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1

Laser surgery: using the carbon dioxide laser.  

PubMed Central

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

Wright, V. C.

1982-01-01

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.

Ramsdell, William M.

2012-01-01

3

Treatment of condylomata acuminata with carbon dioxide laser.  

PubMed

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

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

1980-03-01

4

TIR1 carbon dioxide laser system for fusion  

Microsoft Academic Search

The paper examines the TIR-1 carbon dioxide laser system for fusion. The current efforts are concentrated on (1) the microsecond laser pulse plasma heating in solenoids and theta pinches, and (2) nanosecond CO2 laser utilization for inertial confinement fusion. The TIR-1 system was designed to develop nanosecond CO2 laser technology and to study laser-target interaction at 10 microns. This system

V. A. Adamovich; V. N. Anisimov; E. A. Afonin; V. Iu. Baranov; V. L. Borzenko; S. M. Kozochkin; D. D. Maliuta; Iu. A. Satov; A. Iu. Sebrant; Iu. B. Smakovski; A. N. Starostin; A. P. Streltzov; V. M. Petryakov; S. F. Chalkin

1980-01-01

5

Helios: A 15 TW carbon dioxide laser-fusion facility  

Microsoft Academic Search

Helios is an eight-beam carbon dioxide laser and target facility for the study of laser-fusion processes. The design of the laser is based on the principle of the electron-beam controlled high-pressure electrical discharge. The eight beams deliver a total of 9 kJ to targets in subnanosecond pulses and the peak intensity at focus exceeds 10¹⁶ W\\/cm²\\/beam. The laser can be

R. L. Carlson; J. P. Carpenter; D. E. Casperson; R. B. Gibson; R. P. Godwin; R. F. Jr. Haglund; J. A. Hanlon; E. L. Jolly; T. F. Stratton

1981-01-01

6

Carbon dioxide laser use in wound sealing and epikeratophakia.  

PubMed

This paper presents current clinical and experimental uses of the carbon dioxide laser and the results of our human and animal tissue fusion investigations. Trials were conducted with human scleral and corneal eye bank tissue and in albino rabbits. With power settings of 100 to 200 mW, optimal laser effect consisting of slight whitening and minimal edge shrinkage occurred between 10 and 70 mJ of total energy. No tissue adherence could be demonstrated with the parameters tested. A final study was made on the feasibility of sealing an epikeratophakia lenticle to its recipient bed using the carbon dioxide laser. The average force required to remove the button in the control experiments was 6.45 g and this increased to 6.99 g after laser treatment although no fusion was apparent. This was statistically significant (P less than .05). PMID:3108490

Keates, R H; Levy, S N; Fried, S; Morris, J R

1987-05-01

7

Carbon dioxide laser-assisted phonosurgery for benign glottic lesions  

Microsoft Academic Search

The objectives of the study were (1) to evaluate glottic function following carbon dioxide laser-assisted phonosurgery of\\u000a benign laryngeal disease, and (2) to assess postoperative glottic morphology and disease recurrence rates, using the study\\u000a design of comparative prospective non-randomized case series of patients with benign glottic pathology treated by laser-assisted\\u000a phonosurgery over 10years. 235 consecutive patients had pre- and postoperative

Marcel Geyer; Gian Peppino Ledda; Neil Tan; Peter A. Brennan; Roberto Puxeddu

2010-01-01

8

Sealed-Off Carbon Dioxide Laser.  

National Technical Information Service (NTIS)

In general, C02 lasers offer eminent oscillation efficiency and high output powers in comparison with other types of laser. On the other hand, CO2 lasers have a principal drawback of transient output power fall due to CO2 gas dissolution during discharge....

H. Ikeda T. Horishima T. Owaki

1988-01-01

9

Airborne Validation of Laser Remote Measurements of Atmospheric Carbon Dioxide  

Microsoft Academic Search

Future space missions to globally map atmospheric carbon dioxide (CO2) at all latitudes during the day and night, such as the ASCENDS (Active Sensing of CO2 Emissions over Night, Day, and Seasons) mission, will require high-precision laser measurements of CO2 columns across the troposphere from low Earth orbit. This paper discusses the development and measurement validation of a unique, multi-frequency,

Edward V. Browell; Jeremy Dobler; Susan A. Kooi; Yonghoon Choi; F. Wallace Harrison; Berrien Moore III; T. Scott Zaccheo

2010-01-01

10

First Airborne Laser Remote Measurements of Atmospheric Carbon Dioxide  

Microsoft Academic Search

A unique, multi-frequency, single-beam, laser absorption spectrometer (LAS) that operates at 1.57 mum has been developed for a future space-based mission to determine the global distribution of sources and sinks of atmospheric carbon dioxide (CO2). A prototype of the space-based LAS system was developed by ITT, and it has been successfully flight tested in five airborne campaigns conducted in different

E. V. Browell; M. E. Dobbs; J. Dobler; S. Kooi; Y. Choi; F. W. Harrison; B. Moore; T. S. Zaccheo

2008-01-01

11

Measurements of carbon dioxide absorption coefficients with a CO laser  

Microsoft Academic Search

Pressure dependences of carbon dioxide absorption coefficients for several CO laser transitions from 1850 to 1920 cm-1 are measured. A comparison with the calculations (HITRAN-91) has been made. The calculated data for the Q-branch (1880.994 cm-1) of the (2020)I-0110 CO2 band are 20% lower than the measured ones. In the P-branch (1932.472 cm-1) of the (1110) -00 degree(s)0) CO2 band

Vladimir N. Aref'ev; Yu. I. Baranov; K. N. Visheratin

1994-01-01

12

Carbon dioxide laser oral safety parameters for teeth  

SciTech Connect

The carbon dioxide laser is used in the oral cavity for a variety of procedures. Although the procedures may not involve the teeth directly, precaution should be exercised to preserve their integrity. The results of this study indicate that the most limiting parameter for oral use of the CO{sub 2} laser is damage to the enamel surface, which could be inflicted with as little as 5 W for 0.2 second and a 1 mm beam. Care should be exercised to prevent inadvertent damage to the surface enamel of teeth even at very low energy levels.

Powell, G.L.; Whisenant, B.K.; Morton, T.H. (Univ. of Utah, Salt Lake City (USA))

1990-01-01

13

a Blackbody-Pumped Carbon Dioxide Laser  

NASA Astrophysics Data System (ADS)

A proof of concept experiment has been carried out to demonstrate the feasibility of using blackbody radiation to pump a gas laser. Building on earlier experiments in which optical gain was measured in a CO(,2) laser mixture exposed to blackbody radiation at a temperature of 1500(DEGREES)K, continuous wave oscillation of CO(,2) has been achieved, for the first time, using radiation from a blackbody cavity as the pump source. This was made possible by actively cooling the laser mixture as it was exposed to the radiation field of an electrically heated oven. Output power measurements are presented from a series of experiments using mixtures of CO(,2), He, and Ar. Maximum output power was obtained with a 20%CO(,2) - 15%He- 65%Ar mixture at pressures around 6-10 Torr. The output power was found to vary greatly with the gas temperature and the blackbody temperature. By varying these parameters output powers up to 8 mW have been achieved. The effects of the buffer gas are also shown to be important. Based on the experimental results, it is believed that the buffer gas is needed to inhibit diffusion of the excited species out of the laser mode volume. This diffusion leads to deactivation at the walls. Adding more CO(,2) results in a decrease in output power, indicating that the gas has a finite optical depth and the mode volume is not pumped if too much CO(,2) is present. A model which incorporates these effects is presented. The predicted small signal gains and powers based on this model adequately match the trends observed experimentally.

Insuik, Robin Joy

14

Effective treatment of nodular amyloidosis with carbon dioxide laser.  

PubMed

BACKGROUND: Nodular amyloidosis is a rare form of localized cutaneous amyloidosis that is characterized by nodules located on the extremities, trunk, genitalia, or face. In treatment regimens, many approaches have been described, including carbon dioxide (CO2) laser therapy. OBJECTIVE:We present a case of a 60-year-old white male with a 20-year history of disseminated waxy, purpuric, yellowish, and bullous skin lesions on the trunk and extremities. The skin changes were accompanied by pain during palpation and were temporarily pruritic. METHOD:Based on histologic and direct immunofluorescence test findings, the diagnosis of cutaneous nodular amyloidosis was established. Skin lesions were treated with a CO2 laser. During surgery, treated tissue was found to be slightly friable, and there was a little problem with hemostasis that correlated with amyloid infiltration of the dermis and blood vessels. However, after 8 weeks, we observed clinical improvement of all treated areas with the presence of atrophic scars. In the regions of laser therapy, no recurrence of the disease was observed during a 12-month follow-up. ConcluSION:Based on these results, we conclude that CO2 laser has a beneficial effect in the treatment of nodular amyloidosis; however, surgery procedures may be associated sometimes with tissue friability and poor hemostasis. PMID:22971317

Lesiak, Aleksandra; Rakowski, Adam; Brzezinska, Agnieszka; Rogowski-Tylman, Micha?; Kolano, Pawel; Sysa-Jedrzejowska, Anna; Narbutt, Joanna

15

Recent Results From, and Future Plans for the JPL Carbon Dioxide Laser Absorption Spectrometer  

Microsoft Academic Search

The Carbon Dioxide Laser Absorption Spectrometer (CO2LAS) is an aircraft based Integrated Path Differential Absorption (IPDA) Spectrometer operating in the 2 micron wavelength range that we have been developing at JPL to evaluate the measurement of the column integrated carbon dioxide concentration beneath the aircraft. The IPDA measurement technique is based on an approach first used for the measurement of

G. D. Spiers; R. Menzies; S. Geier; M. Phillips

2009-01-01

16

First Airborne Laser Remote Measurements of Atmospheric Carbon Dioxide for Future Active Sensing of Carbon Dioxide from Space  

Microsoft Academic Search

Future space missions to globally map atmospheric carbon dioxide (CO2) at all latitudes during the day and night, such as the ASCENDS (Active Sensing of CO2 Emissions over Night, Day, and Seasons) mission, will require high-precision laser measurements of CO2 columns across the troposphere from low Earth orbit. This paper discusses the development and flight demonstration of a unique, multi-frequency,

E. V. Browell; M. E. Dobbs; J. Dobler; S. A. Kooi; Y. Choi; F. W. Harrison; B. Moore III; T. S. Zaccheo

2009-01-01

17

Cell Migration and Proliferation During Repair of Superficial Corneal Wounds Produced by a Carbon Dioxide Laser.  

National Technical Information Service (NTIS)

Superficial wounds were produced in the rabbit corneal epithelium by a 2-mm. circular beam from a carbon dioxide laser. The healing response of the epithelium was examined histologically in tritiated thymidine radioautographs at various times following wo...

D. J. Lehmiller

1970-01-01

18

21 CFR 874.4500 - Ear, nose, and throat microsurgical carbon dioxide laser.  

Code of Federal Regulations, 2013 CFR

...CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Surgical Devices § 874.4500 Ear, nose, and throat microsurgical...microsurgical carbon dioxide laser is a device intended for the surgical excision of tissue from the ear, nose, and throat...

2013-04-01

19

Low-fluence carbon dioxide laser irradiation of lentigines  

SciTech Connect

Low-fluence carbon dioxide (CO2) laser irradiation of skin has previously been shown to induce damage limited primarily to the epidermis. To evaluate whether this technique was therapeutically effective for pigmented epidermal lesions, ten lentigines caused by methoxsalen and ultraviolet light therapy were treated in one patient using the CO2 laser at fluences ranging from 3.0 to 7.7 J/cm2 for 0.1-s exposures with 4.5-mm spot size. Based on substantial clearing in seven of ten lesions treated, 146 solar lentigines were treated in five patients at fluences of 3.0, 3.7, or 4.4 J/cm2. Biopsies were performed on a total of 30 lesions immediately and 24 hours, seven days, and six weeks after irradiation. Of 125 lesions followed up clinically for six weeks, 12 cleared completely, 81 lightened substantially, and 28 remained unchanged. Only two demonstrated atrophic change. Hyperpigmentation or hypopigmentation did not occur. All lesions that improved had been treated at 3.7 or 4.4 J/cm2. Immediate histologic injury consisted of vacuolar and spindly change and subsequent vesiculation limited to the basilar epidermis. Twenty-four hours later there was epidermal necrosis with regeneration, 0.1 mm of dermal basophilia and stromal condensation, and a mild inflammatory infiltrate. These alterations were dose-dependent, with near complete epidermal necrosis and superficial dermal involvement at the highest fluence, and only focal epidermal necrosis at the lowest. At seven days, epidermal regeneration was complete with traces of melanin remaining in keratinocytes. Melanophages first appeared at seven days and persisted at six weeks, by which time the inflammatory infiltrate had cleared. No lentiginous proliferation was evident and epidermal pigmentation had become normal. Low-fluence CO2 laser irradiation is an effective means of damaging the epidermis with only minimal dermal change.

Dover, J.S.; Smoller, B.R.; Stern, R.S.; Rosen, S.; Arndt, K.A.

1988-08-01

20

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

21

Pilot Ultrastructural Evaluation of Human Preauricular Skin Before and After High-Energy Pulsed Carbon Dioxide Laser Treatment  

Microsoft Academic Search

Background: Carbon dioxide laser resurfacing has re- cently come into favor for the treatment of photodam- aged skin. While the clinical and histologic effects of high- energy short-pulse carbon dioxide lasers on human skin have been investigated, the ultrastructural effects of these lasers have not been documented. Our objective was to study the ultrastructural effects of a high-energy pulsed carbon

Desiree Ratner; Annie Viron; Francine Puvion-Dutilleul; Edmond Puvion

1998-01-01

22

Carbon dioxide laser therapy for an inflammatory linear verrucous epidermal nevus: a case report.  

PubMed

The treatment of an inflammatory linear verrucous epidermal nevus (ILVEN), an uncommon type of epidermal nevus, is still controversial. The use of laser therapy is a recently reported method. Although various results have been reported with the use of the laser in the treatment epidermal nevis, the authors have not seen any report on the use of the carbon dioxide laser in ILVEN treatment. They present case of ILVEN treated with the carbon dioxide laser. All symptoms (erythema, excoriation, granulation, and pruritus) disappeared. Instead, a pale pigmentation was seen. PMID:15583849

Ulkur, Ersin; Celikoz, Bahattin; Yuksel, Fuat; Karagoz, Huseyin

2004-12-02

23

Recent Results From the JPL Carbon Dioxide Laser Absorption Spectrometer  

Microsoft Academic Search

Active optical sensing of atmospheric molecular species relies on measuring the differential absorption between a number of different wavelengths to determine changes in concentration of the species of interest. At JPL we have been developing an aircraft instrument that uses an Integrated Path Differential Absorption (IPDA) approach in the 2-micron spectral region for high-precision measurements of atmospheric carbon dioxide mixing

G. D. Spiers; S. Geier; M. W. Phillips; R. T. Menzies

2007-01-01

24

Clinical applications of the Argon and carbon dioxide lasers in dermatology and plastic surgery  

Microsoft Academic Search

Since the 1960's, thousands of skin and soft tissue malformations have been treated with the Argon and carbon dioxide lasers. The Argon laser, emitting blue-green light, is very useful for treating port wine hemangiomas and other cutaneous vascular abnormalities; it has also been applied to a variety of nonvascular skin lesions. Its mechanism of action is essentially heat coagulation.

Morton R. Maser; David B. Apfelberg; Harvey Lash

1983-01-01

25

Carbon Dioxide Laser Therapy for an Inflammatory Linear Verrucous Epidermal Nevus: A Case Report  

Microsoft Academic Search

The treatment of an inflammatory linear verrucous epidermal nevus (ILVEN), an uncommon type of epidermal nevus, is still controversial. The use of laser therapy is a recently reported method. Although various results have been reported with the use of the laser in the treatment epidermal nevis, the authors have not seen any report on the use of the carbon dioxide

Ersin Ulkur; Bahattin Celikoz; Fuat Yuksel; Huseyin Karagoz

2004-01-01

26

Endoscopic Carbon Dioxide Laser Division of Congenital Complete Tracheal Rings: A New Operative Technique  

Microsoft Academic Search

A carbon dioxide laser was used through a bronchoscope to split the posterior aspect of complete tracheal rings in the distal trachea of a 16-month-old boy previously palliated for cyanotic congenital heart disease. After laser division of the complete tracheal rings, the patient was successfully extubated. Subsequently, the boy had granulation tissue develop, which required bronchoscopic resection, and then severe

W. Andrew Clement; Neil K. Geddes; Crispin Best

2005-01-01

27

21 CFR 179.43 - Carbon dioxide laser for etching food.  

Code of Federal Regulations, 2013 CFR

...food under the following conditions: (a) The radiation source consists of a carbon dioxide laser designed to emit pulsed infrared radiation with a wavelength of 10.6 micrometers such that the maximum energy output of the laser does not exceed 9.8 ...

2013-04-01

28

Airborne Validation of Laser Remote Measurements of Atmospheric Carbon Dioxide  

NASA Astrophysics Data System (ADS)

Future space missions to globally map atmospheric carbon dioxide (CO2) at all latitudes during the day and night, such as the ASCENDS (Active Sensing of CO2 Emissions over Night, Day, and Seasons) mission, will require high-precision laser measurements of CO2 columns across the troposphere from low Earth orbit. This paper discusses the development and measurement validation of a unique, multi-frequency, single-beam, laser absorption spectrometer (LAS) that operates at 1.57 ?m, which has been developed for a future space-based mission to determine the global distribution of regional-scale CO2 sources and sinks. A prototype of this space-based LAS system was developed by ITT, and it has been flight tested in eight airborne campaigns conducted over the last five years in Oklahoma, Michigan, New Hampshire, and Virginia under a wide range of atmospheric conditions. This paper focuses on the results obtained during the last two years of flight testing where the remote LAS measurements of CO2 were evaluated against high-quality airborne in situ CO2 measurements made on spirals near the center of the LAS flight tracks. Flight tests over various land and water regions of Virginia in October 2007 showed the high correlation (R2 = 0.995) of the LAS-measured CO2 optical depths (ODs) with altitude, and a high correlation (R2 = 0.996) between the remote and in situ-derived (modeled) CO2 ODs. The average difference between measured and modeled ODs was less than 0.33% or the equivalent of about 1.25 ppmv of CO2. The LAS measurement precision for a 10-s (1 km) average over land was found to be better than 0.7 ppmv and over water was better than 1.4 ppmv. During the flight tests in September-October 2008, improvements in the in situ sampling strategy were implemented, and the average difference between the measured and modeled CO2 ODs was found to be 0.11% or 0.42 ppmv. A comprehensive multiple-aircraft flight test program was conducted over Oklahoma and Virginia in July-August 2009, and this resulted in an average difference between the remote and in situ CO2 ODs for all six flights at all altitudes of 0.10% or 0.40 ppmv with a standard deviation of the results of 0.64% or 2.5 ppmv. LAS instrument improvements also led to a 10-s CO2 measurement precision over land of better than 0.2 ppmv and over water of better than 0.3 ppmv. These high-precision, high-accuracy active remote CO2 measurements represent a major step towards the realization of the needed capability for space-based laser measurements of the global distribution of CO2. Details of the LAS flight tests and comparisons of the observed and modeled CO2 measurements are discussed in this paper.

Browell, Edward V.; Dobler, Jeremy; Kooi, Susan A.; Choi, Yonghoon; Harrison, F. Wallace; Moore, Berrien, III; Zaccheo, T. Scott

2010-05-01

29

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

SciTech Connect

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

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

1987-06-01

30

[Advancement in the research of fractional carbon dioxide laser in treating burn scars].  

PubMed

This paper reviews the new progress in the research of fractional carbon dioxide laser in treating hypertrophic scar after burn injury, which remains a challenging problem for burn care surgeons. There have been many traditional therapeutic approaches, such as compression remedy, operation, and so on. However, a satisfactory method is lacking to date. In recent years, the newly developed fractional carbon dioxide laser has been employed to treat different kinds of scars, and it has been proved to be effective in terms of an improvement of scar color, texture, and rigidity. It seems to be a promising method for scar treatment in future. PMID:23327918

Wang, Hai-bo; Fang, Yong; Yu, Wei-rong

2012-12-01

31

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

32

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

PubMed

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

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

2001-12-01

33

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

Microsoft Academic Search

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

Eric M Finley; John Louis Ratz

1996-01-01

34

Application of a carbon dioxide laser for early closure of gingival flaps  

Microsoft Academic Search

The aim of this study was to evaluate the applicability of a carbon dioxide (CO2) laser as a means of achieving early closure of gingival flaps after periodontal surgery. In this study, an incision was made from the maxillary premolar to the canine tooth in dogs. Full thickness flaps were raised, and mucoperiosteal flaps were created. After repositioning the mucoperiosteal

Soh Sato; Hisahiro Kamoi; Yoshiko Wasaki; Kyuichi Kamoi

2003-01-01

35

Subglottic stenosis in Wegener's granulomatosis: development during cyclophosphamide treatment with response to carbon dioxide laser therapy  

Microsoft Academic Search

A patient with Wegener's granulomatosis rapidly developed a circumferential subglottic stenosis while on a cyclophosphamide regimen that had caused resolution of systemic symptoms and pulmonary infiltrates. The stenosis developed in the area of previously noted tracheal ulceration and responded satisfactorily to carbon dioxide laser therapy.

C Strange; L Halstead; M Baumann; S A Sahn

1990-01-01

36

Treatment of Bowen's disease of the digit with carbon dioxide laser  

Microsoft Academic Search

Background: Therapy for Bowen's disease is essential to prevent invasive squamous cell carcinoma and metastases. Surgical excision is preferred because of the low relapse rate, but it may result in scar contracture, especially in the digit. Objective: This study was undertaken to evaluate the effectiveness of carbon dioxide laser for Bowen's disease of the digit. Methods: Patients with biopsy-proven Bowen's

Niyom Tantikun

2000-01-01

37

Papillomavirus in the vapor of carbon dioxide laser-treated verrucae  

Microsoft Academic Search

Vapor produced by the carbon dioxide laser during the vaporization of papillomavirus-infected verrucae was analyzed for viral DNA content. Two models were used for evaluation: an in vitro cutaneous bovine fibropapilloma and an in vivo human verruca model. Four bovine fibropapillomas were exposed to various laser parameters with power densities of 38,200 to 130 W\\/cm2 and energy fluences of 3820

J. M. Garden; M K OBanion; L S Shelnitz; K S Pinski; A D Bakus; M E Reichmann; J P Sundberg

1988-01-01

38

Stimulated Raman Scattering Laser Oscillation around 1.6 mum Carbon Dioxide Absorption Line  

Microsoft Academic Search

A solid-state stimulated Raman scattering (SRS) laser oscillation around the 1.6 mum carbon dioxide absorption lines is demonstrated. The stokes output of the SRS radiation at 1.57 mum is generated from the frequency conversion of the 1.35 mum laser radiation of Nd3+:KGd(WO4)2 (Nd:KGW) in the cavity. The maximum output energy was 13.8 mJ with a repetition rate of 10 Hz,

Daisuke Sakaizawa; Chikao Nagasawa; Tomohiro Nagai; Makoto Abo; Yasukuni Shibata; Masahisa Nakazato

2008-01-01

39

Indirect ignitioin of the endotracheal tube during carbon dioxide laser surgery.  

PubMed

We report here a case of an endotracheal tube fire occurring during carbon dioxide (CO2) laser surgery in the path of gases that support combustion. The tube was thought to be ignited by flaming tissue in close proximity to the tip and not directly by the laser. Tubes 1 cm away from an object repeatedly hit by the laser an easily be ignited indirectly. Aluminum-tape wrapping does not prevent this complication. We recommend caution when using the CO2 laser in the path of combustible gases in the presence of flammable objects. PMID:7417094

Hirshman, C A; Smith, J

1980-10-01

40

Analysis of plume emissions after papovavirus irradiation with the carbon dioxide laser  

SciTech Connect

This study was undertaken to evaluate potential inhalation hazards to operating room personnel after irradiation of tumors with the carbon dioxide laser. Cellular debris was analyzed for viability using labeled nucleotides and labeled glucose. In this way the plume was investigated for the presence of material with oncogenic potential. Most surgeons who have ablated venereal warts or certain tumors with the carbon dioxide laser have worried about possible hazards of inhaling the vapor that is produced as a result of their work. We utilized three methods to determine whether viable particles exist in the laser plume. Fortunately, it is most comforting that the metabolic studies, DNA and RNA studies and cytologic studies seem to indicate that the plume is biologically inactive.

Bellina, J.H.; Stjernholm, R.L.; Kurpel, J.E.

1982-05-01

41

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

PubMed

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

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

1982-12-01

42

Accelerated healing of carbon dioxide laser burns in rats treated with composite polyurethane dressings.  

PubMed

Healing time, infection rate, and residual scar formation were compared in carbon dioxide laser burns in rats treated in four ways: Spandra composite dressing, OpSite composite dressing, Petrolatum Gauze (USP), and no treatment. There were no infections and no differences in scar formation among the treatment groups. The mean healing times were ten days for the polyurethane dressings (Spandra and OpSite), 13 days for Petrolatum Gauze, and 16 days for the untreated group. Spandra was easier to apply and handle than OpSite. These findings suggest that synthetic gas-permeable dressings promote healing after cutaneous carbon dioxide laser surgery more effectively than conventional treatments of ointment-impregnated gauze or leaving the wound exposed to the air. PMID:3115190

Chan, P; Vincent, J W; Wangemann, R T

1987-08-01

43

Saline soaked pledgets prevent carbon dioxide laser-induced endotracheal tube cuff ignition  

Microsoft Academic Search

Study Objective: To determine whether saline soaked pledgets would protect the cuffs of polyvinylchloride (PVC) endotracheal tubes from carbon dioxide (CO2) laser-induced combustion.Design: 12 PVC endotracheal tubes were studied. The cuffed end of each was placed in a graduated cylinder and flushed with 5 L\\/min of oxygen for 5 minutes. The endotracheal tube's cuff was then inflated with air and

Mitchel B. Sosis

1995-01-01

44

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

SciTech Connect

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

Viswanathan, V.K.

1981-01-01

45

A clinical and histologic comparison of electrosurgical and carbon dioxide laser peels  

Microsoft Academic Search

Background: A radiofrequency-controlled electrosurgical device (ESD) has been adapted for skin peeling. A high-voltage, low-amperage current converts an irrigant into an ionized vapor, causing molecular dissociation and superficial damage in adjacent tissue. Objective: We compared the clinical and histologic effects of a scanning carbon dioxide (CO2) laser (ESC\\/Sharplan 40C) and the ESD (Visage Cosmetic Surgery System, Arthrocare). Methods: This study

K. M. Acland; E. Calonje; P. T. Seed; C Stat; R. J. Barlow

2001-01-01

46

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

2012-02-10

47

A Case of Angiokeratoma Circumscriptum of the Tongue: Response with Carbon Dioxide and Pulsed Dye Laser  

PubMed Central

Solitary angiokeratoma circumscriptum (AC) of the tongue is a rare entity. We present a case of solitary AC over the ventral surface of the tongue present for 3 years. The patient was treated with a combination of carbon dioxide (CO2) and pulsed dye laser (PDL). There was more than 75% improvement in the lesion after treating with alternate sessions of CO2 and PDL.

Kar, Hemanta Kumar; Gupta, Lipy

2011-01-01

48

Use of Zernike Polynomials and Interferometry in the Optical Design and Assembly of Large Carbon-Dioxide Laser Systems.  

National Technical Information Service (NTIS)

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 construc...

V. K. Viswanathan

1981-01-01

49

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

Microsoft Academic Search

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

Viswanathan

1981-01-01

50

Use of the carbon dioxide laser in the drainage of subretinal fluid  

SciTech Connect

Hemorrhage and retinal perforation are two sight-threatening complications associated with techniques employed to drain subretinal fluid in rhegmatogenous retinal detachment. We hypothesized that the carbon dioxide (CO/sub 2/) laser would reduce these complications because of its cauterizing action and high absorption in water. The CO/sub 2/ laser was compared with a conventional technique of using a penetrating diathermy electrode to drain subretinal fluid in rabbits with experimentally detached retinas. No hemorrhage occurred in 223 drainage trials using the CO/sub 2/ laser, whereas hemorrhage occurred in 21 (4.8%) of 434 trials using the penetrating diathermy electrode. Furthermore, a depth of saline of only 45 microns protected the retina from perforation at CO/sub 2/ laser dose adequate for drainage. These results indicate that further evaluation of the CO/sub 2/ laser in treating human retinal detachment is warranted.

Engel, J.M.; Blair, N.P.; Harris, D.; Baker, D.S.

1989-05-01

51

Carbon dioxide laser effects on caries-like lesions of dental enamel  

NASA Astrophysics Data System (ADS)

Previous studies by the authors have shown that carbon dioxide (CO2) laser light has marked effects on dental hard tissues and that these effects are wavelength-dependent. The aim of the present study was to determine whether treatment by CO2 laser of caries-like lesions in human enamel would inhibit subsequent lesion progression. Nine groups of 10 teeth each with preformed caries-like lesions were treated with/without CO2 laser (9.32 micrometers , 15 mJ or 25 mJ per pulse) by a pulsed laser (100-200 nsec) for either 200 or 400 pulses. Preformed lesions were then treated with acidulated phosphate fluoride for 5 minutes with control groups with no fluoride treatment. Teeth were subjected to a subsequent pH cycling challenge to determine the protection against lesion progression. Low energy laser treatment coupled with fluoride treatment entirely inhibited subsequent lesion progression in this model system.

Featherstone, John D.; Zhang, S. H.; Shariati, M.; McCormack, Sandra M.

1991-05-01

52

Treatment of multiple eruptive vellus hair cysts with carbon dioxide laser vaporization and manual lateral pressure.  

PubMed

Treatment of eruptive vellus hair cysts (EVHC) is often unsatisfactory. Laser treatment has been described as an adequate treatment in a few reports. Pulsed carbon dioxide (CO(2)) laser has been used effectively for facial EVHC and erbium:yttrium-aluminium-garnet laser has been used to treat truncal EVHC with variable outcomes. We report our experience with CO(2) laser and lateral manual pressure to extract the cysts as an effective treatment in two cases of EVHC. Good cosmetic results were obtained in both cases. No lesion recurrence was observed after a follow-up of 10 years in the first case and 3 years in the second one. CO(2) laser vaporization and further extraction of cysts by manual lateral pressure might be an effective method to treat EVHC, achieving good cosmetic results and no recurrence. PMID:19663855

Fernndez-Torres, R; Del Pozo, J; Castieiras, I; Sacristn, F; Mazaira, M; Fonseca, E

2009-07-29

53

Treatment of Facial Lesions of Multicentric Reticulohistiocytosis by Carbon Dioxide Laser  

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 esthetic, cosmetic, and rejuvenation segments. We report a case of multicentric reticulohistiocytosis with cosmetically disfiguring confluent papules over the scalp, forehead, nasolabial folds, chin, and retroauricular region. We used CO2 laser in superpulse mode for ablating the lesions in three sittings. The lesions regressed completely and no recurrence was observed over a regular follow-up of 8 months.

Mahajan, Rashmi S; Shah, Aishani C.; Nagar, Amit; Freny, Bilimoria E

2013-01-01

54

Treatment of burn scar using a carbon dioxide fractional laser.  

PubMed

In Asian patients, ablative laser therapies are seldom used to treat burn scars due to posttreatment dyschromia, especially when nonfacial areas are treated. The non-ablative 1550-nm erbium-doped fractional photothermolysis system, although effective, requires multiple treatment sessions. In the authors hands, a 34-year-old Korean woman achieved improved atrophy, contracture, texture and color of a burn scar on her chest after two treatments spaced six weeks apart with an ablative 10,600 nm CO2 fractional laser system (Ultrapulse Encore Laser, Lumenis Inc., Santa Clara, CA). PMID:20214184

Cho, Sung Bin; Lee, Sang Ju; Chung, Won Soon; Kang, Jin Moon; Kim, Young Koo

2010-02-01

55

Carbon dioxide lasers. Citations from the NTIS data base  

NASA Astrophysics Data System (ADS)

Citations on theory, design, operation, output and diagnostics of CO2 lasers are presented. Studies relating to excitation, frequency conversion, modulation, laser pumping, reaction kinetics, gas dynamics, and plasmas are included. The development and efficiency of optical components such as mirrors, resonators, tuning devices, infrared optical materials, amplifiers, and gratings are also discussed. This updated bibliography contains 214 citations, 70 of which are new entries to the previous edition.

Cavagnaro, D. M.

1980-10-01

56

TIR-1 carbon dioxide laser system for fusion.  

PubMed

During recent years pulsed CO(2) lasers for fusion research have been under construction in the I. V. Kurchatov Institute of Atomic Energy and the D. V. Efremov Electro-Physical Apparatus Institute. Efforts are being concentrated at present on two approaches: (1) microsecond laser pulse plasma heating in solenoids and theta pinches (UTRO system) and (2) nanosecond CO(2) laser utilization for inertial confinement fusion. The TIR-1 system was created to develop nanosecond CO(2) laser technology and to study laser-target interaction at 10 microm. This system is designed to deliver ~1-kJ energy in one beam of ~l-nsec duration. The TIR-1 system consists of an oscillator-preamplifier system that produces an ~1-nsec laser pulse with an energy contrast ratio of ~10(6), a large-aperture (30 x 30-cm(2)) triple-pass amplifier capable of providing approximately 1 kJ in a 1-nsec pulse, a target chamber with diagnostic equipment, and associated engineering systems. PMID:20220959

Adamovich, V A; Anisimov, V N; Afonin, E A; Baranov, V Y; Borzenko, V L; Kozochkin, S M; Malyuta, D D; Satov, Y A; Sebrant, A Y; Smakovski, Y B; Starostin, A N; Streltzov, A P; Petryakov, V M; Chalkin, S F

1980-03-15

57

Comparison of the carbon dioxide laser and the radiofrequency unit for feline onychectomies.  

PubMed

This study compared the collateral tissue damage and incisional bridging with granulation tissue via histopathological examination following feline onychectomy performed by radiofrequency (RF) and carbon dioxide (CO(2)) laser. Two cats were euthanized, and their digits were harvested for histopathological evaluation on days 1, 3, and 7 post-onychectomy. Each digit was evaluated for total lesion width, total necrosis width, and degree of edema, hemorrhage, and inflammation. This study found few significant differences in collateral tissue damage between RF and CO(2) laser, but more incisional bridging by granulation tissue was noted with RF for feline onychectomies. These results indicate that RF for feline onychectomy is a reasonable alternative to CO(2) laser in regard to collateral tissue damage and bridging of the incision by granulation tissue. In addition, RF is not accompanied by the strict safety considerations and initial expense of acquisition of a CO(2) laser. PMID:21041330

Burns, Sara M; Howerth, Elizabeth W; Rawlings, Clarence A; Cornell, Karen K; Radlinsky, Maryann G; Mauck, Jeffrey W

58

Measurement of Carbon Dioxide Laser-Generated Impulse and Pressure.  

National Technical Information Service (NTIS)

Measurements of impulse transferred to large metallic targets in air produced with a variable-pulse-length high-power 10.6-micro m laser beam are presented. Peak focal spot pressure measurements in Plexiglas are also presented which show that the peak pre...

J. E. Lowder L. C. Pettingill

1973-01-01

59

Treatment of common cutaneous tumors using the carbon dioxide laser  

Microsoft Academic Search

Treatment of common cutaneous neoplasms in the horse, including equine sarcoid, squamous cell carcinoma, and melanoma, can be problematic. Over the years, many techniques have been developed to minimize recurrence associated with the removal of these neoplasms. Lasers may be used to remove cutaneous tumors, offering the advantage of thermal coagulation of the surgical margins. The thermal effect may help

Scott E. Palmer

2002-01-01

60

Preliminary results from the first aircraft flight of the JPL Carbon Dioxide Laser Absorption Spectrometer  

Microsoft Academic Search

Global scale observations of carbon dioxide mixing ratios are desired to define spatial gradients of carbon dioxide, from which sources and sinks can be derived and quantified and separated from the seasonal fluctuation component. There is currently no available remote sensing instrumentation that is capable of providing the high-accuracy carbon dioxide mixing ratio measurements with the vertical and horizontal spatial

G. D. Spiers; S. Geier; R. T. Menzies

2006-01-01

61

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

2012-02-01

62

Carbon dioxide waveguide lasers with folds and tilted mirrors  

SciTech Connect

We present theoretical and experimental results for an rf-excited z-fold CO{sub 2} waveguide laser. We describe how the output power, output rotational line(s) and transverse mode(s) vary as functions of elbow mirror tilt and obtain good agreement with predictions from a multimode matrix resonator model. Observations of multilining and/or multifrequency operation are partly explained by the near equality of gain/loss ratios for two or more resonator modes.

Hill, C.A.; Jackson, P.E. (Heriot-Watt University, Physics Department, Optoelectronics Lasar Engineering, Edinburgh EH14 4AS, U.K. (GB)); Hall, D. (Royal Signals Radar Establishment, Malvern, Worcs WR14 3PS, (UK))

1990-05-20

63

Carbon dioxide laser irradiation of bacterial targets in vitro  

SciTech Connect

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

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

1987-05-01

64

Risk of acquiring human papillomavirus from the plume produced by the carbon dioxide laser in the treatment of warts  

Microsoft Academic Search

Background: The documented presence of human papillomavirus DNA in the plume after carbon dioxide laser treatment of warts has raised questions about the risk of transmission of human papillomavirus to laser surgeons.Objective: We sought to define more clearly the risks to surgeons of acquiring warts from the CO2 laser plume.Methods: A comparative study was conducted between CO2 laser surgeons and

Hugh M Gloster; Randall K Roenigk

1995-01-01

65

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

Microsoft Academic Search

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 and Nd:YAG lesions in various combinations were produced on the undersurface of dog tongues. Therapeutic time

W. J. Primrose; G. A. McDonald; M. J. OBrien; C. W. Vaughan; M. S. Strong

1987-01-01

66

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

2011-03-16

67

Hollow dielectric waveguides for carbon dioxide laser power delivery  

SciTech Connect

Present work is an investigation of the optical and mechanical properties of waveguides for the delivery of CO{sub 2} laser radiation with particular emphasis being placed on hollow waveguides. Attenuation, near field output intensity distribution, polarization maintaining ability, and power threshold of several types of hollow waveguides were measured. Theoretical approximations of the attenuation in hollow waveguides are compared with numerical solutions. The use of these waveguides in neurosurgical applications was investigated. The limits of the validity of an approximation of the characteristic equation were investigated by comparing them to a numerical solution of the equation. Approximation of the attenuation of the HE{sub 11} mode was found to be accurate for low index hollow waveguides. The optical properties of five types of round hollow waveguide were measured. The lowest attenuations of PbF{sub 2} coated aluminum and AgI coated silver waveguides were 0.6 and 0.3 dB/m respectively when straight. These waveguides were highly multi-mode and unable to preserve the polarization of the light propagating within them. The lowest attenuations of Ge coated silver and hollow sapphire waveguides were about 1 and 0.6 dB/m respectively for a 1 mm bore size. The output intensity distributions of these waveguides were close to single mode and they were capable of preserving the polarization of the propagating light. The measured losses of the sapphire are more than twice the predicted losses. The excess attenuation of the sapphire waveguides correlates exactly with losses expected from the measured roughness of the inside surface of the sapphire proving surface quality is the limiting factor in present waveguide transmission. The high power capabilities of the sapphire waveguides were found to be in excess of 1500 W. The power limit of the sapphire was determined by flaws in the material and a thermal expansion mismatch between the sapphire and the positioning mount.

Gregory, C.C.

1992-12-31

68

Carbon dioxide laser induced airway fire during larynx surgery: case report.  

PubMed

The precision intrinsic hemostatic properties of the laser have led to its wide use in modern clinical medicine especially in microscopic airway surgery. However, the intense heat generated by the high energy density of the surgical laser can convert combustible tubes into veritable torches, cause catastrophic fires, and result in severe injury to the patient. This is of particular importance when high energy is used on the continuous mode or when the endotracheal tube is repeatedly hit by the laser at the same spot. Most reported laser-induced complications result from the laser beam inadvertently falling on the areas that are not intended to be exposed. We report a case of a trans-tracheostomy tube fire occurring during carbon dioxide (CO2) laser surgery. Aluminum-tape wrapping did not prevent this complication. It was found that the ignition of a trans-tracheostomy tube was caused by the laser striking an unprotected portion of the tube during resection of granuloma of the trachea. PMID:11512372

Chou, A K; Tan, P H; Yang, L C; Sun, G C; Hsieh, S W

2001-06-01

69

Comparison of the erbium-yttrium aluminum garnet and carbon dioxide lasers for in vitro bone and cartilage ablation  

SciTech Connect

The in vitro bone- and cartilage-ablation characteristics of the solid-state erbium:yttrium aluminum garnet laser were compared to those of the carbon dioxide laser. Ablations of fresh, frozen cadaver septal cartilage and maxillary sinus bone were performed using total energies between 1 and 6 J. Specimens were studied using hematoxylin and eosin stain and digitized, computer-assisted measurements of 35-mm photographs. Erbium-yttrium aluminum garnet-ablated bone averaged 5 microns of adjacent tissue thermal injury, compared with 67 microns with carbon dioxide-ablated bone. Erbium-yttrium aluminum garnet-ablated cartilage averaged 2 microns of adjacent tissue thermal injury, compared with 21 microns with the carbon dioxide-ablated cartilage. The tissue-ablation characteristics of the erbium-yttrium aluminum garnet laser are promising for future otolaryngologic applications.

Gonzalez, C.; van de Merwe, W.P.; Smith, M.; Reinisch, L. (Uniformed Services Univ. of the Health Sciences, Bethesda, MD (USA))

1990-01-01

70

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

71

Screen for Carbon Dioxide.  

ERIC Educational Resources Information Center

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

Foster, John; And Others

1986-01-01

72

21 CFR 874.4500 - Ear, nose, and throat microsurgical carbon dioxide laser.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Ear, nose, and throat microsurgical carbon dioxide...CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Surgical Devices § 874.4500 Ear, nose, and throat microsurgical carbon...

2010-04-01

73

Investigation of the Effects of Nitrogen and Helium on the Excitation Mechanisms of a Pulsed Carbon Dioxide Laser.  

National Technical Information Service (NTIS)

An investigation of the effects of helium and nitrogen addition upon average power, peak power, pulse decay time, and pulse delay time was conducted. The excitation mechanisms for mixtures of carbon dioxide, carbon dioxide-nitrogen, carbon dioxide-helium,...

F. A. Figueroa

1969-01-01

74

Effect of a new carbon dioxide laser and fluoride on sound and demineralized enamel  

NASA Astrophysics Data System (ADS)

The present study aimed to test the hypothesis that irradiation of dental enamel by a TEA carbon dioxide laser together with fluoride, can effectively inhibit caries-like progression in sound and demineralized enamel. Blocks of human sound and demineralized dental enamel were divided into 11 treatment groups. Eighty enamel blocks were partially demineralized in a 50 percent HAP/0.1 M lactic acid/carbopol solution. Samples were treated with/without laser and/or F according to the above groups. The blocks were then submitted to 5 days of pH cycling. Microradiography was performed on 100 micrometers thin sections to determine the relative mineral loss as (Delta) Z and the percentage of caries inhibition for the laser and F treated groups. Mean (Delta) Z values for groups I-X were, respectively: 1043; 683; 614; 2294; 1803; 1708; 1547; 1791; 1656;; and 1385. The percent caries inhibition for groups II, III, V-X was respectively: 35, 41; 49; 62; 42; 53 and 76 percent. The combination of this new TEA CO2 laser and F treatment produced a significant protective effect against lesion progression.

dos Santos, Marines N.; Featherstone, John D.; Fried, Daniel

2001-04-01

75

Effect of a new carbon dioxide laser and fluoride on occlusal caries progression in dental enamel  

NASA Astrophysics Data System (ADS)

The purpose of this study was to investigate the effect of a new TEA carbon dioxide (CO2) laser (.9.6 micrometers , 5-8 microsecond(s) pulse duration) combined with fluoride (F), on the inhibition of caries-like progression in occlusal surfaces in sound and demineralized enamel. Of 120 occlusal tooth surfaces (10 per group), 90 were partially demineralized in a 50% HAP/0.1 M Lactic acid/carbopol solution (pH 5.0). Samples were treated with/without the laser (2.0 j/cm2 or 3.0 J/cm2) and/or F (as APF). Caries-like progression was tested by 5 days of pH cycling. Results were assessed by cross-sectional quantitative microradiography. The percent inhibition of caries progression with laser and/or F ranged from 87-170%. This new TEA CO2 laser produced significant protective effect against lesion progression, and in combination with fluoride treatment lesion reversal occurred.

Nobre dos Santos, Marines; Fried, Daniel; Rapozo-Hilo, Marcia L.; Featherstone, John D.

2002-06-01

76

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

NASA Astrophysics Data System (ADS)

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

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

2001-04-01

77

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

Microsoft Academic Search

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

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

1989-01-01

78

Palliative treatment of AIDS-related Kaposi's sarcoma in the upper aerodigestive tract with the carbon dioxide laser  

Microsoft Academic Search

AIDS-related Kaposi's Sarcoma (KS) in the upper aerodigestive tract, although mainly asymptomatic, sometimes causes pain, bleeding or interferes with food intake and gas exchange. In trying to overcome some of the disadvantages of currently applied treatment modalities (i.e. surgery, radiotherapy and chemotherapy), the carbon dioxide laser was used to remove this vascular tumour in selected cases. Of the 16 patients

F. W. Van Der Meulen; L. J. Schot; R. J. Hadderingh; S. Bosman; M. J. C. Van Gemert

1995-01-01

79

Recent Results From, and Future Plans for the JPL Carbon Dioxide Laser Absorption Spectrometer  

NASA Astrophysics Data System (ADS)

The Carbon Dioxide Laser Absorption Spectrometer (CO2LAS) is an aircraft based Integrated Path Differential Absorption (IPDA) Spectrometer operating in the 2 micron wavelength range that we have been developing at JPL to evaluate the measurement of the column integrated carbon dioxide concentration beneath the aircraft. The IPDA measurement technique is based on an approach first used for the measurement of ozone in the 1970s. This past year the instrument has flown on two sets of flights aboard a Twin Otter, DH-6 aircraft. The initial pair of flights, conducted in April, were flown over the El Mirage dry lake bed in the Mojave desert as an engineering checkout flight. The second set of four flights were flown over the Southern Great Plains Atmospheric Research Monitoring Site during early August and were part of a larger coordinated field experiment conducted jointly with aircraft instruments from NASA LaRC and NASA GSFC in support of the development of the ASCENDS mission as called for by the NRC Earth Science Decadal Survey. We will present a brief overview of the instrument and measurement concept, review and discuss the results of our experiments and conclude with an outline of our plans for the future.

Spiers, G. D.; Menzies, R.; Geier, S.; Phillips, M.

2009-12-01

80

Comparison of the erbium-yttrium aluminum garnet and carbon dioxide lasers for in vitro bone and cartilage ablation  

Microsoft Academic Search

The in vitro bone- and cartilage-ablation characteristics of the solid-state erbium:yttrium aluminum garnet laser were compared to those of the carbon dioxide laser. Ablations of fresh, frozen cadaver septal cartilage and maxillary sinus bone were performed using total energies between 1 and 6 J. Specimens were studied using hematoxylin and eosin stain and digitized, computer-assisted measurements of 35-mm photographs. Erbium-yttrium

Carlos Gonzalez; Willem P. Van De Merwe; Michael Smith; Lou Reinisch

1990-01-01

81

Progress on high-energy 2-micron solid state laser for NASA space-based wind and carbon dioxide measurements  

Microsoft Academic Search

Sustained research efforts at NASA Langley Research Center during last fifteen years have resulted in a significant advancement in 2-micron diode-pumped, solid-state laser transmitter for wind and carbon dioxide measurement from ground, air and space-borne platform. Solid-state 2-micron laser is a key subsystem for a coherent Doppler lidar that measures the horizontal and vertical wind velocities with high precision and

Upendra N. Singh

2011-01-01

82

Interaction of carbon dioxide laser radiation with a nanotube array in the presence of a constant electric field  

SciTech Connect

The dependence of the current density on the leading edge width of the alternating (high-frequency) field amplitude is studied at various constant (or unsteady) fields. The dependence of amplified microwaves in the two-millimeter range on a longitudinal coordinate is determined. The problem of submillimeter radiation generation in a system of parallel carbon nanotubes exposed to two-frequency carbon dioxide (CO{sub 2} laser) laser radiation in the presence of a constant (or unsteady) field is studied. The possibility of using freely oriented carbon nanotubes parallel to each other is shown.

Sadykov, N. R., E-mail: n.r.sadykov@rambler.ru [Branch of South Ural State University (Russian Federation); Scorkin, N. A. [Snezhinsk Physics and Technology Institute of the National Research Nuclear University 'MEPhI' (Russian Federation)

2012-06-15

83

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

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

84

Carbon Dioxide Reduction System.  

National Technical Information Service (NTIS)

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

H. Chandler

1964-01-01

85

Temperature VS Carbon Dioxide  

NSDL National Science Digital Library

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

86

In situ high P-T Raman spectroscopy and laser heating of carbon dioxide.  

PubMed

In situ high P-T Raman spectra of solid CO(2) up to 67 GPa and 1,660 K have been measured, using a micro-optical spectroscopy system coupled with a Nd:YLF laser heating system in diamond anvil cells. A metallic foil was employed to efficiently absorb the incoming Nd:YLF laser and heat the sample. The average sample temperature was accurately determined by detailed balance from the anti-Stokes/Stokes ratio, and was compared to the temperature of the absorber determined by fitting the thermal radiation spectrum to the Planck radiation law. The transformation temperature threshold and the transformation dynamics from the molecular phases III and II to the polymeric phase V, previously investigated only by means of temperature quench experiments, was determined at different pressures. The P-T range of the transformation, between 640 and 1,100 K in the 33-65 GPa pressure interval, was assessed to be a kinetic barrier rather than a phase boundary. These findings lead to a new interpretation of the high P-T phase diagram of carbon dioxide. Furthermore, our approach opens a new way to perform quantitative in situ Raman measurements under extremely high pressures and temperatures, providing unique information about phase relations and structural and thermodynamic properties of materials under these conditions. PMID:15281882

Santoro, Mario; Lin, Jung-fu; Mao, Ho-kwang; Hemley, Russell J

2004-08-01

87

Production of Carbon Dioxide  

NSDL National Science Digital Library

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

House, The S.

2013-05-15

88

Carbon Dioxide and Climate.  

ERIC Educational Resources Information Center

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

Brewer, Peter G.

1978-01-01

89

Carbon Dioxide Fountain  

ERIC Educational Resources Information Center

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

Kang, Seong-Joo; Ryu, Eun-Hee

2007-01-01

90

Carbon dioxide laser ablation as first-line management of in-transit cutaneous malignant melanoma metastases  

Microsoft Academic Search

IntroductionIn-transit cutaneous malignant melanoma metastases remains a difficult and distressing disease. It is a sequela to the primary\\u000a lesion represented by melanoma deposits between the site of excision and the draining lymph nodes. We present our experience\\u000a of carbon dioxide ablation of in-transit cutaneous malignant melanoma metastases and discuss the role of laser ablation as\\u000a first-line management of the disease.

Nanda Kandamany; Peter Mahaffey

2009-01-01

91

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

SciTech Connect

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.

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

1989-07-01

92

Carbon Dioxide Disposal via Carbonation  

Microsoft Academic Search

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

A. Demirbas

2007-01-01

93

Effect of combination of 1064 nm Q-switched Nd:YAG and fractional carbon dioxide lasers for treating exogenous ochronosis.  

PubMed

We describe three cases of exogenous ochronosis of the malar areas due to long-term application of skin-lightening agents for melasma, effectively treated by combination of Q-switched Nd:YAG and the fractional carbon dioxide lasers. None of these lasers has been reported to be used to effectively treat ochronosis before. The Q-switched Nd:YAG laser is capable of disintegrating dermal ochronotic fibers, thereby facilitating their phagocytosis and elimination via lymphatics. The fractional carbon dioxide laser is believed to assist transepidermal elimination of the onchronotic material. We believe successful treatment of ochronosis is possible when both mechanisms are applied. PMID:23368689

Kanechorn-Na-Ayuthaya, Pinyapat; Niumphradit, Nucha; Aunhachoke, Kobkul; Nakakes, Artit; Sittiwangkul, Rangsit; Srisuttiyakorn, Chutika

2013-02-01

94

Application of Laser-Induced Bone Therapy by Carbon Dioxide Laser Irradiation in Implant Therapy  

PubMed Central

This study evaluated the application of laser-induced bone therapy (LIBT) to reduce implant healing time in rat tibia. Twenty 10-week-old female Sprague-Dawlay rats were used. The rats received laser irradiation (laser group) or sham operation (control group) on either side of the tibia. Five days after invasion, titanium implants were inserted in proximal tibia. Five, 10, and 20 days after implant placement, tibiae were collected. After taking micro-CT and performing a torque test, the tibiae were decalcified and 8-?m-thick sections were prepared. Specimens were stained with hematoxylin and eosin. Results. Micro-CT images, removal torque values, and histomorphometric analysis data demonstrated a significantly accelerated bone formation in the laser group earlier in the healing process. Conclusion. The use of laser irradiation was effective in promoting bone formation and acquiring osseointegration of titanium implants inserted in rat tibia. LIBT may be suitable for use in implant therapy.

Naka, Takahiro; Yokose, Satoshi

2012-01-01

95

Carbon dioxide (reduction).  

National Technical Information Service (NTIS)

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

A. Fujita

2000-01-01

96

Carbon Dioxide Monitoring.  

National Technical Information Service (NTIS)

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

P. S. Biernacki J. J. Kalvinskas

1973-01-01

97

Carbon Dioxide Monitoring.  

National Technical Information Service (NTIS)

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

P. S. Biernacki J. J. Kalvinskas

1973-01-01

98

Carbon Dioxide Monitoring.  

National Technical Information Service (NTIS)

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

P. S. Biernacki J. L. Kalvinskas

1974-01-01

99

Carbon Dioxide Absorption Manifold.  

National Technical Information Service (NTIS)

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

W. E. McConnaughey

1965-01-01

100

Modeling of Carbon Monoxide Oxidation Kinetics over NASA Carbon Dioxide Laser Catalysts.  

National Technical Information Service (NTIS)

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 l...

R. K. Herz

1989-01-01

101

Carbon dioxide poisoning.  

PubMed

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

Langford, Nigel J

2005-01-01

102

Carbon dioxide foam flooding  

Microsoft Academic Search

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

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

1978-01-01

103

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

104

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

PubMed

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

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

1997-12-01

105

Aspects of carbon dioxide utilization  

Microsoft Academic Search

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

Iwao Omae

2006-01-01

106

Carbon dioxide as a feedstock.  

National Technical Information Service (NTIS)

This report is an overview on the subject of carbon dioxide as a starting material for organic syntheses of potential commercial interest and the utilization of carbon dioxide as a substrate for fuel production. It draws extensively on literature sources,...

Creutz Fujita

2000-01-01

107

ACTIVE MEDIA: Dissociation and regeneration kinetics of carbon dioxide in the active medium of sealed-off transverse RF-excited CO2 lasers  

NASA Astrophysics Data System (ADS)

An improved mathematical model describing the dissociation and regenerations kinetics of carbon dioxide in the active medium of sealed-off transverse RF-excited CO2 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 ? CO2 on the surface of alumina ceramics and Al2O3 are determined.

Vesnov, I. G.

2010-06-01

108

Carbon dioxide absorption methanol process  

Microsoft Academic Search

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

Apffel

1987-01-01

109

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

110

Carbon dioxide fixation.  

National Technical Information Service (NTIS)

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

E. Fujita

2000-01-01

111

Aqueous carbon dioxide monitor  

Microsoft Academic Search

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

1991-01-01

112

Transendoscopic and freehand use of flexible hollow fibers for carbon dioxide laser surgery in the upper airway of the horse: a preliminary report  

NASA Astrophysics Data System (ADS)

Hollow plastic fibers lined with metal and dielectric films that transmit carbon dioxide laser energy were evaluated for clinical use in upper airway surgery of the horse. These flexible waveguides were used both freehand and through the biopsy channel of an endoscope to incise, coagulate and vaporize tissues in the pharynx and larynx of 4 horses.

Palmer, Scott E.

1991-05-01

113

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

Microsoft Academic Search

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

Edward D. Kim; Kevin T. McVary

1995-01-01

114

Balancing Atmospheric Carbon Dioxide  

Microsoft Academic Search

ABSTRACT Rising carbon dioxide and global temperatures are causing increasingworldwide concern, and pressure towards an internationallaw of the atmosphere is rapidly escalating, yet widespread misconceptions about the greenhouse effect's inevitability, time scale, and causes have inhibited effective consensus and action. Observations from Antarctic ice cores, Amazonian rainforests, and Caribbean coral reefs suggest that the biological,effects,of climate,change,may,be more,severe,than,climate,models,predict. Efforts to limit

J. Goreau

115

Carbon dioxide absorption of He-Ne laser radiation at 4.2 m: characteristics of self and nitrogen broadened cases  

Microsoft Academic Search

A laser resonance absorption spectrometer is used to investigate the characteristics of both self and nitrogen collision broadened carbon dioxide in resonance with He--Ne laser radiation at 4.2 ..mu..m. The absorption coefficient in these broadening conditions has contributions from the R(28) to R(34) absorption lines of the ..nu.. CO spectrum. The Fletcher-Powell optimization method is used to reduce the raw

Craig W. Schneider; Zdenek Kucerovsky; Eric Brannen

1989-01-01

116

Carbon dioxide absorption methanol process  

Microsoft Academic Search

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

Apffel

1989-01-01

117

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

PubMed

Laser cartilage reshaping (LCR) with cryogen spray cooling is a promising modality for producing cartilage shape change while reducing cutaneous thermal injury. However, LCR in thicker tissues, such as auricular cartilage, requires higher laser power, thus increasing cooling requirements. To eliminate the risks of freeze injury characteristic of high cryogen spray pulse rates, a carbon dioxide (CO2) spray, which evaporates rapidly from the skin, has been proposed as the cooling medium. This study aims to identify parameter sets which produce clinically significant reshaping while producing minimal skin thermal injury in LCR with CO2 spray cooling in ex vivo rabbit auricular cartilage. Excised whole rabbit ears were mechanically deformed around a cylindrical jig and irradiated with a 1.45-?m wavelength diode laser (fluence 12-14J/cm(2) per pulse, four to six pulse cycles per irradiation site, five to six irradiation sites per row for four rows on each sample) with concomitant application of CO2 spray (pulse duration 33-85ms) to the skin surface. Bend angle measurements were performed before and after irradiation, and the change quantified. Surface temperature distributions were measured during irradiation/cooling. Maximum skin surface temperature ranged between 49.0 to 97.6C following four heating/cooling cycles. Significant reshaping was achieved with all laser dosimetry values with a 50-70C difference noted between controls (no cooling) and irradiated ears. Increasing cooling pulse duration yielded progressively improved gross skin protection during irradiation. CO2 spray cooling may potentially serve as an alternative to traditional cryogen spray cooling in LCR and may be the preferred cooling medium for thicker tissues. Future studies evaluating preclinical efficacy in an in vivo rabbit model are in progress. PMID:23307439

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

2013-01-10

118

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

NASA Astrophysics Data System (ADS)

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

Hawkins, Jan F.; McCauley, Charles T.

2005-04-01

119

Carbon dioxide and climate  

SciTech Connect

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

Not Available

1990-10-01

120

Carbon dioxide lasers. (Latest citations from the NTIS bibliographic database). Published Search  

SciTech Connect

The bibliography contains citations concerning theory, design, construction, and operation of CO2 lasers. Citations discuss laser pumping, modulation, reaction kinetics, gas dynamics, resonators, and tuning devices. Also discussed are laser-produced plasmas, infrared optical materials, and laser surface treatment. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

NONE

1996-04-01

121

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

122

Absorption of Carbon Dioxide on Carbonic Anhydrase Containing Substrates.  

National Technical Information Service (NTIS)

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

J. P. Allen

1968-01-01

123

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

Microsoft Academic Search

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

Jim Jih-Chyun Chang

1989-01-01

124

Fractional scanned carbon dioxide laser induces collagen remodelling in murine dermis  

NASA Astrophysics Data System (ADS)

Resurfacing using a fractional CO2 laser shows an important promise in the therapy on photoaged skin. The present study investigated that fractional CO2 laser with a special sequential scanned manner induced the collagen remodelling in murine dermis. The results showed that laser resulted in the improvement of elasticity and histology in the murine dermis, meaning laser efficacy depends on both of the collagen formation and organization. We further investigated the relations between skin elasticity and type I, and type III collagen. These data demonstrated that laser could significantly lead to the collagen remodelling in murine dermis and induce neocollagenisis as a mode of resurfacing.

Jiang, X.; Ge, H. M.; Liu, J. J.; Ren, Q. S.

2011-03-01

125

Carbon dioxide: atmospheric overload  

SciTech Connect

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

Not Available

1980-04-01

126

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

NASA Astrophysics Data System (ADS)

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

Mbanaso, Chimaobi

127

Separate and combined use of Nd:YAG and carbon dioxide lasers in oral surgery.  

PubMed

The experience obtained with 789 laser interventions used in oral surgery is summarized. In the first group, 756 patients were operated on by CO 2 laser, in the second, 17 were treated with Nd:YAG laser, and in the third, 16 were treated simultaneously with both types of lasers. Among the outpatient interventions performed under local anesthesia were 233 precancerous conditions, 491 benign tumours, and 65 other lesions. Following CO 2 laser interventions, the zone of the irreversible tissue damage did not exceed 300 mum in the instance of high energy cutting; it was almost 1 mm following Nd:YAG laser cutting, and it was 500 mum when cut by a combined laser beam. The precancerous conditions can successfully be treated by CO 2 laser, especially by evaporation. The Nd:YAG laser leaves a broad necrotic zone. The combined application, however, is highly advantageous to treat vascular lesions and markedly hemophilic structures/hemangioma, epulis, tongue resection, and so forth. In oral surgery the combined use of the CO 2 and Nd:YAG laser beams is extremely beneficial due to their excellent hemostatic effect. PMID:10149480

Gspr, L; Ksler, M; Szab, G; Bnhidy, F

1991-01-01

128

Shock Wave Acceleration of Monoenergetic Protons using a Multi-Terawatt Carbon Dioxide Laser  

NASA Astrophysics Data System (ADS)

Compact and affordable ion accelerators based on laser-produced plasmas have potential applications in many fields of science and medicine. However, the requirement of producing focusable, narrow-energy-spread, energetic beams has proved to be challenging. In this thesis, an experimental demonstration of the generation of monoenergetic ions via collisionless electrostatic shock waves driven in a laser produced plasma is presented. The physical processes behind shock wave formation, propagation, and their potential to produce monoenergetic ion beams is explored using 1D OSIRIS simulations. It is observed that a shock wave can be formed from the interpenetration of two plasmas via the expansion from a density discontinuity or an initial relative drift velocity. These processes can be instigated in the laser driven case where the laser can produce a moving sharp density spike and strong electron heating as it bores a hole through an overdense plasma. Under appropriate conditions, an electrostatic shock is formed that detaches from he laser and propagates in the plasma even after the laser is turned off. This shock can then overtake and reflect ions from the upstream plasma and accelerate them to yield a relatively narrow energy spread. A multi-terawatt CO2 laser system was developed at the UCLA Neptune Laboratory for exploring laser-driven shock wave acceleration of ions. The theory behind CO2 amplification of picosecond pulses where the bandwidth is provided by the pressure of the CO2 gas and the field of the laser pulse itself is developed. These ideas are applied for the production of 3 ps CO2 laser pulses with peak powers of up to 15 TW, currently the most powerful CO2 laser pulses ever produced. These laser pulses were used for laser-driven shock wave acceleration of protons in a hydrogen gas jet where the peak plasma density is in the range of 3--5 ncr, where ncr is the critical plasma density for 10 mum radiation. Interferometry using a picosecond 532 nm laser pulse showed that the plasma has a dynamically formed profile with a sharp (10lambda) rise to overcritical densities and a long exponential fall (30lambda). Protons accelerated from this interaction reach energies of 22 MeV, are contained within a narrow energy spread of 1%, and have geometrical emittances as low as a mm mrad. 2D OSIRIS simulations show that the laser-driven shock overtakes and reflects the protons in the slowly expanding hydrogen plasma resulting in a narrow energy spectrum. Scaling of this mechanism to higher laser powers through simulations predict the production of 200 MeV protons needed for radiotherapy by using current laser technology.

Haberberger, Daniel Joseph

129

Carbon dioxide laser effect on platelet function and surface ultrastructure in vitro  

SciTech Connect

Platelet aggregation may be an important factor in the feasibility of transcatheter laser angioplasty. The in vitro effects of increasing doses of CO/sub 2/ laser irradiation on platelet number, function, and surface ultrastructure were examined. Results indicated a progressive dose-response reduction of both platelet number and function following laser irradiation. By scanning electron microscopy the irradiated platelets showed dose-related changes in pseudopods as well as progressive damage of the cell membrane.

Eldar, M.; Gal, D.; Djaldetti, M.; Douer, D.; Rosner, E.; Katzir, A.; Neufeld, H.N.; Battler, A.

1988-01-01

130

Stalegenskaperna hos en 3 kw Koldioxidlaser (Beam Properties of a 3 kw Carbon Dioxide Laser),  

National Technical Information Service (NTIS)

In a series of experiments, the beam properties of a continuous 3 kW fast axial flow CO2 laser was surveyed. Spectrally, the laser worked steadily in the P20 transition, independent of warming up period or output power. Within the measurement accuracy, th...

S. J. Frolov

1988-01-01

131

Dielectric Coated Monolithic Hollow Metallic Waveguide for Carbon Dioxide Laser Transmission  

Microsoft Academic Search

A dielectric coated monolithic hollow metallic waveguide was developed for the transmission of CO _2 laser light, which employed a hollow silver tube as the support onto which a dense, defect free native silver halide coating was formed. This waveguide exhibited high power transmission and low loss for CO_2 and HeNe laser light when tested straight and bent. The performance

Poonam Bhardwaj

1993-01-01

132

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

Microsoft Academic Search

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

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

1990-01-01

133

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

134

Differential laser absorption spectrometry for global profiling of tropospheric carbon dioxide: selection of optimum sounding frequencies for high-precision measurements.  

PubMed

We discuss the spectroscopic requirements for a laser absorption spectrometer (LAS) approach to high-precision carbon dioxide (CO2) measurements in the troposphere. Global-scale, high-precision CO2 measurements are highly desirable in an effort to improve understanding and quantification of the CO2 sources and sinks and their impact on global climate. We present differential absorption sounding characteristics for selected LAS transmitter laser wavelengths, emphasizing the effects of atmospheric temperature profile uncertainties. Candidate wavelengths for lower-troposphere measurements are identified in the CO2 bands centered near 1.57, 1.60, and 2.06 microm. PMID:14658457

Menzies, Robert T; Tratt, David M

2003-11-20

135

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

136

The Laser Absorption Spectrometer for Carbon Dioxide Sink and Source Detection  

Microsoft Academic Search

We provide an overview of the laser absorption spectrometer development that has recently been funded under the Instrument Incubator Program. We outline the overall pro- gram including spectroscopic issues, describe the preliminary instrument design and address calibration and validation issues.

Gary D. Spiers; Robert T. Menzies; David M. Tratt; Mark Phillips

137

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

Microsoft Academic Search

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

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

1980-01-01

138

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

139

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

SciTech Connect

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

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

1980-08-15

140

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

PubMed

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

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

1980-08-15

141

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

SciTech Connect

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

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

1990-01-01

142

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.

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

2013-01-01

143

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

144

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

NASA Astrophysics Data System (ADS)

Laser-induced fluorescence (LIF) and single vibronic level (SVL) emission spectra of the ~A^2?_u - ~X^2?_g} system of 12CO_2^+ and 13CO_2^+ and the ~A^2?^+ - ~X^2? system of N_2O^+ have been observed. The cations were produced in a pulsed electric discharge jet with a precursor mixture of the corresponding neutral molecule in high pressure argon. The LIF bands of 12CO_2^+ and 13CO_2^+ were partially rotationally analyzed to obtain band origins which yielded an accurate measure of the excited state vibronic energy levels. The energy levels of both isotopologues were fitted with a Renner-Teller model that included spin-orbit coupling, Fermi resonance and anharmonic terms. SVL emission spectra were also recorded for the 13CO_2^+ ion and the ground state energy levels fitted using the same Renner-Teller model. Due to excited state predissociation, only the low lying vibrational levels have been observed in the LIF spectrum of N_2O^+. Nitrous oxide cation SVL emission spectra were collected and a complete vibronic analysis of the ~X^2? electronic state has been carried out using the Renner-Teller model. Our experimental data provide rigorous tests for future ab initio potential energy surfaces of these important cations.

Gharaibeh, Mohammed A.; Clouthier, Dennis J.

2010-06-01

145

Carbon dioxide and climate: a bibliography  

Microsoft Academic Search

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

Ringe

1980-01-01

146

Carbon dioxide and climate. A bibliography  

Microsoft Academic Search

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

Ringe

1981-01-01

147

Carbon Dioxide Information Center thesaurus  

SciTech Connect

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

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

1986-04-01

148

21 CFR 582.1240 - Carbon dioxide.  

Code of Federal Regulations, 2010 CFR

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

2009-04-01

149

Will peak oil accelerate carbon dioxide emissions?  

Microsoft Academic Search

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

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

2008-01-01

150

Dust Retardation Studies of Carbon Dioxide Sorbents.  

National Technical Information Service (NTIS)

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

F. Tepper J. V. Friel

1968-01-01

151

Reaction of Calcium Hydroxide with Carbon Dioxide.  

National Technical Information Service (NTIS)

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

F. W. Dorst

1975-01-01

152

Carbon dioxide adsorption on nanomaterials  

NASA Astrophysics Data System (ADS)

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

Galhotra, Pragati

153

Carbon Dioxide - Sources and Sinks  

NSDL National Science Digital Library

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

Universe, Windows T.

154

Aircraft monitoring of surface carbon dioxide exchange  

Microsoft Academic Search

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

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

1982-01-01

155

Aircraft Monitoring of Surface Carbon Dioxide Exchange  

Microsoft Academic Search

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

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

1982-01-01

156

Modelling Sublimation of Carbon Dioxide  

ERIC Educational Resources Information Center

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

Winkel, Brian

2012-01-01

157

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

NASA Astrophysics Data System (ADS)

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

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

1998-01-01

158

CARIOCA - monitoring carbon dioxide exchange  

SciTech Connect

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

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

1994-10-01

159

Summer Ice and Carbon Dioxide  

NASA Astrophysics Data System (ADS)

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

Kukla, G.; Gavin, J.

1981-10-01

160

Summer ice and carbon dioxide  

SciTech Connect

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

Kukla, G.; Gavin, J.

1981-10-30

161

Carbon dioxide absorption by MEA  

Microsoft Academic Search

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

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

2008-01-01

162

Lifetime of Excess Atmospheric Carbon Dioxide.  

National Technical Information Service (NTIS)

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

B. Moore B. H. Braswell

1994-01-01

163

Management practices affects soil carbon dioxide emission and carbon storage  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

164

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

SciTech Connect

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

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

1985-04-01

165

Carbon dioxide equilibria and their applications  

Microsoft Academic Search

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

1992-01-01

166

Catalyst Cartridge for Carbon Dioxide Reduction Unit.  

National Technical Information Service (NTIS)

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

R. F. Holmes

1971-01-01

167

Solubility of Carbon Dioxide in Water.  

ERIC Educational Resources Information Center

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

Bush, Pat; And Others

1992-01-01

168

Climate models should include carbon dioxide increases  

NSDL National Science Digital Library

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

Al., Narisma E.; Agu

169

Volcanic versus anthropogenic carbon dioxide  

NASA Astrophysics Data System (ADS)

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

Gerlach, Terry

2011-06-01

170

Global energy and carbon dioxide  

SciTech Connect

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

Reilly, J.; Edmonds, J.

1984-08-26

171

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

Code of Federal Regulations, 2011 CFR

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

2011-10-01

172

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

Code of Federal Regulations, 2012 CFR

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

2012-10-01

173

9 CFR 313.5 - Chemical; carbon dioxide.  

Code of Federal Regulations, 2010 CFR

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

2009-01-01

174

40 CFR 90.320 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2010 CFR

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

2009-07-01

175

9 CFR 313.5 - Chemical; carbon dioxide.  

Code of Federal Regulations, 2010 CFR

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

2010-01-01

176

40 CFR 90.320 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

177

21 CFR 868.5300 - Carbon dioxide absorbent.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

178

21 CFR 868.1400 - Carbon dioxide gas analyzer.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

179

21 CFR 868.5310 - Carbon dioxide absorber.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

180

46 CFR 108.431 - Carbon dioxide systems: General.  

Code of Federal Regulations, 2010 CFR

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

2010-10-01

181

40 CFR 90.320 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

182

40 CFR 89.322 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

183

27 CFR 26.222 - Still wines containing carbon dioxide.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

184

40 CFR 91.320 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

185

27 CFR 26.52 - Still wines containing carbon dioxide.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

186

SEQUESTERING CARBON DIOXIDE IN COALBEDS  

SciTech Connect

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

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

2001-06-15

187

CARBON DIOXIDE STORAGE IN PENNSYLVANIA PASTURES  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

188

Carbon dioxide: A substitute for phosgene  

Microsoft Academic Search

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

M. Aresta; E. Quaranta

1997-01-01

189

Carbon Dioxide Reduction and Water Electrolysis System.  

National Technical Information Service (NTIS)

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

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

1968-01-01

190

Arterialisation of transcutaneous oxygen and carbon dioxide  

Microsoft Academic Search

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

E Broadhurst; P Helms; H Vyas; G Cheriyan

1988-01-01

191

Carbon dioxide in northeastern New Mexico  

Microsoft Academic Search

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

ROY W. FOSTER; JAMES G. JENSEN

1972-01-01

192

CARBON DIOXIDE AND OUR OCEAN LEGACY  

Microsoft Academic Search

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

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

193

Energy Prices, Taxes and Carbon Dioxide Emissions  

Microsoft Academic Search

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

Peter Hoeller; Markku Wallin

1991-01-01

194

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

195

Reaction of yttrium polonides with carbon dioxide  

Microsoft Academic Search

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

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

1986-01-01

196

Sulfur dioxide absorption at DF laser wavelengths  

Microsoft Academic Search

The absorption of DF laser lines by sulfur dioxide under atmospheric conditions is measured in light of the possible application of optical methods to the detection of the atmospheric pollutant. Absorption measurements were performed for 20 DF laser wavelengths between 2792 and 2509 kaysers in a multipass absorption cell. Weak absorption is detected around a wavelength of 3.7 microns and

J. Altmann; P. Pokrowsky

1980-01-01

197

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

198

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

Microsoft Academic Search

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

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

1980-01-01

199

Experimental carbon dioxide laser brain lesions and intracranial dynamics: Part 1. Effect on intracranial pressure, systemic arterial pressure, central venous pressure, electroencephalography, and gross pathology.  

PubMed

Experimental brain lesions were created in the left parietooccipital cortex of the albino rabbit through the intact dura mater with high radiating carbon dioxide laser energy (40-watt impacts of 0.5-second duration for a total of 4 seconds on a 12.5-mm surface). Behavior, intracranial pressure (ICP), systolic arterial pressure (SAP), central venous pressure (CVP), electroencephalography (EEG), and gross pathology were studied at 2, 6, and 24 hours after the insult at a constant PaCO2 (38-42 torr). Disruption of the blood-brain barrier (Evans blue extravasation) was uniformly seen extending from the impact crater into the surrounding white matter in all groups. The ICP was elevated in sham-operated animals at 2 hours after the impact, and it remained elevated at 6 and 24 hours. The EEG revealed severe slowing with high voltage waves in the insulted left hemisphere. There was no change in mean SAP or CVP when compared to the sham-operated group. In the dexamethasone-pretreated group, there was a reduction of ICP when compared to the untreated group at 24 hours after the insult (P less than 0.005), but no changes in the gross pathology were noted. PMID:3919330

Tiznado, E; James, H E; Kemper, C

1985-01-01

200

Water and Carbon Removal from Carbon Dioxide Reduction Systems.  

National Technical Information Service (NTIS)

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

A. D. Babinsky S. J. Derezinski

1966-01-01

201

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

Microsoft Academic Search

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

Matthew B. Weinger; John E. Britain

1987-01-01

202

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

SciTech Connect

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

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

2010-02-01

203

LIFETIME OF EXCESS ATMOSPHERIC CARBON DIOXIDE  

EPA Science Inventory

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

204

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

205

Carbon Dioxide Power Plant of Medium Capacity.  

National Technical Information Service (NTIS)

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

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

1968-01-01

206

Carbon Dioxide Emission Factors for Coal  

EIA Publications

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

William Watson

1994-08-01

207

Carbon dioxide hazards in general aviation.  

PubMed

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

Gibbons, H L

1977-03-01

208

Magnesian calcite sorbent for carbon dioxide capture  

Microsoft Academic Search

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

James C. Mabry; Kanchan Mondal

2011-01-01

209

The alternative ear-piercing technique by using superpulsed carbon dioxide laser: a comparative study with spring-loaded gun  

Microsoft Academic Search

Ear piercing (EP) is increasing in popularity among teenagers. Techniques for EP should be selected carefully to prevent possible\\u000a complications. The purpose of this study is to compare the clinical outcomes of EP techniques between CO2 laser and spring-loaded gun. This is a prospective and comparative clinical trial. Under local anesthesia, EP was performed\\u000a on left ear with CO2 laser

Yu-Tuan Chang; Jiunn-Liang Wu; Jiung-Chih Chao; Cheng-Yu Lin

210

Mineralization strategies for carbon dioxide sequestration  

SciTech Connect

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

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

2003-01-01

211

The alternative ear-piercing technique by using superpulsed carbon dioxide laser: a comparative study with spring-loaded gun.  

PubMed

Ear piercing (EP) is increasing in popularity among teenagers. Techniques for EP should be selected carefully to prevent possible complications. The purpose of this study is to compare the clinical outcomes of EP techniques between CO(2) laser and spring-loaded gun. This is a prospective and comparative clinical trial. Under local anesthesia, EP was performed on left ear with CO(2) laser (20 watt/single mode) and on right ear with spring-loaded gun. With visual analog scale (VAS, 0-10) and questionnaire, post-operative pain and wound healing status were assessed immediately, 1, 2, 4 and 8 weeks after EP procedure. Fourteen subjects (14/17, 82.4%) completed the whole study. Immediately after the procedure, the level of post-operative pain (VAS) was 3.2 for CO(2) laser and 1.5 for spring-loaded gun (p < 0.05). In CO(2) laser group, pain severity decreased to 0.4, 0.1, 0, and 0, while in spring-loaded gun group, the decrease was only to 0.7, 0.6, 0.3 and 0 at 1, 2, 4, and 8 weeks, respectively. Duration of post-operative pain was 3.8 and 17.5 days for CO(2) laser and spring-loaded gun, respectively (p < 0.05). There was no major complication like infection, bleeding or hypertrophic scar. Our study suggests that CO(2) laser is a precise, simple, safe and aseptic technique for EP. It has a lower level and shorter duration of post-operative pain, when compared with spring-loaded gun. Therefore, CO(2) assisted EP is an alternative and feasible technique in our daily clinical practice. The level of evidence: 2b. PMID:21630059

Chang, Yu-Tuan; Wu, Jiunn-Liang; Chao, Jiung-Chih; Lin, Cheng-Yu

2011-06-01

212

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

Code of Federal Regulations, 2010 CFR

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

2010-10-01

213

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

Code of Federal Regulations, 2010 CFR

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

2009-10-01

214

Carbon Dioxide Laser Endoscopic Diverticulotomy for Zenkers Diverticulum: Results and Complications in a Consecutive Series of 40 Patients  

Microsoft Academic Search

Background: Numerous studies regarding CO2 laser endoscopic diverticulotomy for the treatment of Zenkers diverticulum exist. They show differences in complications, hospitalization time and postoperative treatment. Objectives: We report our experiences and work out recommendations for postoperative care. Methods: All charts of patients who were treated for Zenkers diverticulum at the University Department of Otolaryngology, Cologne, Germany, between 1983 and 2003,

Victor Helmstaedter; Alexander Engel; Karl-Bernd Huttenbrink; Orlando Guntinas-Lichius

2009-01-01

215

A Solid Electrolyte Carbon Dioxide Reduction System.  

National Technical Information Service (NTIS)

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

H. W. Chandler L. J. Howell

1969-01-01

216

A Solid Electrolyte Carbon Dioxide Reduction System.  

National Technical Information Service (NTIS)

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

H. W. Chandler L. J. Howell

1968-01-01

217

Effect of carbon dioxide on nitrification rates  

Microsoft Academic Search

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

M. Denecke; T. Liebig

2003-01-01

218

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.

219

Combined Carbon Dioxide Laser with Photodynamic Therapy for Nodular and Superficial Basal Cell Carcinoma: Almost Scarless Cure With Minimal Recurrence.  

PubMed

BACKGROUND: Basal cell carcinomas (BCCs) are often seen by general practitioners, plastic surgeons, and dermatologists in the outpatient setting. Photodynamic therapy (PDT) and CO2 laser when used as monotherapy have been successfully used to treat small BCC, with greatest success in the superficial histological subtype but have limitations compared to surgical excision due to a limited depth of penetration of PDT (2 mm absorption) limiting efficacy. We describe our experience of dual-modality treatment improving efficacy, cosmetic outcomes, and minimizing recurrence. METHODS: One hundred ten patients with a total of 177 lesions mainly on the head and neck were treated with combined therapy using an UltraPulse CO2 laser and PDT using methyl aminolevulinate (METVIX) at the same sitting, with repeat PDT 1 week later. We evaluated recurrences, cosmetic outcomes, patient satisfaction, and costs. RESULTS: The mean age of patients was 67 years. The mean follow-up period was 32.2 months, with a range of 7.7 to 68.5 months. Eighty six lesions were followed up for more than 3 years. A total of 177 lesions were diagnosed and treated. Only biopsy-proven BCCs were included in this study. Histologically, 34 (19.2%) were superficial subtype, 50 (28.2%) nodular, 9 (5.08%) infiltrative, 7 (3.95%) morpheic, 3 (1.69%) mixed, and in 74 (41.8%) diagnosis was simply BCC. All lesions responded to treatment as assessed by clinical evaluation with regular follow-up. The total recurrence-free rate was 97.1%. In 88.1% lesions, a single cycle of treatment was required; 9.03% had 2 cycles and 0.56% underwent 3 cycles. In 3 of the patients, no data were available. Recurrences were noted in 5 (2.82%) cases. All recurrences were treated successfully, all but one using repeat laser-PDT. One patient underwent surgical excision. No significant complications were encountered, although mild hypopigmentation was occasionally seen and some discomfort is experienced with PDT. CONCLUSIONS: Combined CO2 laser and PDT have equivalent cure rates to surgery for BCCs-notably of the nodular subtype-these modalities acting synergistically. This strategy provides cure often with scarless outcomes as illustrated. Laser with PDT is most appropriate for patients who value excellent cosmetic outcomes and where avoidance of an invasive procedure is an important factor. In addition, this modality comes into its own for specific groups of patients, such as those on Warfarin or those with diffuse or multiple lesions. PMID:23407256

Shokrollahi, Kayvan; Javed, Mohammed; Aeuyung, Karen; Ghattaura, Amar; Whitaker, Iain S; O'Leary, Barbara; James, William; Murison, Maxwell

2013-03-13

220

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

221

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

222

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

223

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

224

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

225

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

226

Deep sixing carbon dioxide from power plants  

NSDL National Science Digital Library

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

Jain, Atul K.; Cao, Long; Agu

227

Enhancing carbon dioxide sorption rates using hygroscopic additives  

SciTech Connect

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

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

1993-05-25

228

THE RESPIRATORY RESPONSE TO CARBON DIOXIDE  

PubMed Central

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

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

1925-01-01

229

Do Plants Really Use Carbon Dioxide?  

NSDL National Science Digital Library

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

Products, American E.

1992-01-01

230

Carbon Dioxide Extraction from Air: Is It An Option?  

SciTech Connect

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

Klaus Lackner; Hans-Joachim Ziock; Patrick Grimes

1999-02-01

231

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

232

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

233

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

234

Synthesis of Fluoropolymers in Supercritical Carbon Dioxide  

NASA Astrophysics Data System (ADS)

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

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

1992-08-01

235

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

236

Relative permeabilities of plastic films to water and carbon dioxide.  

PubMed

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

Woolley, J T

1967-05-01

237

21 CFR 868.1400 - Carbon dioxide gas analyzer.  

Code of Federal Regulations, 2010 CFR

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

2009-04-01

238

21 CFR 868.1400 - Carbon dioxide gas analyzer.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

239

40 CFR 86.1524 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

240

Carbon dioxide absorption with aqueous potassium carbonate promoted by piperazine  

Microsoft Academic Search

Many commercial processes for the removal of carbon dioxide from high-pressure gases use aqueous potassium carbonate systems promoted by secondary amines. This paper presents thermodynamic and kinetic data for aqueous potassium carbonate promoted by piperazine. Research has been performed at typical absorber conditions for the removal of CO2 from flue gas.Piperazine, used as an additive in 2030wt% potassium carbonate, was

J. Tim Cullinane; Gary T. Rochelle

2004-01-01

241

Discussion of Refrigeration Cycle Using Carbon Dioxide as Refrigerant  

NASA Astrophysics Data System (ADS)

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

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

242

Carbon dioxide emission from european estuaries  

PubMed

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

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

1998-10-16

243

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

244

Platinum catalyst for forming carbon dioxide  

SciTech Connect

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

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

1991-05-28

245

27 CFR 24.319 - Carbon dioxide record.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

246

27 CFR 24.319 - Carbon dioxide record.  

Code of Federal Regulations, 2010 CFR

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

2009-04-01

247

Leucocyte values in rats and mice following carbon dioxide euthanasia  

Microsoft Academic Search

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

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

1991-01-01

248

Randomized, Controlled Trial of Carbon Dioxide Insufflation During Colonoscopy  

Microsoft Academic Search

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

J. Church; C. Delaney

2003-01-01

249

Removal of carbon dioxide in geothermal power systems  

Microsoft Academic Search

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

Wahl

1982-01-01

250

Carbon Dioxide Enrichment Inhibits Nitrate Assimilation in Wheat and Arabidopsis  

Microsoft Academic Search

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

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

2010-01-01

251

Estimated Carbon Dioxide Emissions in 2008: United States  

Microsoft Academic Search

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

C A Smith; A J Simon; R D Belles

2011-01-01

252

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

253

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

254

9 CFR 313.5 - Chemical; carbon dioxide.  

Code of Federal Regulations, 2013 CFR

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

2013-01-01

255

CARBON DIOXIDE CONCENTRATION AI NIGHT AFFECTS TRANSLOCATION FROM SOYBEAN LEAVES  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

256

27 CFR 24.319 - Carbon dioxide record.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

257

40 CFR 91.320 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2012 CFR

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

2012-07-01

258

40 CFR 86.524-78 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

259

40 CFR 90.320 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2012 CFR

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

2012-07-01

260

40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

261

40 CFR 86.124-78 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

262

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

NASA Astrophysics Data System (ADS)

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

Winkelmann, J.

263

Spectroscopic carbon dioxide sensor for automotive applications  

Microsoft Academic Search

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

Michael Arndt; Maximilian Sauer

2004-01-01

264

Ocean Acidification: The Other Carbon Dioxide Problem  

NSDL National Science Digital Library

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

Noaa; Administration, National O.

265

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

Microsoft Academic Search

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

J. Winkelmann

2007-01-01

266

The Emission Spectrum of Carbon Dioxide  

Microsoft Academic Search

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

H. D. Smyth

1931-01-01

267

Infrared Spectrum of Carbon Dioxide Anion Radical  

Microsoft Academic Search

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

K. O. Hartman; I. C. Hisatsune

1966-01-01

268

Carbon dioxide storage potential of shales  

Microsoft Academic Search

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

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

2008-01-01

269

Catalyst Cartridge for Carbon Dioxide Reduction Unit.  

National Technical Information Service (NTIS)

A catalyst cartridge, for use in a carbon dioxide reducing apparatus in a life support system for space vehicles, is described. The catalyst cartridge includes an inner perforated metal wall, an outer perforated wall space outwardly from the inner wall, a...

R. F. Holmes

1973-01-01

270

Carbon Dioxide Reduction Aboard the Space Station.  

National Technical Information Service (NTIS)

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

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

1991-01-01

271

Carbon dioxide balneotherapy and cardiovascular disease  

Microsoft Academic Search

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

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

2010-01-01

272

Carbon dioxide balneotherapy and cardiovascular disease  

Microsoft Academic Search

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

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

2011-01-01

273

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

274

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

275

RECYCLED CARBON DIOXIDE - THE VETERAN & VERSATILE PESTICIDE  

Microsoft Academic Search

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

R. F. Ryan

276

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

NASA Astrophysics Data System (ADS)

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

Winkelmann, J.

277

Carbon dioxide emissions and global GDP  

Microsoft Academic Search

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

Michael Tucker

1995-01-01

278

Can the carbon dioxide problem be resolved  

Microsoft Academic Search

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

Lemons

1984-01-01

279

Acid sorption regeneration process using carbon dioxide  

US Patent & Trademark Office Database

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

2001-11-13

280

Carbon dioxide embolism treated with hyperbaric oxygen.  

PubMed

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

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

1989-09-01

281

Regulating Carbon Dioxide Capture and Storage  

Microsoft Academic Search

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

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

2007-01-01

282

Biogas, membranes and carbon dioxide capture  

Microsoft Academic Search

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

Eric Favre; Roda Bounaceur; Denis Roizard

2009-01-01

283

Carbon dioxide absorption in glucosamine aqueous solutions  

Microsoft Academic Search

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

D. Gmez-Daz; J. M. Navaza; B. Sanjurjo; L. Vzquez-Orgeira

2006-01-01

284

Supercritical carbon dioxide extraction of cottonseed oil  

Microsoft Academic Search

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

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

2007-01-01

285

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

286

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

287

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

288

Carbon dioxide sequestration by direct mineral carbonation with carbonic acid  

SciTech Connect

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

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

2000-01-01

289

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

Microsoft Academic Search

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

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

2001-01-01

290

Carbon dioxide capture from fossil fuel power plants using dolomite  

Microsoft Academic Search

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

Drupatie Latchman

2010-01-01

291

Global energy and carbon dioxide  

SciTech Connect

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

Reilly, J.; Edmonds, J.

1985-01-01

292

Carbon dioxide and past Antarctic temperature linked  

NASA Astrophysics Data System (ADS)

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

Balcerak, Ernie

2012-11-01

293

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

294

Hydrates of carbon dioxide and methane mixtures  

Microsoft Academic Search

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

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

1991-01-01

295

Carbon dioxide neutral, integrated biofuel facility  

Microsoft Academic Search

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

E. E. Powell; G. A. Hill

2010-01-01

296

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

297

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

298

Solubility of triacylglycerols in supercritical carbon dioxide  

Microsoft Academic Search

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

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

2007-01-01

299

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

300

Improved immobilized carbon dioxide capture sorbents  

Microsoft Academic Search

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

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

2005-01-01

301

Carbon dioxide capture with concentrated, aqueous piperazine  

Microsoft Academic Search

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

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

2010-01-01

302

Carbon dioxide absorption kinetics in potassium threonate  

Microsoft Academic Search

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

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

2008-01-01

303

Solvent selection for carbon dioxide absorption  

Microsoft Academic Search

Carbon dioxide absorption potentials of selected solvents were assessed by absorption at 40?C up to 9.5kPa CO2 partial pressure and desorption at 80?C down to 1.0kPa CO2 partial pressure and compared with monoethanolamine (MEA). Results showed that cyclic capacity of MEA in molCO2\\/molamine decreases with increase in concentration while its CO2 removal per cycle increases with concentration. Sarcosine neutralized with

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

2009-01-01

304

Solubilities of phenols in supercritical carbon dioxide  

SciTech Connect

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

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

1995-07-01

305

Single-Breath Continuous Carbon Dioxide Analysis  

Microsoft Academic Search

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

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

1955-01-01

306

Reduction of carbon dioxide on modified glassy carbon electrodes  

SciTech Connect

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

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

1999-11-01

307

Toward Carbon Dioxide Vapor-Pressure Thermometer  

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

308

Extraction of pharmaceuticals using pressurised carbon dioxide.  

PubMed

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

Dean, J R; Khundker, S

1997-04-01

309

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

310

Fluid Mechanical Modelling of Carbon Dioxide Sequestration  

NASA Astrophysics Data System (ADS)

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

Huppert, H. E.

2007-12-01

311

Bench-to-bedside review: Carbon dioxide  

PubMed Central

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

2010-01-01

312

Carbon dioxide equilibria and their applications  

SciTech Connect

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

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

1992-01-01

313

Method of immobilizing carbon dioxide from gas streams  

DOEpatents

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

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

1979-01-01

314

The fate of carbon in grasslands under carbon dioxide enrichment  

Microsoft Academic Search

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

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

1997-01-01

315

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

National Technical Information Service (NTIS)

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

M. P. Farrell

1987-01-01

316

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

317

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

Microsoft Academic Search

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

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

2003-01-01

318

Carbon dioxide: A substitute for phosgene  

SciTech Connect

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

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

1997-03-01

319

The CNG process: Acid gas removal with liquid carbon dioxide  

SciTech Connect

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

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

1987-01-01

320

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

SciTech Connect

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

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

1989-03-15

321

Carbon Dioxide 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

322

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

ERIC Educational Resources Information Center

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

Brewer, Carol A.; Beiswenger, Jane M.

1993-01-01

323

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

Microsoft Academic Search

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

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

2005-01-01

324

Carbon dioxide utilization in the chemical industry  

SciTech Connect

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

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

1996-12-31

325

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

Microsoft Academic Search

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

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

2004-01-01

326

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

Microsoft Academic Search

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

Uiram Kopcak; Rahoma Sadeg Mohamed

2005-01-01

327

Carbon dioxide exchange and early old-field succession  

Microsoft Academic Search

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

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

2006-01-01

328

Carbon Dioxide Sequestration and ECBM in the Powder River Basin  

Microsoft Academic Search

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

L. B. Colmenares; M. D. Zoback

2003-01-01

329

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

330

Carbon dioxide capture under ambient conditions using 2-chloroethylamine  

Microsoft Academic Search

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

Junhua WangXiqin; Xiqin Zhang; Yun Zhou

331

Carbon dioxide exhalation temporarily increases during electroconvulsive therapy  

Microsoft Academic Search

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

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

2006-01-01

332

Laser Cladding on Carbon-Carbon Composites.  

National Technical Information Service (NTIS)

This report describes the results of experiments on laser cladding a variety of protective coatings onto carbon-carbon substrates as oxidation- protection coatings. The work was performed using a 12-kW flattop CO2 laser and a powder delivery system to inj...

J. J. Eric R. J. Hull

2002-01-01

333

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

334

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

SciTech Connect

Vapor-liquid equilibria for carbon dioxide + cyclohexanol and carbon dioxide + cyclohexanone were measured using an apparatus based on a static-analytic method with in situ samplings. P, T, x, y measurements were made at pressures up to 22 MPa. The carbon dioxide + cyclohexanol system was studied at 433 and 473 K, and carbon dioxide + cyclohexanone, at 433 and 473 K. The results are correlated by the Redlich-Kwong-Soave and Peng and Robinson equations and several mixing rules. The best fittings are obtained with the Peng-Robinson equation of state and a two-parameter mixing rule, i.e., within 1.1% for both pressures and vapor mole fractions on the carbon dioxide + cyclohexanone system and within 1.9% for pressures and 2.9% for vapor mole fractions on the carbon dioxide + cyclohexanol system. More recent equations by Patel and Teja and Salim and Trebble show no significant advantages.

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

1997-01-01

335

Ocean Surface Carbon Dioxide Fugacity from Space  

NASA Astrophysics Data System (ADS)

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

Xie, X.; Liu, W.

2011-12-01

336

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

SciTech Connect

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

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

1981-08-01

337

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

SciTech Connect

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

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

1985-07-01

338

The fate of carbon in grasslands under carbon dioxide enrichment  

NASA Astrophysics Data System (ADS)

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

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

1997-08-01

339

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

340

Carbon dioxide pneumoperitoneum prevents mortality from sepsis  

Microsoft Academic Search

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

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

2006-01-01

341

A Vortex Contactor for Carbon Dioxide Separations  

SciTech Connect

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

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

2001-05-01

342

Monitoring urban carbon dioxide emissions on small spatial and time scales  

NSDL National Science Digital Library

A tunable diode laser absorption spectrometer was used to measure carbon dioxide mixing ratios and associated carbon isotope compositions in the atmosphere over Salt Lake City, Utah, between 15 December 2004 and 20 January 2005. A pronounced diurnal pattern was found that reflected the contribution of gasoline versus natural gas combustion to atmospheric carbon dioxide. A brief warming period was also observed. These data show that for the first time, atmospheric measurements can be used to infer patterns of energy and fuel usage on hourly to daily time scales.

Al., Pataki E.; Agu

343

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

Microsoft Academic Search

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

K. Caldeira; L. Cao

2007-01-01

344

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

345

Sulfur dioxide absorption at DF laser wavelengths  

NASA Astrophysics Data System (ADS)

The absorption of DF laser lines by sulfur dioxide under atmospheric conditions is measured in light of the possible application of optical methods to the detection of the atmospheric pollutant. Absorption measurements were performed for 20 DF laser wavelengths between 2792 and 2509 kaysers in a multipass absorption cell. Weak absorption is detected around a wavelength of 3.7 microns and is attributed to the 2 nu 3 band of SO2. The P 4(6) line at 3.9843 microns is found to be strongly absorbed by the (nu 1 + nu 3) band of SO2, with a specific absorption coefficient of 0.44 + or - 0.01/cm per atm, which indicates that strong SO2 emissions in the atmosphere can be detected optically. Measurements of the pressure dependence of the absorption coefficient of the P4(6) line reveal broadening coefficients between 1.5 and 5 MHz/Torr, depending on line strength, and a wavenumber difference of 0.0043 + or - 0.0004 kaysers from the P4(6) DF line to the center of the nearest SO2 line.

Altmann, J.; Pokrowsky, P.

1980-10-01

346

Six-fold coordinated carbon dioxide VI  

NASA Astrophysics Data System (ADS)

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

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

2007-01-01

347

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.

348

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

Code of Federal Regulations, 2010 CFR

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

2010-04-01

349

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

Code of Federal Regulations, 2010 CFR

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

2009-04-01

350

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

351

21 CFR 884.1300 - Uterotubal carbon dioxide insufflator and accessories.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

352

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

Code of Federal Regulations, 2013 CFR

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

2013-04-01

353

21 CFR 201.161 - Carbon dioxide and certain other gases.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

354

27 CFR 27.42a - Still wines containing carbon dioxide.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

355

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

356

Carbon Dioxide Cloud Formation in the Martian Polar Night  

NASA Astrophysics Data System (ADS)

Observations from the Mars Orbiter Laser Altimeter (MOLA) has revealed an assortment of clouds existing within the polar night (1). Some of these clouds appear to be composed of carbon dioxide ice particles and are associated with surface topography. A mountain wave model of cloud formation has been developed to explain these MOLA observations. Simulations have been conducted using a time dependent microphysical cloud model. Results of these simulations agree well with both the observed structure of the clouds and their estimated back-scatter cross sections. A significant result from these simulations is a substantial precipitation rate to the surface of carbon dioxide ice. For a 1 hour ``snow" storm as much as 0.75 g cm-2 of CO2 ice falls to the surface. A second type of cloud has been observed by MOLA in the southern hemisphere. These clouds are seen in the first MOLA channel and thus have a much higher extinction per kilometer than those clouds seen in the forth MOLA channel (2, 3). It is speculated here that these ``Type 1" clouds are convective towers composed of carbon dioxide ice particles. Numerical simulations of the formation of these convective towers are presented and compared to the observations. This work was supported by NASA Grant NAG5-6900. 1. Pettengill, G. H. and P. G. Ford, GRL 27, 609, 2000. 2. Muhleman, D.O. and A.B. Ivanov, MGS Mars Water and Atmosphere Workshop, 2000. 3. Pettengill, G. H. and P. G. Ford, MGS Mars Water and Atmosphere Workshop, 2000.

Colaprete, A.; Toon, O. B.

2000-10-01

357

Carbon dioxide sequestration by ex-situ mineral carbonation  

SciTech Connect

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

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

2000-01-01

358

Reaction of Carbon Dioxide with Gaseous Niobium and Niobium Oxide Clusters.  

National Technical Information Service (NTIS)

Small niobium and niobium oxide clusters (Nb(x) and Nb(x)O(y); X = 1-13, y = 1 -4) were synthesized by laser vaporization in a supersonic molecular beam system and reacted with carbon dioxide and its oxygen isotopically labeled derivative (CO*2). The reac...

L. Song A. Eychmuller R. J. St Pierre M. A. El-Sayed

1989-01-01

359

Carbon Dioxide Emissions Embodied in International Trade of Goods  

Microsoft Academic Search

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

Nadim Ahmad; Andrew Wyckoff

2003-01-01

360

A Tenuous Carbon Dioxide Atmosphere on Jupiter's Moon Callisto  

Microsoft Academic Search

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

Robert W. Carlson

1999-01-01

361

Flexible substrates as basis for photocatalytic reduction of carbon dioxide  

Microsoft Academic Search

A photocatalytic system for converting carbon dioxide into carbon monoxide was designed and constructed. The system relies on thin films of the photocatalyst prepared at low temperature using spray coating. We formulated inks based on the well-known photocatalyst titanium dioxide and characterized the performance in this setting. Glass substrates were used for model studies with an active area of 100cm2

Jacob Jensen; Mette Mikkelsen; Frederik C. Krebs

2011-01-01

362

Atmospheric carbon dioxide concentrations over the past 60 million years  

Microsoft Academic Search

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

Paul N. Pearson; Martin R. Palmer

2000-01-01

363

The Origin of Some Natural Carbon Dioxide Gases  

Microsoft Academic Search

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

Walter B. Lang

1959-01-01

364

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

Microsoft Academic Search

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

Bert W. Rust

365

Combined reactions and separations using ionic liquids and carbon dioxide  

Microsoft Academic Search

A new and general type of process for the chemical industry is presented using ionic liquids and supercritical carbon dioxide as combined reaction and separation media. In this process, the carbon dioxide pressure controls the miscibility of reactants, products, catalyst and ionic liquid, enabling fast atom-efficient reactions in a homogenous phase as well as instantaneous product recovery in a biphasic

M. C. Kroon

2006-01-01

366

Hepatic injury induced by carbon dioxide pneumoperitoneum in experimental rats  

Microsoft Academic Search

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

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

2009-01-01

367

Entrainment process of carbon dioxide in the atmospheric boundary layer  

Microsoft Academic Search

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

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

2004-01-01

368

Promising flame retardant textile in supercritical carbon dioxide  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

369

Open Nanoporous Morphologies from Polymeric Blends by Carbon Dioxide Foaming  

Microsoft Academic Search

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

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

2002-01-01

370

The Solubility of Carbon Dioxide in Water at Low Pressure  

Microsoft Academic Search

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

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

1991-01-01

371

Herbivore responses to plants grown in enriched carbon dioxide atmospheres  

Microsoft Academic Search

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

Lincoln

1990-01-01

372

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

373

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

374

A monitoring and diagnostic expert system for carbon dioxide capture  

Microsoft Academic Search

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

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

2009-01-01

375

RETROPERITONEOSCOPIC SURGERY IS NOT ASSOCIATED WITH INCREASED CARBON DIOXIDE ABSORPTION  

Microsoft Academic Search

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

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

1999-01-01

376

Ocean Acidification Consequences of Stabilization of Atmospheric Carbon Dioxide  

Microsoft Academic Search

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

L. Cao; K. Caldeira

2007-01-01

377

Irreversible climate change due to carbon dioxide emissions  

Microsoft Academic Search

The severity of damaging human-induced climate change depends not only on the magnitude of the change but also on the potential for irreversibility. This paper shows that the climate change that takes place due to increases in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop. Following cessation of emissions, removal of atmospheric carbon dioxide decreases radiative

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

2009-01-01

378

40 CFR 89.322 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2012 CFR

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

2012-07-01

379

Use of Carbon Dioxide in Enhanced Oil Recovery  

Microsoft Academic Search

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

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

1984-01-01

380

Diffuse volcanic emissions of carbon dioxide from Vulcano Island, Italy  

Microsoft Academic Search

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

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

1990-01-01

381

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

Microsoft Academic Search

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

Chris P. Tsokos

382

Annual volcanic carbon dioxide emission: An estimate from eruption chronologies  

Microsoft Academic Search

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

Steven W. Leavitt

1982-01-01

383

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

USGS Publications Warehouse

The removal of carbon dioxide gas in aquacultural systems is much more complex than for oxygen or nitrogen gas because of liquid reactions of carbon dioxide and their kinetics. Almost all published carbon dioxide removal information for aquaculture is based on the apparent removal value after the CO2(aq) + HOH ? H2CO3 reaction has reached equilibrium. The true carbon dioxide removal is larger than the apparent value, especially for high alkalinities and seawater. For low alkalinity freshwaters (<2000 ?eq/kg), the difference between the true and apparent removal is small and can be ignored for many applications. Analytical and reporting standards are recommended to improve our understanding of carbon dioxide removal.

Colt, John; Watten, Barnaby; Pfeiffer, Tim

2012-01-01

384

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

385

Photobiological hydrogen production and carbon dioxide sequestration  

NASA Astrophysics Data System (ADS)

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

Berberoglu, Halil

386

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

National Technical Information Service (NTIS)

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

J. L. Lundberg M. E. Sikorski

1983-01-01

387

Altitude controls carbon dioxide in boreal lakes  

NASA Astrophysics Data System (ADS)

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

Bhattacharya, Atreyee

2012-09-01

388

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

389

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

390

Assessing Effects of Rising Carbon Dioxide Levels on Ocean Ecosystems  

Microsoft Academic Search

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

Veronica P. Lance

2009-01-01

391

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

Microsoft Academic Search

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

1987-01-01

392

Colorimetric and refractometric measurements of carbon dioxide  

NASA Astrophysics Data System (ADS)

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

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

2011-05-01

393

A weekly cycle in atmospheric carbon dioxide  

NASA Astrophysics Data System (ADS)

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

Cerveny, Randall S.; Coakley, Kevin J.

2002-01-01

394

Thermodynamical effects during carbon dioxide release  

NASA Astrophysics Data System (ADS)

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

Singh, A. K.; Bttcher, N.; Grke, U.-J.; Kolditz, O.

2012-04-01

395

Demographic change and carbon dioxide emissions.  

PubMed

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

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

2012-07-10

396

Carbon Dioxide Sequestration in Geologic Coal Formations  

SciTech Connect

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

None

2001-09-30

397

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

Microsoft Academic Search

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

Syed Shujat Ali; Alexander Dubikaitis; Abdul Raheem Al Qattan

2002-01-01

398

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

399

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

400

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

Microsoft Academic Search

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

Ahad Ghaemi; Shahrokh Shahhosseini; Mohammad Ghanadi Maragheh

2009-01-01

401

Carbon dioxide snow storms during the polar night on Mars  

NASA Astrophysics Data System (ADS)

The Mars Orbiter Laser Altimeter detected clouds during the polar night on Mars. While these clouds are associated with topographic features, and are clearly mountain wave clouds as suggest by Pettengill and Ford [2000], we suggest that they differ greatly from terrestrial mountain wave clouds. Uplift generated from flow over the mountains may initiate the clouds on both planets. Terrestrial wave clouds are generally compact features with sharp edges. However, we find that the relatively large mass of condensate on Mars leads to diffuse clouds with snow tails that may extend many kilometers downwind 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 surface and may lead to propagating geologic features in the Martian polar regions.

Colaprete, Anthony; Toon, Owen B.

2002-07-01

402

Dispersion of organic pigments using supercritical carbon dioxide.  

PubMed

This research describes dispersion of organic pigments using supercritical fluids. With low surface tension and high diffusivity of fluids in supercritical states, aggregated particles may be effectively wetted and swelled to form the primary constituent of the dispersing solution by volume. In this paper, the conditions of temperature and pressure are used to control the density of supercritical carbon dioxide subject to PGMEA as cosolvent for dispersing organic powder in a solution. As shown from measurement with a laser scattering particle analyzer, the average diameter of phthalocyanine green 36 with the haloid structure can be significantly reduced to 93.5 nm; for aminoanthraquinone red containing and amino group (-NH(2)) and phthalocyanine blue 15:6 with symmetry benzene and inner hydrogen bond, the mean particle sizes are 178.5 and 188.7 nm, respectively, using supercritical CO(2). Additionally, the transmittance of UV light is used to confirm the dispersing performance in this study. PMID:14693141

Cheng, W T; Hsu, C W; Chih, Y W

2004-02-01

403

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

404

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

405

Herbivore responses to plants grown in enriched carbon dioxide atmospheres  

SciTech Connect

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

Lincoln, D.E.

1990-05-01

406

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

407

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

408

Moisture swing sorbent for carbon dioxide capture from ambient air.  

PubMed

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

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

2011-07-06

409

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

410

Surface plasmon resonance sensor for dissolved and gaseous carbon dioxide.  

PubMed

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

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

2012-10-18

411

High temperature carbon dioxide separation membrane  

NASA Astrophysics Data System (ADS)

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

Wade, Jennifer Lynn

412

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

413

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

SciTech Connect

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

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

2010-11-09

414

Carbon dioxide reduction at a metal phthalocyanine catalyzed carbon electrode  

SciTech Connect

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

Kapusta, S.; Hackerman, N.

1984-07-01

415

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

Microsoft Academic Search

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

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

1995-01-01

416

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

Microsoft Academic Search

Carbon dioxide capture and separation are important industrial processes that allow the use of carbon dioxide for the production of a range of chemical products and materials, and to minimize the effects of carbon dioxide emission. Porous metal-organic frameworks are promising materials to achieve such separations and to replace current technologies, which use aqueous solvents to chemically absorb carbon dioxide.

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

2012-01-01

417

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

Microsoft Academic Search

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

A. S. Eller; J. P. Sparks

2008-01-01

418

Glacial\\/interglacial variations in atmospheric carbon dioxide  

Microsoft Academic Search

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

Edward A. Boyle; Daniel M. Sigman

2000-01-01

419

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

420

The effects of carbon dioxide- and neodymium-YAG lasers on the central and peripheral nervous systems, and cerebral blood vessels.  

PubMed

The morphological reaction of brain and peripheral nerve tissue and of cerebral blood vessels to the application of two types of laser-beams is described. Lasers as cutting instruments produce smoother cut surfaces and provoke less bleeding than conventional techniques. There is almost no focal oedema. Their effects are limited to clearly determinable zones. Scar formation after laser cutting is minimised. With defocused laser-beams a photo-coagulation of tumours, for example, highly vascularised tumours or pituitary adenomas, is possible. Small arteries may be cut without bleeding. Peripheral nerves cut by use of lasers do not develop neuromas. The results of the laser technique are compared with those of conventional methods. PMID:6540297

Walter, G F; Ascher, P W; Ingolitsch, E

1984-07-01

421

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

DOEpatents

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

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

2013-01-29

422

Decorating catalytic palladium nanoparticles on carbon nanotubes in supercritical carbon dioxide  

SciTech Connect

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

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

2003-02-25

423

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

Microsoft Academic Search

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

Kyeong Taek Jung; Alexis T. Bell

2001-01-01

424

Partitioning Carbon Dioxide and Water Vapor Fluxes Using Correlation Analysis  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

425

Plants Can't Do without Carbon Dioxide.  

ERIC Educational Resources Information Center

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

Hershey, David R.

1992-01-01

426

46 CFR 76.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2011 CFR

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

2011-10-01

427

46 CFR 95.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2012 CFR

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

2012-10-01

428

46 CFR 76.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2012 CFR

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

2012-10-01

429

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

National Technical Information Service (NTIS)

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

J. Routti

1991-01-01

430

Are Carbon Dioxide Emissions Rising More Rapidly Than Expected.  

National Technical Information Service (NTIS)

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

J. Logan J. A. Leggett

2008-01-01

431

Plants Can't Do without Carbon Dioxide.  

ERIC Educational Resources Information Center

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

Hershey, David R.

1992-01-01

432

THE CHLOROPHYLL-CARBON DIOXIDE RATIO DURING PHOTOSYNTHESIS  

PubMed Central

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

McAlister, E. D.

1939-01-01

433

THE CHLOROPHYLL-CARBON DIOXIDE RATIO DURING PHOTOSYNTHESIS.  

PubMed

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

McAlister, E D

1939-05-20

434

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

Microsoft Academic Search

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

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

1990-01-01

435

Carbon dioxide sequestration by aqueous mineral carbonation of magnesium silicate minerals  

Microsoft Academic Search

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

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

2003-01-01

436

The Carbamate Reaction of Carbon Dioxide with GlycylGlycine  

Microsoft Academic Search

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

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

1966-01-01

437

Mariner 6: Origin of Mars Ionized Carbon Dioxide Ultraviolet Spectrum  

Microsoft Academic Search

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

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

1970-01-01

438

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

PubMed

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

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

1970-03-13

439

Detection of aerosolized cells during carbon dioxide laparoscopy  

Microsoft Academic Search

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

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

1998-01-01

440

Continuous supercritical carbon dioxide processing of palm oil  

Microsoft Academic Search

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

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

1996-01-01

441

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

442

Decreased hydraulic conductance in plants at elevated carbon dioxide  

Microsoft Academic Search

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

J. A. Bunce; L. H. Ziska

1998-01-01

443

Sagebrush and grasshopper responses to atmospheric carbon dioxide concentration  

Microsoft Academic Search

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

R. H. Johnson; D. E. Lincoln

1990-01-01

444

Investigation of amine amino acid salts for carbon dioxide absorption  

Microsoft Academic Search

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

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

2010-01-01

445

Annual volcanic carbon dioxide emission: An estimate from eruption chronologies  

Microsoft Academic Search

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

Steven W. Leavitt

1982-01-01

446

Interferon Alpha 2b Injections Used as an Adjuvant Therapy to Carbon Dioxide Laser Vaporization of Recalcitrant AnoGenital Condylomata Acuminata  

Microsoft Academic Search

We retrospectively analyzed our treatment of men with genital condylomata acuminata (CA) at Hennepin County Medical Center and the University of Minnesota. Between October 1985 and August 1989, 48 patients with CA were treated with laser vaporization, and 27 were treated with laser vaporization followed by a series of intralesional interferon (IFN) alpha-2b injections. The patients in the IFN group

J. Corwin Vance; Donald Davis

1990-01-01

447

Carbon dioxide sequestration by direct aqueous mineral carbonation  

SciTech Connect

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

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

2000-01-01

448

Oxygen Isotope Composition of Stratospheric Carbon Dioxide  

NASA Astrophysics Data System (ADS)

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

Rckmann, T.; Brenninkmeijer, C. A. M.; Assonov, S. S.; Lmmerzahl, P.; Krankowsky, D.; Mauersberger, K.

449

Development of Carbon Dioxide Hermitic Compressor  

NASA Astrophysics Data System (ADS)

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

Imai, Satoshi; Oda, Atsushi; Ebara, Toshiyuki

450

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

451

Carbon dioxide balneotherapy and cardiovascular disease  

NASA Astrophysics Data System (ADS)

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

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

2010-10-01

452

Rat aversion to isoflurane versus carbon dioxide.  

PubMed

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

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

2012-12-19

453

Acute carbon dioxide avoidance in Caenorhabditis elegans.  

PubMed

Carbon dioxide is produced as a by-product of cellular respiration by all aerobic organisms and thus serves for many animals as an important indicator of food, mates, and predators. However, whether free-living terrestrial nematodes such as Caenorhabditis elegans respond to CO2 was unclear. We have demonstrated that adult C. elegans display an acute avoidance response upon exposure to CO2 that is characterized by the cessation of forward movement and the rapid initiation of backward movement. This response is mediated by a cGMP signaling pathway that includes the cGMP-gated heteromeric channel TAX-2/TAX-4. CO2 avoidance is modulated by multiple signaling molecules, including the neuropeptide Y receptor NPR-1 and the calcineurin subunits TAX-6 and CNB-1. Nutritional status also modulates CO2 responsiveness via the insulin and TGFbeta signaling pathways. CO2 response is mediated by a neural circuit that includes the BAG neurons, a pair of sensory neurons of previously unknown function. TAX-2/TAX-4 function in the BAG neurons to mediate acute CO2 avoidance. Our results demonstrate that C. elegans senses and responds to CO2 using multiple signaling pathways and a neural network that includes the BAG neurons and that this response is modulated by the physiological state of the worm. PMID:18524955

Hallem, Elissa A; Sternberg, Paul W

2008-06-04

454

An optimized molecular potential for carbon dioxide.  

PubMed

An optimized molecular potential model for carbon dioxide is presented in this paper. Utilizing the established techniques of molecular-dynamics and histogram reweighting grand canonical Monte Carlo simulations, this model is demonstrated to show excellent predictability for thermodynamic, transport, and liquid structural properties in a wide temperature-pressure range with remarkable accuracies. The average deviations of this new model from experimental data for the saturated liquid densities, vapor densities, vapor pressures, and heats of vaporization are around 0.1%, 2.3%, 0.7%, and 1.9%, respectively. The calculated critical point is almost pinpointed by the new model. The experimental radial distribution functions ranging from 240.0 to 473.0 K are well reproduced as compared to neutron-diffraction measurements. The predicted self-diffusion coefficients are in good agreement with the nuclear-magnetic-resonance measurements. The previously published potential models for CO2 are also systematically evaluated, and our proposed new model is found to be superior to the previous models in general. PMID:15974754

Zhang, Zhigang; Duan, Zhenhao

2005-06-01

455

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

456

Dark fixation of carbon dioxide in an agricultural soil  

SciTech Connect

Dark fixation of carbon dioxide was monitored in an agricultural soil in northeast Georgia from December 1981 through December 1982. Carbon fixation, based on the rate of radiolabeled CO/sub 2/ incorporation, varied from 0.2 to 4.8 mg m/sup -2/ h/sup -1/. Stepwise regression analysis indicated that dark fixation was positively correlated with the rate of carbon dioxide evolution and soil temperature and was inversely correlated with irradiance. Total annual dark fixation of carbon was estimated to be 15 g m/sup -2/.

Shimmel, S.M.

1987-07-01

457

Capture of green-house carbon dioxide in Portland cement  

SciTech Connect

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

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

1993-12-31

458

Terpolymerization of ethylene, sulfur dioxide and carbon monoxide  

DOEpatents

This invention relates to a high molecular weight terpolymer of ethylene, sulfur dioxide and carbon monoxide stable to 280.degree. C. and containing as little as 36 mol % ethylene and about 41-51 mol % sulfur dioxide; and to the method of producing said terpolymer by irradiation of a liquid and gaseous mixture of ethylene, sulfur dioxide and carbon monoxide by means of Co-60 gamma rays or an electron beam, at a temperature of about 10.degree.-50.degree. C., and at a pressure of about 140 to 680 atmospheres, to initiate polymerization.

Johnson, Richard (Shirley, NY); Steinberg, Meyer (Huntington Station, NY)

1981-01-01

459

Ocean Fertilization for Sequestration of Carbon Dioxide from the Atmosphere  

NASA Astrophysics Data System (ADS)

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

Boyd, Philip W.

460

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

SciTech Connect

This project involves the use of an innovative new invention ? Particle Stabilized Emulsions (PSEs) of Carbon Dioxide-in-Water and Water-in-Carbon Dioxide for Enhanced Oil Recovery (EOR) and Permanent Sequestration of Carbon Dioxide. The EOR emulsion would be injected into a semi-depleted oil reservoir such as Dover 33 in Otsego County, Michigan. It is expected that the emulsion would dislocate the stranded heavy crude oil from the rock granule surfaces, reduce its viscosity, and increase its mobility. The advancing emulsion front should provide viscosity control which drives the reduced-viscosity oil toward the production wells. The make-up of the emulsion would be subsequently changed so it interacts with the surrounding rock minerals in order to enhance mineralization, thereby providing permanent sequestration of the injected CO{sub 2}. In Phase 1 of the project, the following tasks were accomplished: 1. Perform laboratory scale (mL/min) refinements on existing procedures for producing liquid carbon dioxide-in-water (C/W) and water-in-liquid carbon dioxide (W/C) emulsion stabilized by hydrophilic and hydrophobic fine particles, respectively, using a Kenics-type static mixer. 2. Design and cost evaluate scaled up (gal/min) C/W and W/C emulsification systems to be deployed in Phase 2 at the Otsego County semi-depleted oil field. 3. Design the modifications necessary to the present CO{sub 2} flooding system at Otsego County for emulsion injection. 4. Design monitoring and verification systems to be deployed in Phase 2 for measuring potential leakage of CO{sub 2} after emulsion injection. 5. Design production protocol to assess enhanced oil recovery with emulsion injection compared to present recovery with neat CO{sub 2} flooding. 6. Obtain Federal and State permits for emulsion injection. Initial research focused on creating particle stabilized emulsions with the smallest possible globule size so that the emulsion can penetrate even low-permeability crude oilcontaining formations or saline aquifers. The term ?globule? refers to the water or liquid carbon dioxide droplets sheathed with ultrafine particles dispersed in the continuous external medium, liquid CO{sub 2} or H{sub 2}O, respectively. The key to obtaining very small globules is the shear force acting on the two intermixing fluids, and the use of ultrafine stabilizing particles or nanoparticles. We found that using Kenics-type static mixers with a shear rate in the range of 2700 to 9800 s{sup -1} and nanoparticles between 100-300 nm produced globule sizes in the 10 to 20 ?m range. Particle stabilized emulsions with that kind of globule size should easily penetrate oil-bearing formations or saline aquifers where the pore and throat size can be on the order of 50 ?m or larger. Subsequent research focused on creating particle stabilized emulsions that are deemed particularly suitable for Permanent Sequestration of Carbon Dioxide. Based on a survey of the literature an emulsion consisting of 70% by volume of water, 30% by volume of liquid or supercritical carbon dioxide, and 2% by weight of finely pulverized limestone (CaCO{sub 3}) was selected as the most promising agent for permanent sequestration of CO{sub 2}. In order to assure penetration of the emulsion into tight formations of sandstone or other silicate rocks and carbonate or dolomite rock, it is necessary to use an emulsion consisting of the smallest possible globule size. In previous reports we described a high shear static mixer that can create such small globules. In addition to the high shear mixer, it is also necessary that the emulsion stabilizing particles be in the submicron size, preferably in the range of 0.1 to 0.2 ?m (100 to 200 nm) size. We found a commercial source of such pulverized limestone particles, in addition we purchased under this DOE Project a particle grinding apparatus that can provide particles in the desired size range. Additional work focused on attempts to generate particle stabilized emulsions with a flow through, static mixer based apparatus under a variety

Ryan, David; Golomb, Dan; Shi, Guang; Shih, Cherry; Lewczuk, Rob; Miksch, Joshua; Manmode, Rahul; Mulagapati, Srihariraju; Malepati, Chetankurmar

2011-09-30

461

Relationship between arterial carbon dioxide and end-tidal carbon dioxide when a nasal sampling port is used  

Microsoft Academic Search

End-tidal carbon dioxide (ETCO2) values obtained from awake nonintubated patients may prove to be useful in estimating a patients ventilatory status. This\\u000a study examined the relationship between arterial carbon dioxide tension (PaCO2) and ETCO2 during the preoperative period in 20 premedicated patients undergoing various surgical procedures. ETCO2 was sampled from a 16-gauge intravenous catheter pierced through one of the two

Stephen E. McNulty; John Roy; Marc Torjman; Joseph L. Seltzer

1990-01-01

462

Interaction of Surface Modified Carbon Nanotubes with Supercritical Carbon Dioxide  

NASA Astrophysics Data System (ADS)

The properties of carbon nanotube (CNT)-polymer nanocomposites are far below than those calculated, mainly due to poor dispersion or interface quality. This is particularly difficult for single walled carbon nanotubes (SWNTs) as they tend to form bundles or ropes that are difficult to exfoliate. Supercritical fluid (SCF) assisted processing is one of the methods that can be used to exfoliate/disperse CNTs along with modifiying the interface of the CNTs. Molecular dynamics simulations were performed to understand how the surface modifiers behave near SWNT surface with and without the presence of SCF molecules. It is also important to understand the diffusivity of SCF molecules between SWNT bundles and the effect of surface modifiers on diffusion. Octane and n-perflourooctane molecules were used as surface modifiers with varying tethering density and carbon dioxide (CO2) was chosen as the SCF. Results showed that the system with highest number of n-perfluorooctanes presented the highest degree of success in separating the SWNTs in the presence of CO2.

Baysal, Nihat; Unsal, Banu; Ozisik, Rahmi

2006-03-01

463

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

This report describes research conducted between April 1, 2004 and June 30, 2004 on the preparation and use of dry regenerable sorbents for removal of carbon dioxide from flue gas. Support materials and supported sorbents were prepared by spray drying. Sorbents consisting of 20 to 50% sodium carbonate on a ceramic support were prepared by spray drying in batches of approximately 300 grams. The supported sorbents exhibited greater carbon dioxide capture rates than unsupported calcined sodium bicarbonate in laboratory tests. Preliminary process design and cost estimation for a retrofit application suggested that costs of a dry regenerable sodium carbonate-based process could be lower than those of a monoethanolamine absorption system. In both cases, the greatest part of the process costs come from power plant output reductions due to parasitic consumption of steam for recovery of carbon dioxide from the capture medium.

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

2004-07-01

464

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

SciTech Connect

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

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

2012-05-22

465

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

466

Urban carbon dioxide in Portland, Oregon  

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

467

Carbon dioxide laser with an e-beam-initiated discharge produced in the working gas mixture at a pressure up to 5 atm  

SciTech Connect

A high-pressure CO{sub 2} laser with a discharge initiated by an electron beam of sub-nanosecond duration in the laser gas mixture at a pressure up to 5 atm is fabricated. For the 20-ns pulses the energy from the active volume {approx} 4 cm{sup 3} amounted to 40 mJ. The laser operation at a pulse repetition rate up to 5 Hz is demonstrated. In the gas mixture CO{sub 2}:N{sub 2}:He = 1:1:6 at a pressure 5 atm, the specific energy deposition of {approx} 0.07 J cm{sup -3} atm{sup -1} is obtained in the process of a non-self-sustained discharge with ionisation amplification.

Orlovskii, Viktor M; Alekseev, S B; Tarasenko, Viktor F [Institute of High Current Electronics, Siberian Branch, Russian Academy of Sciences, Tomsk (Russian Federation)

2011-11-30

468

Reactor design considerations in mineral sequestration of carbon dioxide  

SciTech Connect

One of the promising approaches to lowering the anthropogenic carbon dioxide levels in the atmosphere is mineral sequestration. In this approach, the carbon dioxide reacts with alkaline earth containing silicate minerals forming magnesium and/or calcium carbonates. Mineral carbonation is a multiphase reaction process involving gas, liquid and solid phases. The effective design and scale-up of the slurry reactor for mineral carbonation will require careful delineation of the rate determining step and how it changes with the scale of the reactor. The shrinking core model was used to describe the mineral carbonation reaction. Analysis of laboratory data indicates that the transformations of olivine and serpentine are controlled by chemical reaction and diffusion through an ash layer respectively. Rate parameters for olivine and serpentine carbonation are estimated from the laboratory data.

Ityokumbul, M.T.; Chander, S. (both of Pennsylvania State Univ.); O'Connor, William K.; Dahlin, David C.; Gerdemann, Stephen J.

2001-01-01

469

Calcium Carbonate Production by Coccolithophorid Algae in Long Term, Carbon Dioxide Sequestration.  

National Technical Information Service (NTIS)

Predictions of increasing levels of anthropogenic carbon dioxide (CO(sub 2)) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bi...

V. J. Fabry

2004-01-01

470

Calcium Carbonate Production by Coccolithophorid Algae in Long Term, Carbon Dioxide Sequestration.  

National Technical Information Service (NTIS)

Predictions of increasing levels of anthropogenic carbon dioxide (CO(sub 2)) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bi...

V. J. Fabry

2003-01-01

471

Supercritical Carbon Dioxide Regeneration of Activated Carbon Loaded with Contaminants from Rocky Mountain Arsenal Well Water.  

National Technical Information Service (NTIS)

The method of supercritical carbon dioxide (SCF CO2) regeneration of granular activated carbon (GAC) loaded with DIMP (diisopropyl methylphosphonate) from Rocky Mountain Arsenal Well (NO. 23-120) water was investigated. A laboratory-based adsorption/regen...

R. M. O'Brien R. P. de Filippi C. E. Smith D. G. Hager

1982-01-01

472

Removal of organic impurities from liquid carbon dioxide  

NASA Astrophysics Data System (ADS)

The use of a high velocity stream of carbon dioxide snowflakes to clean large optics is well known, and has gained widespread acceptance in the astronomical community as a telescope maintenance technique. Ultimately, however, the success of carbon dioxide snow cleaning depends on the availability of high purity carbon dioxide. The higher the purity of the carbon dioxide, the longer will be the time interval between required mirror washings. The highest grades of commercially produced liquid carbon dioxide are often not available in the more remote regions of the world - such as where major astronomical observatories are often located. Furthermore, the purity of even the highest grades of carbon dioxide are only nominal, and wide variations are known to occur from tank to tank. Occasionally, visible deposits of organic impurities are left behind during cleaning with carbon dioxide that is believed to be 99.999% pure. A zeolite molecular sieve based filtration system has proven to be very effective in removing these organic impurities. A zeolite is a complex alumino-silicate. One example has an empirical formula of Na2O(Al2O3)(SiO2)2yH2O, where y=0 to 8. The zeolites have an open crystal structure and are capable of trapping impurities like 8-methylheptadecane (an oil) and 2,6-octadine-1-ol,3,7- dimethyl-,(E)- (a fatty acid). In fact, a zeolite can trap 29.5% of its own weight in SAE 20 lubricant at 25 degree(s)C. After filtration of liquid CO2 through zeolites, the concentration of measured impurities was below the detection limit for state-of-the-art gas chromatography systems.

Zito, Richard R.

2002-09-01

473

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

474

Development of a NASICON-based amperometric carbon dioxide sensor  

Microsoft Academic Search

An alkaline silicate solgel approach has been established for the preparation of NASICON (sodium super ionic conductor). The prepared NASICON is characterized and used as the solid electrolyte and the base for an amperometric carbon dioxide sensor. An auxiliary electrolyte, a binary carbonate eutectic, is employed in this development. The fabrication and evaluation results of the sensor prototype are presented.

Yinbao Yang; Chung-Chiun Liu

2000-01-01

475

Paramagnetic properties of carbon-doped titanium dioxide  

PubMed Central

This paper reports the experimental results on paramagnetic properties of carbon-doped titanium dioxide. The electron paramagnetic resonance study of the samples has been carried out both in dark and under illumination. The nature of defects and their dynamics under illumination of carbon-doped TiO2 samples is discussed.

2012-01-01

476

CORN ROOT INFLUENCE ON AUTOMATED MEASUREMENT OF CARBON DIOXIDE CONCENTRATIONS  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

477

Assessing Carbon Dioxide Emissions from Energy Use at a University  

ERIC Educational Resources Information Center

|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

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

2009-01-01

478

Purification Characteristic Research of Carbon Dioxide in Mine Refuge Chamber  

Microsoft Academic Search

Refuge chamber is a kind of rescue equipment that protects trapped miners waiting for rescue in mine accidents. When a refuge chamber is in refuge state, carbon dioxide scrubbing is an important function of the environmental control system in chamber. In this paper, a series of experiments about the power consumption, purification efficiency, bed thickness and other factors of carbon

Jing Li; Long-zhe Jin; Sheng Wang; Shu-ci Liu; Shu Wang

2011-01-01

479

Combined carbon dioxide\\/water solid oxide electrolysis  

Microsoft Academic Search

Solid oxide electrolysis of a mixture of water and carbon dioxide has many applications in space exploration. It can be implemented in propellant production systems that use Martian resources or in closed-loop life support systems to cleanse the atmosphere of facilities in extraterrestrial bases and of cabin spacecrafts. This work endeavors to quantify the performance of combined water and carbon

Christine Schroeder Iacomini

2004-01-01

480

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

Microsoft Academic Search

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

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

2005-01-01