partial Pressure During WOCE  

Microsoft Academic Search

All of the technical goals of the World Ocean Circulation Experiment (WOCE) field program which were supported under the Department of Energy research grant ''Measurements of Surface Ocean Carbon Dioxide Partial Pressure During WOCE'' (DE-FG03-90ER60981) have been met. This has included the measurement of the partial pressures of carbon dioxide (C0) and nitrous oxide (NO) in both the surface ocean

1998-01-01

361

Carbon dioxide in the ocean surface: The homogeneous buffer factor  

USGS Publications Warehouse

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

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

1979-01-01

362

Seawater pH and Anthropogenic Carbon Dioxide  

E-print Network

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.

Gerald E. Marsh

2008-10-20

363

Suppressing bullfrog larvae with carbon dioxide  

USGS Publications Warehouse

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

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

2014-01-01

364

Carbon dioxide balneotherapy and cardiovascular disease  

NASA Astrophysics Data System (ADS)

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

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

2011-09-01

365

Synthetic fuels, carbon dioxide and climate  

NASA Astrophysics Data System (ADS)

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 used instead of petroleum. The use of synthetic fuels derivved from biomass would make no net addition to atmospheric CO2 provided no fossil fuels are used in biomass production and/or conversion. Assuming that synthetic liquid fuels would gradually replace petroleum and that they would supply all of the worldwide liquid fuel demand by the year 2060, we calculated that the atmospheric CO2 concentration would increase from the current 335 parts per million on a volume basis (ppmv) to 778 ppmv in 2060. However, even if the liquid fuel demand were met by petroleum alone, the CO2 level would be 715 ppmv in that year. Furthermore, we estimated that as a result of these increases in the CO2 level, the globally averaged earth's surface temperature in the year 2060 will have risen by 2.6 K with the use of synthetic liquids and 2.2 K without their use.

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

1982-05-01

366

Euthanasia of neonatal mice with carbon dioxide  

USGS Publications Warehouse

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

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

2005-01-01

367

Carbon dioxide dynamics in an artificial ecosystem  

NASA Astrophysics Data System (ADS)

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

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

368

Low-temperature data for carbon dioxide  

E-print Network

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 ...

Azreg-Anou, Mustapha

2014-01-01

369

Carbon nanoparticles from laser pyrolysis  

Microsoft Academic Search

Carbon nanoparticles synthesised by laser pyrolysis of hydrocarbons in a flow reactor have been investigated as a function of laser power. Samples are cross-characterised by high resolution transmission electron microscopy (HRTEM) and infrared (IR) spectroscopy. Nanoparticles appear highly aromatic in character in all the experimental conditions explored here. As the flame temperature in the interaction zone increases, the nanoparticles evolve

Aymeric Galvez; Nathalie Herlin-Boime; Ccile Reynaud; Christian Clinard; Jean-Nol Rouzaud

2002-01-01

370

Renewable and metal-free carbon nanofibre catalysts for carbon dioxide reduction  

NASA Astrophysics Data System (ADS)

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.

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

371

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

Microsoft Academic Search

A 400 record of atmospheric carbon dioxide levels has been estimated by applying a 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

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

1999-01-01

372

Carbon Dioxide Reduction Technology Trade Study  

NASA Technical Reports Server (NTRS)

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

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

2011-01-01

373

14 April 2001 tmospheric carbon dioxide  

E-print Network

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

Teskey, Robert O.

374

Ionic Liquid Membranes for Carbon Dioxide Separation  

SciTech Connect

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

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

2008-07-12

375

Carbon dioxide exchange in a peatland ecosystem  

NASA Astrophysics Data System (ADS)

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

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

1995-07-01

376

Interfacial tension measurements and modelling of (carbon dioxide + n-alkane) and (carbon dioxide + water) binary mixtures at elevated pressures and temperatures  

Microsoft Academic Search

Supercritical carbon dioxide (CO2) is often used as a process fluid for enhanced oil recovery. The storage of carbon dioxide in underground formations is a potential way of mitigating climate change during a transition period to more sustainable energy sources. Combining injection with subsequent trapping of the non-wetting supercritical carbon dioxide phase in the pores of a depleted reservoir is

Apostolos Georgiadis; Felix Llovell; Alexander Bismarck; Felipe J. Blas; Amparo Galindo; Geoffrey C. Maitland; J. P. Martin Trusler; George Jackson

2010-01-01

377

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

E-print Network

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

378

Persistent local order heterogeneity in the supercritical carbon dioxide  

E-print Network

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

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

2014-06-06

379

Study of redox reactions to split water and carbon dioxide  

NASA Astrophysics Data System (ADS)

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

Arifin, Darwin

380

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

SciTech Connect

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

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

1980-04-01

381

A role for nickel-iron cofactors in biological carbon monoxide and carbon dioxide utilization  

E-print Network

NiFe containing enzymes are involved in the biological utilization of carbon monoxide, carbon dioxide, and hydrogen. Interest in these enzymes has increased in recent years due to hydrogen fuel initiatives and concerns ...

Kung, Yan

382

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

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

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

2002-10-01

383

Enhanced carbon dioxide uptake by the world's oceans  

Microsoft Academic Search

The growth of phytoplankton over much of the ocean is limited by the availability of nitrogen in the upper sunlit region of the ocean. It is through photosynthesis that upper ocean carbon is exported to the deep ocean and replaced with carbon dioxide fluxed by physical processes from the atmosphere. The addition of nitrogen to the ocean surface waters has

Ian S. F. Jones

1996-01-01

384

Carbon dioxide separation from high temperature fuel cell power plants  

Microsoft Academic Search

High temperature fuel cell technologies, solid oxide fuel cells (SOFCs) and molten carbonate fuel cells (MCFCs), are considered for their potential application to carbon dioxide emission control. Both technologies feature electrochemical oxidisation of natural gas reformed fuels, avoiding the mixture of air and fuel flows and dilution with nitrogen and oxygen of the oxidised products; a preliminary analysis shows how

Stefano Campanari

2002-01-01

385

Mechanisms of Neutralization of Bauxite Residue by Carbon Dioxide  

Microsoft Academic Search

Bauxite residue red mud, an alkaline slurry from alumina refining, is produced in large volumes and disposed of in large surface impoundments. The objectives of this study were to measure the extent of neutralization of bauxite residue by carbon dioxide as a function of CO2 partial pressure and to determine the geochemical reactions responsible for carbon sequestration. Bauxite residue was

Sameer Khaitan; David A. Dzombak

2009-01-01

386

II. Greenhouse gas markets, carbon dioxide credits and biofuels17  

E-print Network

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

387

Electroreduction of carbon dioxide in aqueous solutions at metal electrodes  

SciTech Connect

The quantities of carbon stored in the form of atmospheric carbon dioxide, CO{sub 2} in the hydrosphere and carbonates in the terrestrial environment substantially exceed those of fossil fuels. In spite of this the industrial use of carbon dioxide as a source of chemical carbon is presently limited to preparation of urea and certain carboxylic acids as well as organic carbonates and polycarbonates. However, the situation is expected to change in the future, if effective catalytic systems allowing to activate carbon dioxide will become available. In this connection, the electrochemical reduction of CO{sub 2}, requiring only an additional input of water and electrical energy, appears as an attractive possibility. For more than 100 years formic acid and formates of alkali metals were considered as the only significant products of the electroreduction of carbon dioxide in aqueous solutions. The highest current efficiencies, exceeding 90 %, were obtained either with mercury or with amalgam electrodes. The only comprehensive study regarding kinetics of CO{sub 2} reduction in aqueous solution has been performed by Eyring et al. using a mercury cathode. This paper describes electrolysis studies.

Augustynski, J.; Jermann, B.; Kedzierzawski, P. [Univ. of Geneva (Switzerland)

1996-12-31

388

Assessing carbon dioxide emissions from energy use at a university  

Microsoft Academic Search

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

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

2009-01-01

389

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

Microsoft Academic Search

The objective of this project is to develop a simple, inexpensive process to separate CO as an essentially pure stream from a fossil fuel combustion system using a regenerable, sodium-based sorbent. The sorbent being used in this project is sodium carbonate which is converted to sodium bicarbonate, or ''baking soda,'' through reaction with carbon dioxide and water vapor. Sodium bicarbonate

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

2002-01-01

390

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

Microsoft Academic Search

The objective of this project is to develop a simple, inexpensive process to separate CO as an essentially pure stream from a fossil fuel combustion system using a regenerable, sodium-based sorbent. The sorbent being used in this project is sodium carbonate which is converted to sodium bicarbonate, ''baking soda,'' through reaction with carbon dioxide and water vapor. Sodium bicarbonate is

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

2001-01-01

391

Capturing carbon dioxide as a polymer from natural gas  

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

392

Distribution of and changes in industrial carbon dioxide production  

Microsoft Academic Search

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

Ralph M. Rotty

1983-01-01

393

Regeneration of oxygen from carbon dioxide and water.  

NASA Technical Reports Server (NTRS)

In a closed ecological system it is necessary to reclaim most of the oxygen required for breathing from respired carbon dioxide and the remainder from waste water. One of the advanced physicochemical systems being developed for generating oxygen in manned spacecraft is the solid electrolyte-electrolysis system. The solid electrolyte system consists of two basic units, an electrolyzer and a carbon monoxide disproportionator. The electrolyzer can reclaim oxygen from both carbon dioxide and water. Electrolyzer preparation and assembly are discussed together with questions of reactor design and electrolyzer performance data.

Weissbart, J.; Smart, W. H.; Wydeven, T.

1972-01-01

394

High-brightness all semiconductor laser at 1.57 ?m for space-borne lidar measurements of atmospheric carbon dioxide: device design and analysis of requirements  

NASA Astrophysics Data System (ADS)

The availability of suitable laser sources is one of the main challenges in future space missions for accurate measurement of atmospheric CO2. The main objective of the European project BRITESPACE is to demonstrate the feasibility of an all-semiconductor laser source to be used as a space-borne laser transmitter in an Integrated Path Differential Absorption (IPDA) lidar system. We present here the proposed transmitter and system architectures, the initial device design and the results of the simulations performed in order to estimate the source requirements in terms of power, beam quality, and spectral properties to achieve the required measurement accuracy. The laser transmitter is based on two InGaAsP/InP monolithic Master Oscillator Power Amplifiers (MOPAs), providing the ON and OFF wavelengths close to the selected absorption line around 1.57 ?m. Each MOPA consists of a frequency stabilized Distributed Feedback (DFB) master oscillator, a modulator section, and a tapered semiconductor amplifier optimized to maximize the optical output power. The design of the space-compliant laser module includes the beam forming optics and the thermoelectric coolers. The proposed system replaces the conventional pulsed source with a modulated continuous wave source using the Random Modulation-Continuous Wave (RM-CW) approach, allowing the designed semiconductor MOPA to be applicable in such applications. The system requirements for obtaining a CO2 retrieval accuracy of 1 ppmv and a spatial resolution of less than 10 meters have been defined. Envelope estimated of the returns indicate that the average power needed is of a few watts and that the main noise source is the ambient noise.

Esquivias, I.; Consoli, A.; Krakowski, M.; Faugeron, M.; Kochem, G.; Traub, M.; Barbero, J.; Fiadino, P.; Ai, Xiao; Rarity, J.; Quatrevalet, M.; Ehret, G.

2014-05-01

395

Persistent local order heterogeneity in the supercritical carbon dioxide  

E-print Network

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

Bolmatov, Dima; Gao, M; Zhernenkov, M

2014-01-01

396

Aesthetic management of gingival recession by root biomodification with carbon dioxide laser and subepithelial connective tissue graft with lateral repositioned flap technique  

PubMed Central

Localised gingival recessions continue to represent an important aesthetic condition requiring treatment in periodontics. Various techniques have been tried to treat exposed root surfaces to improve aesthetics with high percentage of success and minimal discomfort. Root biomodification is done to improve the predictability of these procedures. This clinical report describes periodontal plastic procedure involving subepithelial connective tissue graft with lateral repositioned flap technique and root biomodification with CO2 laser for the management of gingival recession. PMID:22778454

Rastogi, Pavitra Kumar; Lal, Nand; Garg, Nimit; Anand, Vishal; Singhal, Rameshwari

2012-01-01

397

Carbon dioxide, the feedstock for using renewable energy  

NASA Astrophysics Data System (ADS)

Extrapolation of world energy consumption between 1990 and 2007 to the future reveals the complete exhaustion of petroleum, natural gas, uranium and coal reserves on Earth in 2040, 2044, 2049 and 2054, respectively. We are proposing global carbon dioxide recycling to use renewable energy so that all people in the whole world can survive. The electricity will be generated by solar cell in deserts and used to produce hydrogen by seawater electrolysis at t nearby desert coasts. Hydrogen, for which no infrastructures of transportation and combustion exist, will be converted to methane at desert coasts by the reaction with carbon dioxide captured by energy consumers. Among systems in global carbon dioxide recycling, seawater electrolysis and carbon dioxide methanation have not been performed industrially. We created energy-saving cathodes for hydrogen production and anodes for oxygen evolution without chlorine formation in seawater electrolysis, and ideal catalysts for methane formation by the reaction of carbon dioxide with hydrogen. Prototype plant and industrial scale pilot plant have been built.

Hashimoto, K.; Kumagai, N.; Izumiya, K.; Kato, Z.

2011-03-01

398

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

PubMed

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

Tsuji, Yasushi; Fujihara, Tetsuaki

2012-10-14

399

Natural sources of greenhouse gases: carbon dioxide emissions from volcanoes  

USGS Publications Warehouse

Volcanic degassing of carbon dioxide plays an important role in keeping the atmosphere-ocean portion of the carbon geochemical cycle in balance. The atmosphere-ocean carbon deficit requires replenishment of 6??1012 mol CO2/yr, and places an upper limit on the output of carbon dioxide from volcanoes. The CO2 output of the global mid-oceanic ridge system is ca. 0.7??1012 mol/yr, thus supplying only a fraction of the amount needed to balance the carbon deficit. The carbon dioxide flux from subaerial volcanoes is poorly known, but it appears to be at least as large as the mid-oceanic ridge flux. Much (perhaps most) of the CO2 emitted from volcanoes is degassed noneruptively. This mode of degassing may lead to impacts on the environment and biosphere that are fundamentally different in character from those envisioned in published scenarios, which are based on the assumption that CO2 degassing occurs predominantly by eruptive processes. Although the flux of carbon dioxide from volcanoes is poorly constrained at present, it is clearly two orders of magnitude lower than the anthropogenic output of CO2.

Gerlach, Terrence

1990-01-01

400

Direct carbon dioxide emissions from civil aircraft  

NASA Astrophysics Data System (ADS)

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

Grote, Matt; Williams, Ian; Preston, John

2014-10-01

401

The influence of carbon dioxide on smoke formation and stability in methane-oxygen-carbon dioxide flames  

Microsoft Academic Search

The effect of replacing nitrogen in combustion air by carbon dioxide in a laminar, atmospheric methane diffusion flame was investigated experimentally and by numerical modelling. Measurements included flame temperature, carbon monoxide concentrations and direct observation and photographic investigation of the flame shape and behaviour. The experimental results indicate a substantial reduction of scattered light intensity and flame volume. When a

Douglas Hainsworth; M. Pourkashanian; Andrew P. Richardson; Joanne L. Rupp; Alan Williams

1996-01-01

402

Water and Carbon Dioxide Adsorption at Olivine Surfaces  

SciTech Connect

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

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

2013-11-14

403

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

PubMed

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

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

2013-03-15

404

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

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

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

2002-04-01

405

Master/Diploma project Degradation of carbon dioxide by micro organisms  

E-print Network

or storage of produced carbon dioxide. Unfortunately, applications based on fossil fuels cannot be improved for carbon dioxide neutral fuel, their efficiency for the above described industrial applications is to lowMaster/Diploma project Degradation of carbon dioxide by micro organisms The accumulation of carbon

Rostock, Universität

406

Carbon Dioxide Measurement and Tracking We are combining our expertise in remote sensing, measurement,  

E-print Network

Carbon Dioxide Measurement and Tracking We are combining our expertise in remote sensing, measurement, experimentation, and modeling to track and quantify CO2. 7 08 FACT SHEET Carbon Dioxide." Among the proposed solutions are carbon sequestration (storing carbon dioxide emissions in geologic

407

OPERATIONAL NOTE A SIMPLIFIED TRIPOD SUPPORT FOR USE WITH CARBON DIOXIDE  

E-print Network

OPERATIONAL NOTE A SIMPLIFIED TRIPOD SUPPORT FOR USE WITH CARBON DIOXIDE­ BAITED VECTOR surveillance trap support was designed as a tripod of polyvinyl chloride pipes to suspend carbon dioxide, vector surveillance, hanging traps, carbon dioxide, mosquito trap Carbon dioxide (CO2) emission is common

408

of carbon dioxide containing 12 but the low concentration of 14  

E-print Network

of carbon dioxide containing 12 C and 13 C, but the low concentration of 14 C has made its measurement in carbon dioxide extremely difficult. Using an ultrasensitive technique called saturated carbon at values well below radiocarbon's natural abundance in carbon dioxide. In their technique

Zare, Richard N.

409

Supercritical fluid carbon dioxide cleaning of plutonium parts  

SciTech Connect

Supercritical fluid carbon dioxide is under investigation in this work for use as a cleaning solvent for the final cleaning of plutonium parts. These parts must be free of organic residue to avoid corrosion in the stockpile. Initial studies on stainless steel and full-scale mock-up parts indicate that the oils of interest are easily and adequately cleaned from the metal surfaces with supercritical fluid carbon dioxide. Results from compatibility studies show that undesirable oxidation or other surface reactions are not occurring during exposure of plutonium to the supercritical fluid. Cleaning studies indicate that the oils of interest are removed from the plutonium surface under relatively mild conditions. These studies indicate that supercritical fluid carbon dioxide is a very promising cleaning medium for this application.

Hale, S.J.

1991-12-31

410

Heavy oil recovery process using cyclic carbon dioxide steam stimulation  

SciTech Connect

This patent describes a method of recovering oil from a subterranean formation containing viscous quality oil that is penetrated by at least one well in fluid communication with a substantial portion of the formation. The method consists of two principal component operations. The first operation is characterized in the patent in detail and consists of injecting a mixture of carbon dioxide and steam into the formation through the well. The ratio of carbon dioxide to steam in this infused mixture must be from 200-300 SCF carbon dioxide per barrel of steam (cold water equivalent) to produce the desired effect. The last operation described in the detailing of the method of recovery is the recovering of fluids, including oil, from the formation through the well.

Pebdani, F.N.; Shu, W.R.

1986-01-21

411

Fate of Fossil Fuel Carbon Dioxide and the Global Carbon Budget  

Microsoft Academic Search

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

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

1979-01-01

412

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

E-print Network

Regulation of Carbonic Anhydrase Expression by Zinc, Cobalt, and Carbon Dioxide in the Marine of carbonic anhydrase (CA) in the marine diatom Thalassiosira weissflogii. We have examined the roles for Zn in a CA. Our data also support the conclusion that TWCA1 plays a central role in carbon

Morel, François M. M.

413

Fate of fossil fuel carbon dioxide and the global carbon budget  

Microsoft Academic Search

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

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

1979-01-01

414

Reconciling glacial cycle atmospheric radiocarbon and carbon dioxide signatures  

NASA Astrophysics Data System (ADS)

The mechanisms causing the glacial-interglacial range of ~90ppmv are still not fully understood. The deep Pacific is a potential isolated storage reservoir of respired carbon related to reduced ocean ventilation at this time. During the initial deglaciation (18-14kyr BP), atmospheric carbon dioxide concentrations increased by ~40ppmv. Corresponding records of atmospheric radiocarbon concentration display a massive decrease of 190, which also suggest the sudden release of a large store of carbon that has been isolated from the atmosphere for a significant period of time. In this study we have used an Earth system model of intermediate complexity, GENIE (Grid ENabled Integrated Earth) to investigate the influence of plausible physical changes in ocean circulation on deep Pacific storage of carbon, and the impact on atmospheric carbon dioxide and distribution of carbon isotopes. We perform transient simulations of the last glacial cycle (120kyr) to examine the sensitivity of Pacific carbon storage to prescribed ocean circulations and sea-ice cover, including freshwater hosing to simulate Heinrich events. In particular we present modelled changes in carbon dioxide and radiocarbon, which produce deglacial changes consistent with available palaeo-records in terms of time scale and magnitude.

Felton, Michelle; Singarayer, Joy

2010-05-01

415

Investigating Diffusion and Entropy with Carbon Dioxide-Filled Balloons  

NASA Astrophysics Data System (ADS)

Fill an ordinary latex balloon with helium gas and you know what to expect. Over the next day or two the volume will decrease noticeably as helium escapes from the balloon. So what happens when a latex balloon is filled with carbon dioxide gas? Surprisingly, carbon dioxide balloons deflate at rates as much as an order of magnitude faster than helium balloons. An investigation into the details of this phenomenon provides students with an excellent opportunity to apply the kinetic theory of gases and the ideal gas law, and it can also be exploited for a dramatic in-class demonstration of diffusion and the second law of thermodynamics.

Jadrich, James; Bruxvoort, Crystal

2010-09-01

416

Carbon dioxidenitrogen separation through adsorption on activated carbon in a fixed bed  

Microsoft Academic Search

The reduction of carbon dioxide emissions from flue gases can be achieved using post-combustion capture technologies such as adsorption. In this paper, we report experimental data for the fixed-bed adsorption of carbon dioxide and nitrogen on activated carbon. The breakthrough curves were obtained at different temperatures 301306, 323, 373 and 423K using CO2\\/N2 mixtures. XPS and FTIR measurements

Tirzh L. P. Dantas; Francisco Murilo T. Luna; Ivanildo J. Silva Jr.; Diana C. S. de Azevedo; Carlos A. Grande; Alrio E. Rodrigues; Regina F. P. M. Moreira

2011-01-01

417

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

ERIC Educational Resources Information Center

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

Miyauchi, Takuya; Kamata, Masahiro

2012-01-01

418

Electrochemical cell for obtaining oxygen from carbon dioxide atmospheres  

NASA Technical Reports Server (NTRS)

For manned missions to Mars to become a reality, an efficient and reliable means of obtaining oxygen from the carbon dioxide-rich atmosphere will be required. Otherwise, the high cost of transporting the oxygen needed to sustain the astronauts will severely restrict the expedition to the martian surface. Recently, the use of electrochemical devices has been explored as a means of obtaining oxygen from the carbon dioxide-rich atmosphere. In these devices, oxygen ions diffuse through solid oxide membranes, thus, separating oxygen from the other gases presented. This phenomenon has only recently been explored as a means of obtaining large quantities of oxygen from toxic atmospheres, although first observed by Walter nernst in 1899. Nernst observed that stabilized zirconia will conduct oxygen ions when an electrical potential is applied across metallic electrodes applied to the ceramic membrane. Diatomic oxygen molecules are dissociated at the positive electrode/electrolyte interface. The oxygen ions enter the ceramic body due to the ion density gradient which is produced by the electrical potential across the electrolytic membrane. Once the ions have diffused through the membrane, they reform diatomic oxygen molecules at the anode. The separation of oxygen from carbon dioxide is achieved by the combination of thermal and electrochemical processes. The thermal decomposition of carbon dioxide (at 1000 C) results in the production of carbon monoxide and oxygen by the reaction.

Hooker, M. W.; Rast, H. E.; Rogers, D. K.

1989-01-01

419

21 CFR 201.161 - Carbon dioxide and certain other gases.  

Code of Federal Regulations, 2010 CFR

...Other Exemptions 201.161 Carbon dioxide and certain other gases. (a) Carbon dioxide, cyclopropane, ethylene, helium, and nitrous oxide gases intended for drug use are exempted from the requirements of 201.100(b) (2), (3),...

2010-04-01

420

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

E-print Network

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

de Weck, Olivier L.

421

Plausible Forms of Carbon Dioxide Ice Clouds in the Lower Atmosphere of Mars  

NASA Astrophysics Data System (ADS)

Observations supporting the suspected presence of clouds composed of carbon dioxide ice crystals in the lower atmosphere of Mars date to at least the early part of the Mars Global Surveyor (MGS) mission. Intriguing MOLA laser ranging results in the polar night indicate the nearly undeniable presence of populations of unidentified aerosol particles capable of reflecting or absorbing/scattering a significant portion of the near-infrared laser pulse. Furthermore, MGS radio science temperature retrievals in the polar night often exhibit regions aloft where the air temperature is significantly less than the carbon dioxide ice saturation temperature. Since observations able to concretely confirm or refute the existence of such clouds are still elusive, numerical models must be used to explore the hypothesis further. A microscale numerical model with detailed cloud microphysics capability should be able to provide valuable insight on the plausible form(s), environmental sensitivities, and climatic impacts of such carbon dioxide ice clouds. Results from investigations using such a model will be presented. This work is supported by a grant from the NASA Mars Fundamental Research Program.

Michaels, T.

2007-12-01

422

Continual production of glycerol from carbon dioxide by Dunaliella tertiolecta.  

PubMed

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

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

2013-05-01

423

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

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

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

2001-05-01

424

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

NASA Astrophysics Data System (ADS)

In correlation to climate change and CO2 emission different campaigns highlight the importance of forests and trees to regulate the concentration of carbon dioxide in the earths' atmosphere. Seeing millions of square miles of rainforest cut down every day, this is truly a valid point. Nevertheless, we often tend to forget what scientists like Spokes try to raise awareness for: The oceans - and foremost deep sea sections - resemble the second biggest deposit of carbon dioxide. Here carbon is mainly found in form of carbonate and hydrogen carbonate. The carbonates are needed by corals and other sea organisms to maintain their skeletal structure and thereby to remain vital. To raise awareness for the protection of this fragile ecosystem in schools is part of our approach. Awareness is achieved best through understanding. Therefore, our approach is a hands-on activity that aims at showing students how the carbon dioxide absorption changes in relation to the water temperature - in times of global warming a truly sensitive topic. The students use standard syringes filled with water (25 ml) at different temperatures (i.e. 10C, 20C, 40C). Through a connector students inject carbon dioxide (25ml) into the different samples. After a fixed period of time, students can read of the remaining amount of carbon dioxide in relation to the given water temperature. Just as with every scientific project, students need to closely monitor their experiments and alter their setups (e.g. water temperature or acidity) according to their initial planning. A digital template (Excel-based) supports the analysis of students' experiments. Overview: What: hands-on, minds -on activity using standard syringes to exemplify carbon dioxide absorption in relation to the water temperature (Le Chatelier's principle) For whom: adjustable from German form 11-13 (age: 16-19 years) Time: depending on the prior knowledge 45-60 min. Sources (extract): Spokes, L.: Wie Ozeane CO2 aufnehmen. Environmental Sciences. University of East Anglia, Norwich 2007. Von Borstel, G. und Bhm, A.: Le Chatelier einmal anders, Gleichgewichtsverschiebungen am Kontext Sprudelwasser. Naturwissenschaft im Unterricht Chemie 6 (2006) H. 96, S. 34-37

Meisinger, Philipp; Wittlich, Christian

2014-05-01

425

Carbon dioxide in clastic rocks and silicate hydrolysis  

Microsoft Academic Search

The amount of carbon dioxide in elastic rocks in sedimentary basins increases with depth. Organic matter, dissolved organic species, and dissolution of carbonate minerals have been suggested as sources of CO2, which increases in abundance with depth and temperature. Isotopic compositions of aqueous HCO-3, gaseous CO2 and calcite from conventional hydrocarbon wells and steam-assisted recovery of heavy oil suggest that

Ian Hutcheon; Hugh Abercrombie

1990-01-01

426

Photodissociation of carbon dioxide in the Mars upper atmosphere  

NASA Technical Reports Server (NTRS)

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

Barth, C. A.

1974-01-01

427

Thermodynamics of the carbon dioxide system in the oceans  

Microsoft Academic Search

In the next ten years, a number of studies on the carbonate system are planned as part of the JGOFS\\/WOCE programs. The carbon dioxide system will be studied by measuring at least two of the controlling parameters; pH, total alkalinity (TA), total inorganic CO2 (TCO2), and the fugacity of CO2 (fCO2). The other parameters can be calculated using thermodynamic relations.

Frank J. Millero

1995-01-01

428

Carbon Dioxide Capture from Flue Gas Using Dry, Regenerable Sorbents  

SciTech Connect

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

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

2006-03-31

429

Carbon Dioxide Capture from Flue Gas Using Dry Regenerable Sorbents  

Microsoft Academic Search

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

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

2007-01-01

430

Carbon dioxide emissions from fossil-fuel use, 1751 1950  

Microsoft Academic Search

Newly compiled energy statistics allow for an estimation of the complete time series of carbon dioxide (CO2) emissions from fossil-fuel use for the years 1751 to the present. The time series begins with 3106 metric tonnes carbon (C). This initial flux represents the early stages of the fossil-fuel era. The CO2 flux increased exponentially until World War I. The time

R. J. Andres; D. J. Fielding; G. Marland; T. A. Boden; N. Kumar; A. T. Kearney

1999-01-01

431

Thin film micro carbon dioxide sensor using MEMS process  

Microsoft Academic Search

Pt\\/Na+ ion conductive ceramic thin film\\/Pt\\/carbonate (Na2CO3:BaCO3=1:1.7mol) system CO2 micro gas sensor was fabricated and the sensing properties were investigated. The Na+ ion conductive thin film was prepared by RF magnetron sputtering method. The thin film micro carbon dioxide sensor was prepared by using silicon process combined with MEMS technology.A NASICON thin film (20002500) as main layer of the device

Yeung-Il Bang; Kap-Duk Song; Byung-Su Joo; Jeung-Soo Huh; Soon-Don Choi; Duk-Dong Lee

2004-01-01

432

40 CFR 86.1524 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2011 CFR

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

2011-07-01

433

40 CFR 86.1524 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

434

Using the 5E Learning Cycle Sequence with Carbon Dioxide  

ERIC Educational Resources Information Center

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

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

2007-01-01

435

DIRECT BIOLOGICAL EFFECTS OF INCREASED ATMOSPHERIC CARBON DIOXIDE LEVELS  

EPA Science Inventory

This report assesses the likely biological nonclimatic, direct effects of carbon dioxide (CO2) on terrestrial and aquatic ecosystems and on human health. It summarizes the current literature on the direct effects of rising CO2 levels on the biosphere and identifies technical info...

436

Carbon dioxide emissions and fossil fuel consumption a Canadian perspective  

Microsoft Academic Search

The potential climate change due to increased loading of carbon dioxide in the atmosphere has emerged as one of the most significant environmental threats of the late twentieth century. An analysis of a variety of feasible energy demand scenarios for Canada indicates that if we continue to consume the same types and proportions of fuels as we do today, the

John Peter Doucet

1988-01-01

437

Current inventory of anthropogenic carbon dioxide in the North Pacific  

Microsoft Academic Search

The atmospheric increase of carbon dioxide is the result of the burning of fossil fuels and massive deforestation currently underway. Since 1958, the atmosphere CO concentration has risen from about 315 ppm to about 343 ppm. The major repositories for anthropogenic CO are the oceans and the atmosphere. The distributions of freon-11, as a surrogate tracer, have been combined with

J. D. Cline; R. A. Feely; K. Kelly-Hansen; J. F. Gendron; D. P. Wisegarver

1985-01-01

438

Annual carbon dioxide drawdown and the Northern Annular Mode  

Microsoft Academic Search

Yeartoyear variations in summer drawdown of Northern Hemisphere atmospheric carbon dioxide (CO2) are compared with corresponding yeartoyear variations in sealevel pressure (SLP), surface air temperature, and the productivity of land vegetation as inferred from the satellitederived normalized difference vegetation index (NDVI). Annual values of CO2 drawdown for the years 19802000 are estimated from smoothed time series derived directly from individual

Joellen L. Russell; John M. Wallace

2004-01-01

439

Carbon Dioxide Production and Sodium Transport by the Toad Bladder  

Microsoft Academic Search

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

Roy H. Maffly; Cecil H. Coggins

1965-01-01

440

Carbon dioxide levels in the biosphere: Effects on plant productivity  

Microsoft Academic Search

Human society is now inadvertently conducting a great biological and environmental experiment, the outcome of which is not known. Atmospheric carbon dioxide (CO2) is increasing at the rate of 1.5 parts per million (ppm) per year. It has risen from 315 ppm to 340 ppm in the past 25 years a 9% increase. Because CO2 is among the factors

Sylvan H. Wittwer; Boyd R. Strain

1985-01-01

441

Classroom Carbon Dioxide Concentration, School Attendance, and Educational Attainment  

ERIC Educational Resources Information Center

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

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

2014-01-01

442

Carbon dioxide flash-freezing applied to ice cream production  

E-print Network

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

Peters, Teresa Baker, 1981-

2006-01-01

443

Raising the Level of Carbon Dioxide in Your Blood  

NSDL National Science Digital Library

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

Macleish, Marlene Y.; Mclean, Bernice R.

2013-05-15

444

A Discovery Experiment: Carbon Dioxide Soap Bubble Dynamics.  

ERIC Educational Resources Information Center

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

Millikan, Roger C.

1978-01-01

445

2004-01-2299 Elevated Carbon Dioxide Alters Hydrocarbon  

E-print Network

that are associated with a reduction in blood lipids, cholesterol and platelet activity2 , onion release a variety2004-01-2299 Elevated Carbon Dioxide Alters Hydrocarbon Emissions and Flavor in Onion P. W. Paré, R are grown at elevated CO2 compared to controls grown at ambient CO2 levels. Sensory panel taste testing has

Paré, Paul W.

446

Recent advances in catalyst immobilization using supercritical carbon dioxide  

Microsoft Academic Search

Homogeneous organometallic catalysts have a great potential for the development of sustainable synthetic processes. There is, however, an urgent need for the development of new techniques to separate products and catalysts efficiently, allowing for recycling and reuse of the precious catalyst. The unique solvent properties of supercritical carbon dioxide offer new approaches for the immobilization of organometallic catalysts, many of

Walter Leitner

2004-01-01

447

Role of carbon dioxide in cooling planetary thermospheres  

Microsoft Academic Search

A new value of the rate coefficient for the deactivation of the bending mode of carbon dioxide by atomic oxygen at low temperatures is derived from the observation of 15-micron emission from the atmosphere of the earth. This new value gives a cooling rate for the lower thermosphere that is two to three times the rate previously calculated, and it

Ramesh D. Sharma; Peter P. Wintersteiner

1990-01-01

448

Synthesis of epoxy ferrite nanocomposites in supercritical carbon dioxide  

Microsoft Academic Search

A series of epoxy ferrite nanocomposites (EFNCs) was synthesised through dispersing ferrite nanoparticles (5.0 phr, parts per hundred of resin) into diglycidylether of bisphenol A (0.1 mol) in supercritical carbon dioxide at 85 1C, 1600 psi over 1 h followed by curing with triethylene tetramine (15 phr) at 40 1C. For this purpose, ferrite nanoparticles were synthesised through

M. G. H. Zaidi; P. L. Sah; S. Alam; A. K. Rai

2009-01-01

449

Ocean acidification due to increasing atmospheric carbon dioxide  

E-print Network

Ocean acidification due to increasing atmospheric carbon dioxide Policy document 12/05 June 2005 ISBN 0 85403 617 2 This report can be found at www.royalsoc.ac.uk #12;Ocean acidification due.advice@royalsoc.ac.uk Copy edited and typeset by The Clyvedon Press Ltd, Cardiff, UK #12;Ocean acidification due

Levin, Lisa

450

Carbon Dioxide and Energy Exchanges in a Temperate Grassland Ecosystem  

Microsoft Academic Search

A micrometeorological study was conducted from May to October in 1987 to evaluate the surface exchanges of carbon dioxide and energy at a temperate grassland site in northeastern Kansas. The fluxes of CO_2 (F_{rm c}), latent heat (LE), sensible heat (H) and momentum were measured using the eddy correlation technique. Pertinent microclimatic, plant and soil variables were also monitored through

Joon Kim

1990-01-01

451

Elevated Carbon Dioxide Alters the Structure of Soil Microbial Communities  

E-print Network

Elevated Carbon Dioxide Alters the Structure of Soil Microbial Communities Ye Deng,a Zhili He that the soil microbial community composition and structure significantly altered under conditions of eCO2 and primary productivity (2, 19, 23), the impact of eCO2 on soil microbial communities remains poorly

Minnesota, University of

452

Carbon dioxide in soil profiles: Production and temperature dependence  

E-print Network

the diffusion of gas in response to a concentration gradient according to Fick's Law. In an ideal situationCarbon dioxide in soil profiles: Production and temperature dependence David Risk, Lisa Kellman 2002. [1] The temperature dependance of soil respiration has most commonly been addressed using surface

453

Degassing of metamorphic carbon dioxide from the Nepal Himalaya  

E-print Network

Degassing of metamorphic carbon dioxide from the Nepal Himalaya Matthew J. Evans Chemistry at the foot of the Higher Himalaya near the Main Central Thrust (MCT), Nepal Himalaya. We have sampled hot weathering for the Narayani River basin by a factor of four. Our study implies that the net impact

Derry, Louis A.

454

Ethanol as Fuel: Energy, Carbon Dioxide Balances, and Ecological Footprint  

Microsoft Academic Search

The major amtrihtitor to global wanning is considered to he the high levels of greenhouse gas emissions, especially carbon dioxide (COJ, caused by the burtiing of fossil fuel. Thus, to mitigate CO^ emissions, renewable energy sources such as ethanol have been seen as a promising alternative to fossil fuel consumption. Brazil was the world's first nation to run a large-scale

MARCELO E. DIAS DE OLIVEIRA; BURTON E. VAUGHAN; EDWARD J. RYKIEL JR

2005-01-01

455

The Effects of Acute Carbon Dioxide on Behavior and  

E-print Network

of non-neuronal cells to be sensitive to either increased levels of CO2/H1 or acid alone. CO2 affects and invertebrates show a similar response of rapid anesthesia with high levels of carbon dioxide. In this study, we the rapid unresponsiveness and cessation of an autonomic response. Hypoxic and low pH environments

Cooper, Robin L.

456

Corrosion of various engineering alloys in supercritical carbon dioxide  

E-print Network

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

Gibbs, Jonathan Paul

2010-01-01

457

Titanium dioxide based high temperature carbon monoxide selective sensor  

E-print Network

Titanium dioxide based high temperature carbon monoxide selective sensor Nancy O. Savagea , Sheikh of lanthanum oxide and copper oxide (labeled as ALC sensor), the sensor showed minimal response towards CH4 at elevated temperatures. Lanthanum oxide was used to inhibit the anatase to rutile transformation. Infrared

Dutta, Prabir K.

458

Global Warming: Carbon Dioxide and the Greenhouse Effect  

NSDL National Science Digital Library

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

Frontline/nova; Foundation, Wgbh E.; Domain, Teachers'

459

Solubility of fluoranthene, chrysene, and triphenylene in supercritical carbon dioxide  

Microsoft Academic Search

The solubility of polycyclic aromatic hydrocarbons in supercritical carbon dioxide is very low, and very little experimental data exist. A method has been developed for the measurement of such low solubilities, and the solubilities of fluoranthene, chrysene, and triphenylene in a temperature range 308.15 K to 328.15 K and in a pressure range 84 bar to 251 bar have been

Ligia Barna; Jean-Marie Blanchard; Evelyne Rauzy; Charles Berro

1996-01-01

460

Process Based Belowground Carbon Dioxide Modeling in a Desert Ecosystem  

NASA Astrophysics Data System (ADS)

We describe a study to integrate and assess biological and physical processes that govern belowground carbon dioxide levels at a semi-arid grassland near Canyonlands National Park. Carbon dioxide concentrations were measured every 30 minutes at 5 and 15 cm depth within the rooting zones of the two dominant grass species, Stipa hymenoides and Hilaria jamesii, as well as the interspace between the two. For Stipa hymenoides at 5 cm, a rain event caused belowground carbon dioxide levels to rise from 600 ppm to 2000 ppm with a response time of 8 hours, with a gradual return to quasi-steady state levels in subsequent days. A similar response was observed for H. jamesii. We developed and simulated a one-dimensional diffusion model with a production term for various types of CO2 production from the literature (either constant with increasing depth or a process based source). The process based production considered microbial and root respiration as well as the temperature dependence of soil respiration. Model inputs included volumetric soil water content, temperature and bulk density. Incorporating a process based production term led to high correlation between measured and modeled CO2 concentrations (r2 as high as 0.92). Our results indicate that carbon dioxide levels increased during rain events due to physical (not biological) processes as the soil saturated with water, and CO2 molecules diffused more slowly from the soil.

Zobitz, J. M.; Bowling, D. R.

2003-12-01

461

Carbon Dioxide Reduction to Methylamines under Metal-Free Conditions.  

PubMed

The first metal-free catalysts are reported for the methylation of amines with carbon dioxide. Proazaphosphatrane superbases prove to be highly active catalysts in the reductive functionalization of CO2 , in the presence of hydroboranes. The new methodology enables the methylation of N?H bonds in a wide variety of amines, including secondary amines, with increased chemoselectivity. PMID:25243949

Blondiaux, Enguerrand; Pouessel, Jacky; Cantat, Thibault

2014-11-01

462

Monthly, global emissions of carbon dioxide from fossil fuel consumption  

Microsoft Academic Search

This paper examines available data, develops a strategy and presents a monthly, global time series of fossil-fuel carbon dioxide emissions for the years 1950-2006. This monthly time series was constructed from detailed study of monthly data from the 21 countries that account for approximately 80% of global total emissions. These data were then used in a Monte Carlo approach to

Robert Joseph Andres; J. S. Gregg; London M Losey; Gregg Marland; Thomas A Boden

2011-01-01

463

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

E-print Network

demonstrates the connections between fossil fuel emissions, atmospheric carbon dioxide concentrations coupling that warming to global fossil fuel CO2 emissions. 1 #12;2 B. W. Rust Figure 1: Michael Crichton and Statistics, Vol. 37. Abstract In his recent novel, State of Fear (HarperCollins, 2004), Michael Crichton ques

Rust, Bert W.

464

Carbon Dioxide Absorption in a Membrane Contactor with Color Change  

ERIC Educational Resources Information Center

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

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

2010-01-01

465

Microbiological and Mineralogical Characterization of Columbia River Basalts Prior to Supercritical Carbon Dioxide Addition  

Microsoft Academic Search

Deep geologic sequestration of supercritical carbon dioxide can remove excess carbon dioxide from the atmosphere but will cause profound changes to the geochemistry and microorganisms in the deep strata where it is injected. Here we report the original subsurface microbial constituents in basalt aquifers where supercritical carbon dioxide will be injected as part of the DOE Big Sky Regional Partnership

F. S. Colwell; M. R. Fisk; H. Yip; A. Schwartz; B. R. Briggs; F. Spane

2009-01-01

466

Improving the Carbon Dioxide Emission Estimates from the Combustion of Fossil Fuels in California  

E-print Network

Improving the Carbon Dioxide Emission Estimates from the Combustion of Fossil Fuels in California Lawrence Berkeley National Laboratory October, 2008 Contract #05-310 "Improving the Carbon Dioxide Emission-310 "Spatial disaggregated estimate of energy-related carbon dioxide for California" #12;Acknowledgments

467

Ocean-atmosphere partitioning of anthropogenic carbon dioxide on centennial timescales  

E-print Network

approach for representing the partitioning of fossil fuel carbon dioxide in climate and earth systemOcean-atmosphere partitioning of anthropogenic carbon dioxide on centennial timescales Philip-atmosphere partitioning of anthropogenic carbon dioxide on centennial timescales is presented. The partial pressure

Follows, Mick

468

Carbon Dioxide Information Analysis Center (CDIAC) PRINCIPAL INVESTIGATOR: Thomas A Boden (CDIAC Di-  

E-print Network

;Carbon Dioxide Information Analysis Center (CDIAC) bon releases from fossil-fuel consumption at globalCarbon Dioxide Information Analysis Center (CDIAC) PRINCIPAL INVESTIGATOR: Thomas A Boden (CDIAC Di://cdiac.ornl.gov/ PROJECT DESCRIPTION The Carbon Dioxide Information Analysis Center (CDIAC) is the primary climate -change

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Effect of carbon dioxide on the performance of biogas\\/diesel duel-fuel engine  

Microsoft Academic Search

Methane and carbon dioxide are the two main constituents of biogas. Biogas also contains traces of nitrogen, hydrogen, oxygen and hydrogen sulphide. When diesel engine runs on biogas, the combustion is poor as compared to diesel fuel. One of the reason of poor combustion is the presence of carbon dioxide in the biogas. Percentage of methane and carbon dioxide in

Saiful Bari

1996-01-01

470

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

E-print Network

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

471

Exergy analysis of transcritical carbon dioxide refrigeration cycle with an expander  

E-print Network

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

Bahrami, Majid

472

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

E-print Network

A correlation of optimal heat rejection pressures in transcritical carbon dioxide cycles S.M. Liaoa) of transcritical carbon dioxide air-conditioning cycles. The analysis shows that the COP of the transcritical carbon dioxide cycle varies nonmonotonically with the heat rejection pressure; a maximum COP occurs

Zhao, Tianshou

473

Using supercritical carbon dioxide as solvent to replace water in polyethylene terephthalate (PET) fabric dyeing procedures  

Microsoft Academic Search

Dyeing fabrics in supercritical carbon dioxide (SCD) instead of water can save energy, reduce water use and prevent pollution. The special pilot plant was designed to test dyeing procedures in supercritical carbon dioxide and the analyses of the results indicate major benefits as compared to water based procedures. The dyeing of polyethylene terephthalate (PET) fabric in supercritical carbon dioxide using

Aiqin Hou; Bo Chen; Jinjin Dai; Kai Zhang

2010-01-01

474

Estimation of Methane and Carbon Dioxide Surface Fluxes using a 3-D Global Atmospheric  

E-print Network

Estimation of Methane and Carbon Dioxide Surface Fluxes using a 3-D Global Atmospheric Chemical@mit.edu Website: http://mit.edu/cgcs/ Printed on recycled paper #12;Estimation of Methane and Carbon Dioxide of Methane and Carbon Dioxide Surface Fluxes using a 3-D Global Atmospheric Chemical Transport Model by Yu

475

Control of sonoluminescence signal in deionized water using carbon dioxide S. Kumari a  

E-print Network

Control of sonoluminescence signal in deionized water using carbon dioxide S. Kumari a , M. Keswani damage Sonoluminescence Carbon dioxide Acoustic cavitation Cavitation threshold a b s t r a c t Megasonic processing of wafers. In this study, the ability of carbon dioxide to quench sonolumi- nescence generation

Deymier, Pierre

476

Fluid Phase Equilibria 226 (2004) 161172 Analysis of Henry's constant for carbon dioxide in water  

E-print Network

Fluid Phase Equilibria 226 (2004) 161­172 Analysis of Henry's constant for carbon dioxide in water of the Henry constant for carbon dioxide in water by Monte Carlo simulations over a broad range of temperatures for each species. Carbon dioxide is modelled by two three-site (EPM2, and Errington and Panagiotopoulos

Lisal, Martin