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Sample records for coherent co2 dial

  1. MAPM: A coherent dual CO2 laser DIAL system

    NASA Technical Reports Server (NTRS)

    Grant, W. B.; Bogan, J. R.

    1986-01-01

    The Mobile Atmospheric Pollutant Mapping System (MAPM) is a dual CO2 laser DIAL system with heterodyne detection that is being developed for large distance range resolved measurement of organic solvent vapors and aerosol clouds. The components have been chosen to allow measurements to be made to distances of 6 to 7 km in a period of 20 to 30 s. The major components of the system are listed. MAPM is being integrated into a system and will be tested with several organic solvent gases and vapors in a remotely positioned sample chamber and with a free release of ethylene. Experimental results and system performance are discussed.

  2. 2-Micron Laser Transmitter for Coherent CO2 DIAL Measurement

    NASA Technical Reports Server (NTRS)

    Singh, Upendra N.; Bai, Yingxin; Yu, Jirong

    2009-01-01

    Carbon dioxide (CO2) has been recognized as one of the most important greenhouse gases. It is essential for the study of global warming to accurately measure the CO2 concentration in the atmosphere and continuously record its variation. A high repetition rate, highly efficient, Q-switched 2-micron laser system as the transmitter of a coherent differential absorption lidar for CO2 measurement has been developed in NASA Langley Research Center. This laser system is capable of making a vertical profiling of CO2 from ground and column measurement of CO2 from air and space-borne platform. The transmitter is a master-slave laser system. The master laser operates in a single frequency, either on-line or off-line of a selected CO2 absorption line. The slave laser is a Q-switched ring-cavity Ho:YLF laser which is pumped by a Tm:fiber laser. The repetition rate can be adjusted from a few hundred Hz to 10 kHz. The injection seeding success rate is from 99.4% to 99.95%. For 1 kHz operation, the output pulse energy is 5.5mJ with the pulse length of 50 ns. The optical-to-optical efficiency is 39% when the pump power is 14.5W. A Ho:YLF laser operating in the range of 2.05 micrometers can be tuned over several characteristic lines of CO2 absorption. Experimentally, a diode pumped Ho:Tm:YLF laser has been successfully used as the transmitter of coherent differential absorption lidar for the measurement of CO2 with a repetition rate of 5 Hz and pulse energy of 75 mJ. For coherent detection, high repetition rate is required for speckle averaging to obtain highly precise measurements. However, a diode pumped Ho:Tm:YLF laser can not operate in high repetition rate due to the large heat loading and up-conversion. A Tm:fiber laser pumped Ho:YLF laser with low heat loading can operate in high repetition rate. A theoretical model has been established to simulate the performance of Tm:fiber laser pumped Ho:YLF lasers. For continuous wave (CW) operation, high pump intensity with small beam

  3. 2-Micron Laser Transmitter for Coherent CO2 DIAL Measurement

    NASA Technical Reports Server (NTRS)

    Singh, Upendra N.; Bai, Yingxin; Yu, Jirong

    2009-01-01

    Carbon dioxide (CO2) has been recognized as one of the most important greenhouse gases. It is essential for the study of global warming to accurately measure the CO2 concentration in the atmosphere and continuously record its variation. A high repetition rate, highly efficient, Q-switched 2-micron laser system as the transmitter of a coherent differential absorption lidar for CO2 measurement has been developed in NASA Langley Research Center. This laser system is capable of making a vertical profiling of CO2 from ground and column measurement of CO2 from air and space-borne platform. The transmitter is a master-slave laser system. The master laser operates in a single frequency, either on-line or off-line of a selected CO2 absorption line. The slave laser is a Q-switched ring-cavity Ho:YLF laser which is pumped by a Tm:fiber laser. The repetition rate can be adjusted from a few hundred Hz to 10 kHz. The injection seeding success rate is from 99.4% to 99.95%. For 1 kHz operation, the output pulse energy is 5.5mJ with the pulse length of 50 ns. The optical-to-optical efficiency is 39% when the pump power is 14.5W. A Ho:YLF laser operating in the range of 2.05 micrometers can be tuned over several characteristic lines of CO2 absorption. Experimentally, a diode pumped Ho:Tm:YLF laser has been successfully used as the transmitter of coherent differential absorption lidar for the measurement of CO2 with a repetition rate of 5 Hz and pulse energy of 75 mJ. For coherent detection, high repetition rate is required for speckle averaging to obtain highly precise measurements. However, a diode pumped Ho:Tm:YLF laser can not operate in high repetition rate due to the large heat loading and up-conversion. A Tm:fiber laser pumped Ho:YLF laser with low heat loading can operate in high repetition rate. A theoretical model has been established to simulate the performance of Tm:fiber laser pumped Ho:YLF lasers. For continuous wave (CW) operation, high pump intensity with small beam

  4. High Repetition Rate Pulsed 2-Micron Laser Transmitter for Coherent CO2 DIAL Measurement

    NASA Technical Reports Server (NTRS)

    Singh, Uprendra N.; Bai, Yingxin; Yu, Jirong; Petros, Mulugeta; Petzar, Paul J.; Trieu, Bo C.; Lee, Hyung

    2009-01-01

    A high repetition rate, highly efficient, Q-switched 2-micron laser system as the transmitter of a coherent differential absorption lidar for CO2 measurement has been developed at NASA Langley Research Center. Such a laser transmitter is a master-slave laser system. The master laser operates in a single frequency, either on-line or off-line of a selected CO2 absorption line. The slave laser is a Q-switched ring-cavity Ho:YLF laser which is pumped by a Tm:fiber laser. The repetition rate can be adjusted from a few hundred Hz to 10 kHz. The injection seeding success rate is from 99.4% to 99.95%. For 1 kHz operation, the output pulse energy is 5.5mJ with the pulse length of approximately 50 ns. The optical-to-optical efficiency is 39% when the pump power is 14.5W. The measured standard deviation of the laser frequency jitter is about 3 MHz.

  5. 2-μm Coherent DIAL for CO2, H2O and Wind Field Profiling in the Lower Atmosphere: Instrumentation and Results

    NASA Astrophysics Data System (ADS)

    Gibert, Fabien; Edouart, Dimitri; Cénac, Claire; Pellegrino, Jessica; Le Mounier, Florian; Dumas, Arnaud

    2016-06-01

    We report on 2-μm coherent differential absorption lidar (CDIAL) measurements of carbon dioxide (CO2), water vapour (H2O) absorption and wind field profiling in the atmospheric boundary layer. The CDIAL uses a Tm:fiber pumped, single longitudinal mode Q-switched seeded Ho:YLF laser and a fibercoupled coherent detection. The laser operates at a pulse repetition frequency of 2 kHz and emits an output energy of 10 mJ with a pulse width of 40 ns (FWHM). Experimental horizontal and vertical range-resolved measurements were made in the atmospheric boundary layer and compared to colocated in-situ sensor data.

  6. CO2 DIAL measurements of water vapor

    NASA Technical Reports Server (NTRS)

    Grant, William B.; Margolis, Jack S.; Brothers, Alan M.; Tratt, David M.

    1987-01-01

    CO2 lidars have heretofore been used to measure water vapor concentrations primarily using the 10R(20) line at 10.247 microns, which has a strong overlap with a water vapor absorption line. This paper discusses the use of that line as well as other CO2 laser lines for which the absorption coefficients are weaker. The literature on measurement of water vapor absorption coefficients using CO2 lasers is reviewed, and the results from four laboratories are shown to be generally consistent with each other after they are normalized to the same partial pressure, temperature, and ethylene absorption coefficent for the 10P(14) CO2 laser line; however, the agreement with the Air Force Geophysics Laboratory's HITRAN and FASCOD 2 spectral data tapes is not good either for the water vapor absorption lines or for the water vapor continuum. Demonstration measurements of atmospheric water vapor have been conducted using the Mobile Atmospheric Pollutant Mapping System, a dual CO2 lidar system using heterodyne detection. Results are discussed for measurements using three sets of laser line pairs covering a wide range of water vapor partial pressures.

  7. CO2 DIAL measurements of water vapor

    NASA Technical Reports Server (NTRS)

    Grant, William B.; Margolis, Jack S.; Brothers, Alan M.; Tratt, David M.

    1987-01-01

    CO2 lidars have heretofore been used to measure water vapor concentrations primarily using the 10R(20) line at 10.247 microns, which has a strong overlap with a water vapor absorption line. This paper discusses the use of that line as well as other CO2 laser lines for which the absorption coefficients are weaker. The literature on measurement of water vapor absorption coefficients using CO2 lasers is reviewed, and the results from four laboratories are shown to be generally consistent with each other after they are normalized to the same partial pressure, temperature, and ethylene absorption coefficent for the 10P(14) CO2 laser line; however, the agreement with the Air Force Geophysics Laboratory's HITRAN and FASCOD 2 spectral data tapes is not good either for the water vapor absorption lines or for the water vapor continuum. Demonstration measurements of atmospheric water vapor have been conducted using the Mobile Atmospheric Pollutant Mapping System, a dual CO2 lidar system using heterodyne detection. Results are discussed for measurements using three sets of laser line pairs covering a wide range of water vapor partial pressures.

  8. III-V Compound Detectors for CO2 DIAL Measurements

    NASA Technical Reports Server (NTRS)

    Refaat, Tamer F.; Abedin, M. Nurul; Sulima, Oleg V.; Ismail, Syed; Singh, Upendra N.

    2005-01-01

    Profiling of atmospheric carbon dioxide (CO2) is important for understanding the natural carbon cycle on Earth and its influence on global warming and climate change. Differential absorption lidar is a powerful remote sensing technique used for profiling and monitoring atmospheric constituents. Recently there has been an interest to apply this technique, at the 2 m wavelength, for investigating atmospheric CO2. This drives the need for high quality detectors at this wavelength. Although 2 m detectors are commercially available, the quest for a better detector is still on. The detector performance, regarding quantum efficiency, gain and associated noise, affects the DIAL signal-to-noise ratio and background signal, thereby influencing the instrument sensitivity and dynamic range. Detectors based on the III-V based compound materials shows a strong potential for such application. In this paper the detector requirements for a long range CO2 DIAL profiles will be discussed. These requirements were compared to newly developed III-V compound infrared detectors. The performance of ternary InGaSb pn junction devices will be presented using different substrates, as well as quaternary InGaAsSb npn structure. The performance study was based on experimental characterization of the devices dark current, spectral response, gain and noise. The final results are compared to the current state-of-the-art InGaAs technology. Npn phototransistor structure showed the best performance, regarding the internal gain and therefore the device signal-to-noise ratio. 2-micrometers detectivity as high as 3.9 x 10(exp 11) cmHz(sup 1/2)/W was obtained at a temperature of -20 C and 4 V bias voltage. This corresponds to a responsivity of 2650 A/W with about 60% quantum efficiency.

  9. Characteristics of direct detection 1.6μm CO2 DIAL with OPG transmitter

    NASA Astrophysics Data System (ADS)

    Nagasawa, C.; Shibata, Y.; Abo, M.

    2015-12-01

    In recent years, there have been significant advances in a QPM nonlinear optical frequency conversion efficienfy. The QPM condition is produced to use periodically poled ferroelectric crystals. An optical parametric oscillator (OPO), amplifier (OPA), and generator (OPG) devices are widely recognized as versatile coherent tunable spectroscopic sources. Many applications of PPLN-parametric radiation sources, such as laser remote sensing and molecular spectroscopy, require broadly tunable and narrow linewidth operation in the infrared region. We developed an optical parametric oscillator (OPO) transmitter for the first 1.6 μm CO2 DIAL. In order to improve the measurement accuracy of CO2 profiles, development of high power and wavelength stabilized laser system has been conducted. We have developed a new high-power 1.6 μm laser transmitter based on a parametric master oscillator-power amplifier (MOPA) system pumped by a LD-pumped Q-switched Nd:YAG laser which has the injection seed laser locked to the iodine absorption line. The master oscillator is the OPG transmitter and the amplifier is the OPA transmitter. Since the OPO transmitter has a cavity mirror, running the system without mode hopping requires complex control of cavity length. By contrast, the OPG transmitter has no cavity mirror, so there is no need to control cavity length. We report detail characteristics of the direct detection 1.6 μm CO2 DIAL with the OPG transmitter. Moreover, we report the technique of the simultaneously measurement temperature profiles with the CO2 concentration profiles using a CO2 absorption profile because of improvement of measurement accuracy of the CO2 concentration. This work was financially supported by the System Development Program for Advanced Measurement and Analysis of the Japan Science and Technology Agency.

  10. A new frontier in CO2 flux measurements using a highly portable DIAL laser system

    NASA Astrophysics Data System (ADS)

    Queiβer, Manuel; Granieri, Domenico; Burton, Mike

    2016-09-01

    Volcanic CO2 emissions play a key role in the geological carbon cycle, and monitoring of volcanic CO2 fluxes helps to forecast eruptions. The quantification of CO2 fluxes is challenging due to rapid dilution of magmatic CO2 in CO2-rich ambient air and the diffuse nature of many emissions, leading to large uncertainties in the global magmatic CO2 flux inventory. Here, we report measurements using a new DIAL laser remote sensing system for volcanic CO2 (CO2DIAL). Two sites in the volcanic zone of Campi Flegrei (Italy) were scanned, yielding CO2 path-amount profiles used to compute fluxes. Our results reveal a relatively high CO2 flux from Campi Flegrei, consistent with an increasing trend. Unlike previous methods, the CO2DIAL is able to measure integrated CO2 path-amounts at distances up to 2000 m using virtually any solid surface as a reflector, whilst also being highly portable. This opens a new frontier in quantification of geological and anthropogenic CO2 fluxes.

  11. A new frontier in CO2 flux measurements using a highly portable DIAL laser system.

    PubMed

    Queiβer, Manuel; Granieri, Domenico; Burton, Mike

    2016-09-22

    Volcanic CO2 emissions play a key role in the geological carbon cycle, and monitoring of volcanic CO2 fluxes helps to forecast eruptions. The quantification of CO2 fluxes is challenging due to rapid dilution of magmatic CO2 in CO2-rich ambient air and the diffuse nature of many emissions, leading to large uncertainties in the global magmatic CO2 flux inventory. Here, we report measurements using a new DIAL laser remote sensing system for volcanic CO2 (CO2DIAL). Two sites in the volcanic zone of Campi Flegrei (Italy) were scanned, yielding CO2 path-amount profiles used to compute fluxes. Our results reveal a relatively high CO2 flux from Campi Flegrei, consistent with an increasing trend. Unlike previous methods, the CO2DIAL is able to measure integrated CO2 path-amounts at distances up to 2000 m using virtually any solid surface as a reflector, whilst also being highly portable. This opens a new frontier in quantification of geological and anthropogenic CO2 fluxes.

  12. A new frontier in CO2 flux measurements using a highly portable DIAL laser system

    PubMed Central

    Queiβer, Manuel; Granieri, Domenico; Burton, Mike

    2016-01-01

    Volcanic CO2 emissions play a key role in the geological carbon cycle, and monitoring of volcanic CO2 fluxes helps to forecast eruptions. The quantification of CO2 fluxes is challenging due to rapid dilution of magmatic CO2 in CO2-rich ambient air and the diffuse nature of many emissions, leading to large uncertainties in the global magmatic CO2 flux inventory. Here, we report measurements using a new DIAL laser remote sensing system for volcanic CO2 (CO2DIAL). Two sites in the volcanic zone of Campi Flegrei (Italy) were scanned, yielding CO2 path-amount profiles used to compute fluxes. Our results reveal a relatively high CO2 flux from Campi Flegrei, consistent with an increasing trend. Unlike previous methods, the CO2DIAL is able to measure integrated CO2 path-amounts at distances up to 2000 m using virtually any solid surface as a reflector, whilst also being highly portable. This opens a new frontier in quantification of geological and anthropogenic CO2 fluxes. PMID:27652775

  13. A compact high repetition rate CO2 coherent Doppler lidar

    NASA Technical Reports Server (NTRS)

    Alejandro, S.; Frelin, R.; Dix, B.; Mcnicholl, P.

    1992-01-01

    As part of its program to develop coherent heterodyne detection lidar technology for space, airborne, and ground based applications, the Optical Environment Division of the USAF's Phillips Laboratory developed a compact coherent CO2 TEA lidar system. Although originally conceived as a high altitude balloon borne system, the lidar is presently integrated into a trailer for ground based field measurements of aerosols and wind fields. In this role, it will also serve as a testbed for signal acquisition and processing development for planned future airborne and space based solid state lidar systems. The system has also found significance in new areas of interest to the Air Force such as cloud studies and coherent Differential Absorption Lidar (DIAL) systems.

  14. A compact high repetition rate CO2 coherent Doppler lidar

    NASA Technical Reports Server (NTRS)

    Alejandro, S.; Frelin, R.; Dix, B.; Mcnicholl, P.

    1992-01-01

    As part of its program to develop coherent heterodyne detection lidar technology for space, airborne, and ground based applications, the Optical Environment Division of the USAF's Phillips Laboratory developed a compact coherent CO2 TEA lidar system. Although originally conceived as a high altitude balloon borne system, the lidar is presently integrated into a trailer for ground based field measurements of aerosols and wind fields. In this role, it will also serve as a testbed for signal acquisition and processing development for planned future airborne and space based solid state lidar systems. The system has also found significance in new areas of interest to the Air Force such as cloud studies and coherent Differential Absorption Lidar (DIAL) systems.

  15. Development and Evaluation of a High Sensitivity DIAL System for Profiling Atmospheric CO2

    NASA Technical Reports Server (NTRS)

    Ismail, Syed; Koch, Grady J.; Refaat, Tamer F.; Abedin, M. N.; Yu, Jirong; Singh, Upendra N.

    2008-01-01

    A ground-based 2-micron Differential Absorption Lidar (DIAL) CO2 profiling system for atmospheric boundary layer studies and validation of space-based CO2 sensors is being developed and tested at NASA Langley Research Center as part of the NASA Instrument Incubator Program. To capture the variability of CO2 in the lower troposphere a precision of 1-2 ppm of CO2 (less than 0.5%) with 0.5 to 1 km vertical resolution from near surface to free troposphere (4-5 km) is one of the goals of this program. In addition, a 1% (3 ppm) absolute accuracy with a 1 km resolution over 0.5 km to free troposphere (4-5 km) is also a goal of the program. This DIAL system leverages 2-micron laser technology developed under NASA's Laser Risk Reduction Program (LRRP) and other NASA programs to develop new solid-state laser technology that provides high pulse energy, tunable, wavelength-stabilized, and double-pulsed lasers that are operable over pre-selected temperature insensitive strong CO2 absorption lines suitable for profiling of lower tropospheric CO2. It also incorporates new high quantum efficiency, high gain, and relatively low noise phototransistors, and a new receiver/signal processor system to achieve high precision DIAL measurements. This presentation describes the capabilities of this system for atmospheric CO2 and aerosol profiling. Examples of atmospheric measurements in the lidar and DIAL mode will be presented.

  16. Development and Evaluation of a High Sensitivity DIAL System for Profiling Atmospheric CO2

    NASA Technical Reports Server (NTRS)

    Ismail, Syed; Koch, Grady J.; Refaat, Tamer F.; Abedin, M. N.; Yu, Jirong; Singh, Upendra N.

    2008-01-01

    A ground-based 2-micron Differential Absorption Lidar (DIAL) CO2 profiling system for atmospheric boundary layer studies and validation of space-based CO2 sensors is being developed and tested at NASA Langley Research Center as part of the NASA Instrument Incubator Program. To capture the variability of CO2 in the lower troposphere a precision of 1-2 ppm of CO2 (less than 0.5%) with 0.5 to 1 km vertical resolution from near surface to free troposphere (4-5 km) is one of the goals of this program. In addition, a 1% (3 ppm) absolute accuracy with a 1 km resolution over 0.5 km to free troposphere (4-5 km) is also a goal of the program. This DIAL system leverages 2-micron laser technology developed under NASA's Laser Risk Reduction Program (LRRP) and other NASA programs to develop new solid-state laser technology that provides high pulse energy, tunable, wavelength-stabilized, and double-pulsed lasers that are operable over pre-selected temperature insensitive strong CO2 absorption lines suitable for profiling of lower tropospheric CO2. It also incorporates new high quantum efficiency, high gain, and relatively low noise phototransistors, and a new receiver/signal processor system to achieve high precision DIAL measurements. This presentation describes the capabilities of this system for atmospheric CO2 and aerosol profiling. Examples of atmospheric measurements in the lidar and DIAL mode will be presented.

  17. Development of a Ground-Based CO2 Profiling DIAL System for Atmospheric Boundary Layer Studies

    NASA Astrophysics Data System (ADS)

    Ismail, S.; Davis, K.; Koch, G.; Abedin, M. N.; Refaat, T. F.; Singh, U. N.

    2005-12-01

    NASA Langley Research Center is developing a CO2 profiling Differential Absorption Lidar System operating in the 2.05 micron region. Data from this system can provide vertically resolved CO2 profiles over long continuous observation intervals that can alleviate a primary limit in our ability to derive regional terrestrial CO2 fluxes. Development of this system follows the development of high power, pulsed, narrow bandwidth, tunable lasers with the ability to lock onto optimum absorption lines for the measurement of CO2 profiles. The measurement precision of an existing DIAL system will be enhanced using recently acquired high quantum efficiency, high-gain, and high signal-to-noise ratio detectors and a large collection area telescope. We plan to integrate the ground-based DIAL system and evaluate and optimize its performance before it will be deployed in a field experiments. Well- calibrated, in situ infrared gas analyzers, on the ground and on aircraft, will be used to evaluate the DIAL system. We anticipate that the DIAL system will achieve 1% (3 ppm) absolute accuracy and 0.5% (1.5 ppm) precision while measuring CO2 mixing ratios with 1 km vertical resolution and 30 minute temporal resolution up to range of 4 to 5 km. This system can be used as a validation tool of the OCO (Orbiting Carbon Observatory). Data from the semi-continuous CO2 profiling DIAL system can be used in concert with in situ measurements to enable more precise derivation of regional CO2 fluxes. Examples of CO2 measurements with the existing system will be presented along with the progress made in developing the new system and its projected capability.

  18. Development of a high-speed wavelength-agile CO2 local oscillator for heterodyne DIAL measurements

    NASA Astrophysics Data System (ADS)

    Senft, Daniel C.; Pierrottet, Diego F.

    2002-06-01

    A high repetition rate, wavelength agile CO2 laser has been developed at the Air Force Research Laboratory for use as a local oscillator in a heterodyne detection receiver. Fats wavelength selection is required for measurements of airborne chemical vapors using the differential absorption lidar (DIAL) technique. Acousto-optic modulator are used to tune between different wavelengths at high speeds without the need for moving mechanical parts. Other advantages obtained by the use of acousto-optic modulators are laser output power control per wavelength and rugged packaging for field applications. The local oscillator design is described, and the results from laboratory DIAL measurements are presented. The coherent remote optical sensor system is an internal research project being conducted by the Air Force Research Laboratory Directed Energy Directorate, Active Remote Sensing Branch. The objective of the project is to develop a new long-range standoff spectral sensor that takes advantage of the enhanced performance capabilities coherent detection can provide. Emphasis of the development is on a low cost, compact, and rugged active sensor exclusively designed for heterodyne detection using the differential absorption lidar technique. State of the art technologies in waveguide laser construction and acousto- optics make feasible the next generation of lasers capable of supporting coherent lidar system requirements. Issues addressed as part of the development include optoelectronic engineering of a low cost rugged system, and fast data throughput for real time chemical concentration measurements. All hardware used in this sensor are off-the- shelf items, so only minor hardware modifications were required for the system as it stands. This paper describes a high-speed heterodyne detection CO2 DIAL system that employs a wavelength agile, acousto-optically tuned local oscillator in the receiver. Sample experimental data collected in a controlled environment are presented as

  19. New advances in Dial-Lidar-based remote sensing of the volcanic CO2 flux

    NASA Astrophysics Data System (ADS)

    Aiuppa, Alessandro; Fiorani, Luca; Santoro, Simone; Parracino, Stefano; D'Aleo, Roberto; Liuzzo, Marco; Maio, Giovanni; Nuvoli, Marcello

    2017-02-01

    We report here on the results of a proof-of-concept study aimed at remotely sensing the volcanic CO2 flux using a Differential Adsorption lidar (DIAL-lidar). The observations we report on were conducted on June 2014 on Stromboli volcano, where our lidar (LIght Detection And Ranging) was used to scan the volcanic plume from 3 km distance from the summit vents. The obtained results prove that a remotely operating lidar can resolve a volcanic CO2 signal of a few tens of ppm (in excess to background air) over km-long optical paths. We combine these results with independent estimates of plume transport speed (from processing of UV Camera images) to derive volcanic CO2 flux time-series of ≈16-33 minutes temporal resolution. Our lidar-based CO2 fluxes range from 1.8±0.5 to 32.1±8.0 kg/s, and constrain the daily averaged CO2 emissions from Stromboli at 8.3±2.1 to 18.1±4.5 kg/s (or 718-1565 tons/day). These inferred fluxes fall within the range of earlier observations at Stromboli. They also agree well with contemporaneous CO2 flux determinations (8.4-20.1 kg/s) obtained using a standard approach that combines Multi-GAS-based in-plume readings of the CO2/SO2 ratio (≈ 8) with UV-camera sensed SO2 fluxes (1.5-3.4 kg/s). We conclude that DIAL-lidars offer new prospects for safer (remote) instrumental observations of the volcanic CO2 flux.

  20. Development and testing of a long-range airborne CO2 DIAL chemical detection system

    NASA Astrophysics Data System (ADS)

    Higdon, N. Scott; Senft, Daniel C.; Fox, Marsha J.; Hamilton, Carla M.; Kelly, Brian T.; Dowling, James A.; Pierrottet, Diego F.; Dean, David R.; Richter, Dale A.; Bousek, Ronald R.

    1998-11-01

    The Air Force Research Laboratory has developed and tested an airborne CO2 differential absorption lidar system for the remote detection of chemicals. The Laser Airborne Remote Sensing DIAL system uses topographic backscatter to provide a long-range measurement of the column-content absorption of chemical plumes in the path of the laser beam. A high-power CO2 laser, capable of operation on multiple isotopes, and a Mersenne telescope constitute the major transceiver components. In addition to the laser, telescope, and transceiver optics, several onboard diagnostic instruments were mounted on the flight bench to monitor and optimize the system performance during airborne operation. The flight bench, electronics racks, and data acquisition and experiment control stations were designed to be integrated onto the AFRL C-135E research aircraft, and to utilize the existing pointing and tracking system on the aircraft.

  1. InGaAsSb Detectors' Characterization for 2-Micron CO2 Lidar/DIAL Applications

    NASA Technical Reports Server (NTRS)

    Refaat, Tamer F.; Abedin, M. Nurul; Koch, Grady J.; Singh, Upendra N.

    2003-01-01

    Recent interest in monitoring atmospheric CO2 focuses attention on infrared remote sensing using the 2-micron lidar/differential absorption lidar (DIAL) technique. Quantum detectors are critical components in this technique, and many research efforts concentrate on developing such devices for the 2-micron wavelength. Characterization results of InGaAsSb quantum detectors for the 2-micron wavelength range are presented, including experimental setup and procedure. Detectors are prototype devices manufactured by using separate absorption and multiplication (SAM) structures. Characterization experiments include V-I measurements, spectral response and its variation with bias voltage and temperature, noise measurements, noise-equivalent-power (NEP) and detectivity calculations, and signal-to-noise ratio (SNR) estimation. A slight increase in the output signal occurred with increased bias voltage and was associated with a noise level increase. Cooling down the detectors reduces noise and shifts the cutoff wavelength to shorter values. Further improvement in the design and manufacturing process, by increasing the device gain and lowering its noise level, is necessary to meet the required CO2 lidar/DIAL specifications.

  2. On-line wavelength calibration of pulsed laser for CO2 DIAL sensing

    NASA Astrophysics Data System (ADS)

    Han, Ge; Gong, Wei; Lin, Hong; Ma, Xin; Xiang, Chengzhi

    2014-12-01

    Accurate on-line wavelength calibration is a crucial procedure for sensing atmospheric CO2 using the DIAL technique. Drastic fluctuations in the intensity of a pulsed laser pose a great challenge for accurate on-line wavelength determination and stabilization, resulting in CO2 retrievals lacking the desired accuracy for global climate change and carbon cycle research. To tackle this problem, a two-stage wavelength calibration method based on Voigt fitting was proposed in this work. Simulation analysis demonstrated that the proposed method is superior to the conventional method and provides wavelength calibration results with an accuracy of 0.1 pm when the noise level does not exceed than 5 %. This conclusion was confirmed through experiments with real signals. Furthermore, simulation analysis revealed that the proposed method could yield results with an accuracy of 0.1 pm by increasing the number of sample points, even for signals with noise levels of up to 20 %. This is a promising feature that could facilitate the development of DIAL systems without gas cells.

  3. Development of Ground-Based DIAL Techniques for High Accurate Measurements of CO2 Concentration Profiles in the Atmosphere

    NASA Astrophysics Data System (ADS)

    Nagasawa, C.; Abo, M.; Shibata, Y.; Nagai, T.; Nakazato, M.; Sakai, T.; Tsukamoto, M.; Sakaizawa, D.

    2009-12-01

    High-accurate vertical carbon dioxide (CO2) profiles are highly desirable in the inverse method to improve quantification and understanding of the global sink and source of CO2, and also global climate change. We have developed a ground based 1.6μm differential absorption lidar (DIAL) to achieve high accurate measurements of vertical CO2 profiles in the atmosphere. The DIAL system is constructed from the optical parametric oscillation(OPO) transmitter and the direct detection receiving system that included a near-infrared photomultiplier tube operating at photon counting mode (Fig.1). The primitive DIAL measurement was achieved successfully the vertical CO2 profile up to 7 km altitude with an error less than 1.0 % by integration time of 50 minutes and vertical resolution of 150m. We develop the next generation 1.6 μm DIAL that can measure simultaneously the vertical CO2 concentration, temperature and pressure profiles in the atmosphere. The characteristics of the 1.6 μm DIALs of the primitive and next generations are shown in Table 1. As the spectra of absorption lines of any molecules are influenced basically by the temperature and pressure in the atmosphere, it is important to measure them simultaneously so that the better accuracy of the DIAL measurement may be realized. Moreover, the value of the retrieved CO2 concentration will be improved remarkably by processing the iteration assignment of CO2 concentration, temperature and pressure which measured by DIAL techniques. This work was financially supported by the Japan EOS Promotion Program by the MEXT Japan and System Development Program for Advanced Measurement and Analysis by the JST. Reference D. Sakaisawa et al., Development of a 1.6μm differential absorption lidar with a quasi-phase-matching optical parametric oscillator and photon-counting detector for the vertical CO2 profile, Applied Optics, Vol.48, No.4, pp.748-757, 2009. Fig. 1 Experimental setup of the 1.6 μm CO2 DIAL. Comparison of primitive

  4. Measurement of Lower-Atmospheric CO2 Concentration Distribution Using a Compact 1.6 μm DIAL

    NASA Astrophysics Data System (ADS)

    Shibata, Yasukuni; Nagasawa, Chikao; Abo, Makoto

    2016-06-01

    Knowledge of present carbon sources and sinks including their spatial distribution and their variation in time is one of the essential information for predicting future CO2 atmospheric concentration levels. The differential absorption lidar (DIAL) is expected to measure atmospheric CO2 profiles in the atmospheric boundary layer and lower troposphere from a ground platform. We have succeeded to develop a compact 1.6 μm DIAL system for measuring CO2 concentration profiles in the lower atmosphere. This 1.6 μm DIAL system consists of the optical parametric generator (OPG) transmitter that excited by the LD pumped Nd:YAG laser with high repetition rate and the receiving optics that included the near-infrared photomultiplier tube operating at the analog mode and a 25 cm telescope. CO2 concentration profiles were obtained up to 2.5 km altitude.

  5. DIAL with heterodyne detection including speckle noise: Aircraft/shuttle measurements of O3, H2O, and NH3 with pulsed tunable CO2 lasers

    NASA Technical Reports Server (NTRS)

    Brockman, P.; Hess, R. V.; Staton, L. D.; Bair, C. H.

    1980-01-01

    Atmospheric trace constituent measurements with higher vertical resolution than attainable with passive radiometers are discussed. Infrared differential absorption lidar (DIAL), which depends on Mie scattering from aerosols, has special advantages for tropospheric and lower stratospheric applications and has great potential importance for measurements from shuttle and aircraft. Differential absorption lidar data reduction involves comparing large amplitude signals which have small differences. The accuracy of the trace constituent concentration inferred from DIAL measurements depends strongly on the errors in determining the amplitude of the signals. Thus, the commonly used SNR expression (signal divided by noise in the absence of signal) is not adequate to describe DIAL measurement accuracy and must be replaced by an expression which includes the random coherent (speckle) noise within the signal. A comprehensive DIAL computer algorithm is modified to include heterodyne detection and speckle noise. Examples for monitoring vertical distributions of O3, H2O, and NH3 using a ground-, aircraft-, or shuttle-based pulsed tunable CO2 laser DIAL system are given.

  6. Development of a Coherent Differential Absorption Lidar for Range Resolved Atmospheric CO2 Measurements

    NASA Technical Reports Server (NTRS)

    Yu, Jirong; Petros, Mulgueta; Chen, Songsheng; Bai, Yingxin; Petzar, Paul J.; Trieu, Bo. C.; Koch, Grady J.; Beyon, Jeffery J.; Singh, Upendra N.

    2010-01-01

    A pulsed, 2-m coherent Differential Absorption Lidar (DIAL) / Integrated Path Differential Absorption (IPDA) transceiver, developed under the Laser Risk Reduction Program (LRRP) at NASA, is integrated into a fully functional lidar instrument. This instrument will measure atmospheric CO2 profiles (by DIAL) initially from a ground platform, and then be prepared for aircraft installation to measure the atmospheric CO2 column densities in the atmospheric boundary layer (ABL) and lower troposphere. The airborne prototype CO2 lidar can measure atmospheric CO2 column density in a range bin of 1km with better than 1.5% precision at horizontal resolution of less than 50km. It can provide the image of the pooling of CO2 in lowlying areas and performs nighttime mass balance measurements at landscape scale. This sensor is unique in its capability to study the vertical ABL-free troposphere exchange of CO2 directly. It will allow the investigators to pursue subsequent in science-driven deployments, and provides a unique tool for Active Sensing of CO2 Emissions over Night, Days, and Seasons (ASCENDS) validation that was strongly advocated in the recent ASCENDS Workshop.

  7. A Direct Detection 1.6μm DIAL with Three Wavelengths for Measurements of Vertical CO2 Concentration and Temperature Profiles in the Atmosphere

    NASA Astrophysics Data System (ADS)

    Nagasawa, C.; Abo, M.; Shibata, Y.; Nagai, T.; Tsukamoto, M.

    2012-12-01

    We report the new 1.6 μm DIAL system that can measure the temperature profiles with the CO2 concentration profiles in the atmosphere because of improvement of measurement accuracy of the CO2 density and mixing ratio (ppm). We have developed a direct detection 1.6 μm differential absorption lidar (DIAL) technique to perform range-resolved measurements of vertical CO2 concentration profiles in the atmosphere [Sakaizawa et al. 2009]. Our 1.6 μm DIAL system consists of the Optical Parametric Generator (OPG) transmitter that excited by the LD pumped Nd:YAG laser with high repetition rate (500 Hz) and the receiving optics that included the near-infrared photomultiplier tube with high quantum efficiency operating at the photon counting mode and the telescope with larger aperture than that of the coherent detection method. Laser beams of three wavelengths around a CO2 absorption line is transmitted alternately to the atmosphere for measurements of CO2 concentration and temperature profiles. Moreover, a few retrieval algorithms of CO2-DIAL are also performed for improvement of measurement accuracy. The accurate vertical CO2 profiles in the troposphere are highly desirable in the inverse techniques to improve quantification and understanding of the global budget of CO2 and also global climate changes [Stephens et al. 2007]. In comparison with the ground-based monitoring network, CO2 measurements for vertical profiles in the troposphere have been limited to campaign-style aircraft and commercial airline observations with the limited spatial and temporal coverage. This work was financially supported by the System Development Program for Advanced Measurement and Analysis of the Japan Science and Technology Agency. References Sakaizawa, D., C. Nagasawa, T. Nagai, M. Abo, Y. Shibata, H. Nagai, M. Nakazato, and T. Sakai, Development of a 1.6μm differential absorption lidar with a quasi-phase-matching optical parametric oscillator and photon-counting detector for the vertical

  8. Ground test results and analysis advancements for the AFRL airborne CO2 DIAL system

    NASA Astrophysics Data System (ADS)

    Senft, Daniel C.; Fox, Marsha J.; Hamilton, Carla M.; Richter, Dale A.; Higdon, N. S.; Kelly, Brian T.; Babnick, Robert D.; Pierrottet, Diego F.

    1999-10-01

    The Air Force Research Laboratory (AFRL) Active Remote Sensing Branch has developed the Laser Airborne Remote Sensing (LARS) system for chemical detection using the differential absorption lidar technique. The system is based on a high-power CO2 laser which can use either the standard 12C16O2 or the 13C16O2 carbon dioxide isotopes as the lasing medium, and has output energies of up to 5 J on the stronger laser transitions. The lidar system is mounted on a flight-qualified optical breadboard designed for installation into the AFRL Argus C- 135E optical testbed aircraft. The Phase I ground tests were conducted at Kirtland AFB in 1997, prior to the LARS flight tests performed in September 1997 at Kirtland AFB and the Idaho National Engineering and Environmental Laboratory. The Phase II ground tests were conducted in 1998 to determine the optimum performance of the LARS systems, after the incorporation of modifications and improvements suggested by the flight test results. This paper will present some of the chemical detection and radiometric results obtained during the Phase II ground tests. Following the presentation of the direct detection results, a summary of current work on a heterodyne DIAL system is given.

  9. ACTIVITIES CONDUCTED AT IPSL AND ESA TO SUPPORT A CO2 DIAL SPACE MISSION FOR CLIMATE CHANGE ISSUE

    NASA Astrophysics Data System (ADS)

    Flamant, P. H.; Gibert, F.; Édouart, D.; Cuesta, J.; Bruneau, D.

    2009-12-01

    Since 2002, the Institut-Pierre-Simon-Laplace (IPSL) is involved in several projects addressing CO2 monitoring by Dial lidar for environmental science and space borne applications. The activity started with the development of a 2-µm CO2 heterodyne DiAL project. The first instrumental activity gave rise to two new programs to develop a transportable CO2 DiAL in a container using fiber technologies and then an airborne system. In 2006, “A-SCOPE” a proposal aiming at a space borne Integrated Path CO2 DiAL mission has been submitted to the European Space Agency (ESA) in response to a Call for Ideas in the framework of the Earth Explorer Mission program. The IPDA technique makes use of signal returns from the surface. Accordingly canopy height and surface information will be provided as spin-off products in addition to dry CO2 mixing ratio as the main products. A-SCOPE has been selected with 5 other missions for phase “0” study and preliminary feasibility assessments by 2 European industrial consortia. A Mission Assessment Group has been formed by ESA to support the mission definition and write a Report for Assessment (ESA SP-1313/1). A-SCOPE and the 5 other potential missions have been presented and discussed during the Users Consultation Meeting (UMC) in Lisbon, Portugal, 20-21 January 2009. The A-SCOPE Report for Assessment, the discussion during UMC and on-going activities will be presented at the conference to support a future mission like “A-SCOPE”.

  10. Investigating the effect of aerosol droplets in a volcanic plume for increasing sensitivity of a CO2 DIAL measurement

    NASA Astrophysics Data System (ADS)

    Queißer, M.; Burton, M.; Fiorani, L.; Saleh, W. R.

    2013-10-01

    Volcanic CO2 emissions are an important element of the carbon cycle, but they are very poorly constrained. This is due to the great challenge posed by the quantification of a potentially small volcanic CO2 signal against a strong background atmospheric signal. There is therefore great interest in developing and applying novel, sensitive techniques which may be able to remotely quantify trace volcanic CO2 amounts. Differential Absorption LIDAR (DIAL) is one such technique which may allow remote monitoring of volcanic CO2 emissions. CO2 is typically the second most abundant volcanic gas, the first being H2O, which can condense upon emission, producing dense aerosol clouds. These aerosols will strongly affect absorption and backscattering of the probing DIAL light. We employ Mie's equations to calculate their scattering and extinction properties. We consider two extreme droplet number densities. We find that both backscattering and extinction coefficient increase by more than 4 orders of magnitude with respect to the case without any liquid water in the volcanic plume. The fraction of light scattered back to the DIAL instrument in a single scattering event increases by a factor of 100 relative to the clear atmosphere. For the LIDAR signal this implies a relative increase in backscattered light by up to 4 and 5 orders of magnitude for the low density and high density cloud scenario, respectively. The results suggest that a condensed water cloud within the plume region may act as a strong reflector, and greatly enhances the signal strength and hence sensitivity of a DIAL system compared with backscattering in the clear atmosphere.

  11. Atmospheric correlation time measurements using coherent CO2 lidar

    NASA Technical Reports Server (NTRS)

    Ancellet, G. M.; Menzies, R. T.

    1986-01-01

    A pulsed TEA-CO2 lidar with coherent detection was used to measure the correlation time of backscatter from an ensemble of atmospheric aerosol particles which are illuminated by the pulsed radiation. The correlation time of the backscatter return signal is important in studies of atmospheric turbulence and its effects on optical propagation and backscatter. If the temporal coherence of the pulse is large enough, then the temporal coherence of the return signal is dominated by the turbulence and shear for a variety of interesting atmospheric conditions. Various techniques for correlation time measurement are discussed and evaluated.

  12. A Ground-Based 2-Micron DIAL System to Profile Tropospheric CO2 and Aerosol Distributions for Atmospheric Studies

    NASA Technical Reports Server (NTRS)

    Ismail, Syed; Koch, Grady; Abedin, Nurul; Refaat, Tamer; Rubio, Manuel; Davis, Kenneth; Miller, Charles; Singh, Upendra

    2006-01-01

    System will operate at a temperature insensitive CO2 line (2050.967 nm) with side-line tuning and off-set locking. Demonstrated an order of magnitude improvement in laser line locking needed for high precision measurements, side-line operation, and simultaneously double pulsing and line locking. Detector testing of phototransistor has demonstrated sensitivity to aerosol features over long distances in the atmosphere and resolve features approx. 100m. Optical systems that collect light onto small area detectors work well. Receiver optical designs are being optimized and data acquisition systems developed. CO2 line parameter characterization in progress In situ sensor calibration in progress for validation of DIAL CO2 system.

  13. Data Analysis of a Pulsed 2-micron Coherent Differential Absorption Lidar For Atmospheric CO2 Measurements

    NASA Astrophysics Data System (ADS)

    Lu, J.; Yu, J.

    2013-12-01

    The study of climate change requires precise measurement of the production, migration, and sinking of greenhouse gases. Carbon Dioxide (CO2) is one of the principal greenhouse gases. NASA Langley Research Center (LARC) has developed a pulsed 2-micron coherent differential absorption lidar (DiAL) for CO2 measurement, operating on the R30 absorption line. On April 5, 2010, the lidar instrument transmitted alternating On-line and Off-line pulses from LARC into a residential area in Poquoson, Virginia; while a passive in-situ sensor measured the local CO2 concentration. This paper outlines a procedure to estimate CO2 concentration from atmospheric lidar return signal using the DiAL method; our calculation produced results in line with the in-situ measurement and matched the current state of DiAL instrument accuracy. Data from April 5 is part of a series of experiments validating the measurement accuracy and precision of this lidar. After a summative verification, a packaged lidar may be installed on research aircraft to perform CO2 studies at a great range of latitudes throughout the year, and to discover sources, sinks, and migration trends for this key greenhouse gas. The following procedure is used to estimate CO2 concentration from atmospheric lidar return using the DiAL method. First, MATLAB software developed at LARC sorts the lidar return into On-only and Off-only files containing pulses of only that type. The sorted pulses are reexamined for quality based on the center frequency, energy, and power - unsatisfactory pulses are removed. A 512-point Fast Fourier Transform (FFT) with 256-point shift is performed on each pulse to discretize the atmospheric return signal according to 63 distance 'bins'. Next, comparing decay rates of the On-line and Off-line atmospheric return intensity with distance yields the Differential Absorption Optical Slope (DAOD), which is proportional to the concentration of the desired gas. Then, in-situ meteorological data - pressure

  14. Development of Compact 1.6 μm DIAL System for Measurement of Lower-Atmospheric CO2 Concentration Distribution

    NASA Astrophysics Data System (ADS)

    Nagasawa, C.; Shibata, Y.; Abo, M.

    2014-12-01

    For the detailed analysis of forest carbon dynamics and CO2 fluxes of urban area, the CO2 concentration measurement techniques with high spatial and temporal resolution are required in the lower atmosphere. We had developed the differential absorption lidar (DIAL) system to achieve high accurate measurements of vertical CO2 profiles and the vertical distribution of CO2 concentration from 2 km to 7 km altitude has been observed1. In order to measure the CO2 concentration distribution in the lower altitude, the dynamic range of the photon counter and the output power of transmitter of the CO2 DIAL have improved. We develope the compact 1.6 μm CO2 DIAL with the high-speed photon counter (10 GHz) and the small power transmitter to perform high-precision measurements of CO2 concentration profiles in the lower atmosphere. This compact mobile DIAL system has a 2 mJ OPG transmitter and a 25 cm coaxial telescope for measurements of limitted range. As the transmitter beam of this DIAL system is able to scan from -4 degree to 52 degree with elevation angle, the vertical distribution of lower CO2 concentration as well as the horizontal distribution from short range can be measured with high precision. The compact DIAL was conducted test observations and achieved successfully measurements of CO2 concentration profiles for the range from 0.25 to 3 km with integration time of 30 minutes and range resolution of 300 m. This work was financially supported by the System Development Program for Advanced Measurement and Analysis of the Japan Science and Technology Agency. REFERENCES Y. Shibata, C. Nagasawa, M. Abo, Proc. SPIE 8894, 889406 (2013); doi: 10.1117/12.2029359

  15. First open field measurements with a portable CO2 lidar/dial system for early forest fires detection

    NASA Astrophysics Data System (ADS)

    Gaudio, Pasquale; Gelfusa, Michela; Lupelli, Ivan; Malizia, Andrea; Moretti, Alessandro; Richetta, Maria; Serafini, Camilla; Bellecci, Carlo

    2011-11-01

    Lidar and dial are well established methods to explore the atmosphere. Different groups have already shown experimentally the possibility to measure the density variation of aerosol and particulate in the atmosphere due to plumes emitted in forest fires with this kind of systems. The aim of the present work is to demonstrate the capabilities of our mobile Lidar system, based on a CO2 laser, to detect forest fires and minimizing false alarms. For this purpose, our system can be operated in both lidar and dial configurations in sequence. The first Lidar measurement is performed to evaluate the variation of the local density into the atmosphere, using a nonabsorption water wavelength 10R18 (10.571 μm). If the returned signal reports a backscattering peak, the presence of a fire is probable. To confirm this hypothesis, a second dial measurement is carried out to reveal a second component emitted during the combustion process. The chosen second component is water vapour, which is, as it is well-known, largely produced during the first combustion stage. Measuring the water concentration peak after the detection of the aerosol density increment (referred to the standard mean atmospheric value) represents a good method to reduce false alarms with a dial system. In order to test this methodology, a first set of measurements has been performed in a field near the Engineering Faculty of the University of Rome "Tor Vergata". A quite small controlled-fire has been lighted into a box at a distance of about one kilometre from the system. The data acquired at the two wavelengths (10R18 and 10R20) have been averaged on 100 elastic backscattered Lidar signals. The first results confirm the effectiveness of the measurement strategy for reducing the number of false alarm preserving the early detection.

  16. Measurements of CO2 Concentration and Wind Profiles with A Scanning 1.6μm DIAL

    NASA Astrophysics Data System (ADS)

    Abo, M.; Shibata, Y.; Nagasawa, C.; Nagai, T.; Sakai, T.; Tsukamoto, M.

    2012-12-01

    Horizontal carbon dioxide (CO2) distribution and wind profiles are important information for understanding of the regional sink and source of CO2. The differential absorption lidar (DIAL) and the Doppler lidar with the range resolution is expected to bring several advantages over passive measurements. We have developed a new scanning 1.6μm DIAL and incoherent Doppler lidar system to perform simultaniously measurements of CO2 concentration and wind speed profiles in the atmosphere. The 1.6μm DIAL and Doppler lidar system consists of the Optical Parametric Generator (OPG) transmitter that excited by the LD pumped Nd:YAG laser with high repetition rate (500 Hz). The receiving optics include the near-infrared photomultiplier tube with high quantum efficiency operating at the photon counting mode, a fiber Bragg grating (FBG) filter to detct Doppler shift, and a 25 cm telescope[1][2]. Laser beam is transmitted coaxially and motorized scanning mirror system can scan the laser beam and field of view 0-360deg horizontally and 0-52deg vertically. We report the results of vertical CO2 scanning measurenents and vertical wind profiles. The scanning elevation angles were from 12deg to 24deg with angular step of 4deg and CO2 concentration profiles were obtained up to 1 km altitude with 200 m altitude resolution. We also obtained vertical wind vector profiles by measuring line-of-sight wind profiles at two azimuth angles with a fixed elevation angle 52deg. Vertical wind vector profiles were obtained up to 5 km altitude with 1 km altitude rasolution. This work was financially supported by the System Development Program for Advanced Measurement and Analysis of the Japan Science and Technology Agency. References [1] L. B. Vann, et al., "Narrowband fiber-optic phase-shifted Fabry-Perot Bragg grating filters for atmospheric water vapor lidar measurements", Appl. Opt., 44, pp. 7371-7377 (2005). [2] Y. Shibata, et al., "1.5μm incoherent Doppler lidar using a FBG filter", Proceedings

  17. Flight tests of a range-resolved airborne dial with two min-tea CO2 lasers

    NASA Technical Reports Server (NTRS)

    Itabe, T.; Ishizu, M.; Aruga, T.; Igarashi, T.; Asai, K.

    1986-01-01

    It is important to measure regional distributions of ozone concentrations in a short time for understanding a mechanism of photo-chemical smog development. An airborne Differential Absorption Lidar (DIAL) system with two low-power mini-TEA CO2 lasers was developed for measuring three-dimensional distributions of ozone in the lower troposphere. The CO2 DIAL is a nadir-looking system and is designed to measure ozone profiles between ground and airplane by using atmospheric aerosols as a distributed radar target. First flight test with a single laser were conducted in February 1985 over the Tokyo area. The system was operated at an altitude of 5000 ft. Results of the first flight tests show that the height profiles of the received power in the boundary layer were different between over land and ocean. The received power has to be inverted to an expression of a single optical parameter to see real aerosol distributions. Inversion of the lidar signal to the aerosol extinction was performed by using Klett's solution.

  18. Observation of vertcal CO2 concentration profiles in the lower-atmosphere using a compact direct detection 1.6 μm DIAL

    NASA Astrophysics Data System (ADS)

    Nagasawa, C.; Shibata, Y.; Abo, M.

    2015-12-01

    Knowledge of present carbon sources and sinks including their spatial profile and their variation in time is one of the essential informations for predicting future CO2 atmospheric concentration levels. Moewover, for the detailed analysis of forest carbon dynamics and CO2 fluxes of urban area, the CO2 concentration measurement techniques with high spatial and temporal resolution are required in the lower atmosphere. A differential absorption lidar (DIAL) is expected to measure atmospheric CO2 concentration profiles in the atmospheric boundary layer from a ground platform. We have succeeded to develop a compact direct detection 1.6 μm DIAL system for measuring CO2 concentration profiles in the lower atmosphere. This DIAL system consists of the optical parametric generator (OPG) transmitter that excited by the LD pumped Nd:YAG laser with high repetition rate and the receiving optics that included the near-infrared photomultiplier tube operating at the analog mode and the 25 cm telescope. We have succeeded in observing the daytime temporal change of vertical CO2 concentration profiles for the range from 0.25 to 2.5 km with integration time of 30 minutes and range resolution of 300 m. This compact direct detection CO2 DIAL is usefull for the estimation of CO2 flux. This work was financially supported by the System Development Program for Advanced Measurement and Analysis of the Japan Science and Technology Agency.

  19. Ground return signal simulation and retrieval algorithm of spaceborne integrated path DIAL for CO2 measurements

    NASA Astrophysics Data System (ADS)

    Liu, Bing-Yi; Wang, Jun-Yang; Liu, Zhi-Shen

    2014-11-01

    Spaceborne integrated path differential absorption (IPDA) lidar is an active-detection system which is able to perform global CO2 measurement with high accuracy of 1ppmv at day and night over ground and clouds. To evaluate the detection performance of the system, simulation of the ground return signal and retrieval algorithm for CO2 concentration are presented in this paper. Ground return signals of spaceborne IPDA lidar under various ground surface reflectivity and atmospheric aerosol optical depths are simulated using given system parameters, standard atmosphere profiles and HITRAN database, which can be used as reference for determining system parameters. The simulated signals are further applied to the research on retrieval algorithm for CO2 concentration. The column-weighted dry air mixing ratio of CO2 denoted by XCO2 is obtained. As the deviations of XCO2 between the initial values for simulation and the results from retrieval algorithm are within the expected error ranges, it is proved that the simulation and retrieval algorithm are reliable.

  20. A direct detection 1.6μm DIAL with three wavelengths for high accuracy measurements of vertical CO2 concentration and temperature profiles

    NASA Astrophysics Data System (ADS)

    Shibata, Yasukuni; Nagasawa, Chikao; Abo, Makoto

    2013-10-01

    The accurate vertical CO2 profiles in the troposphere are highly desirable in the inverse techniques to improve quantification and understanding of the global budget of CO2 and also global climate changes. Moreover, wind information is an important parameter for transport simulations and inverse estimation of surface CO2 flux. A differential absorption lidar (DIAL) is an attractive method for obtaining vertical CO2 profiles and we have developed an 1.6μm DIAL system to perform simultaneous measurements of CO2 concentration, atmospheric temperature profile and wind profile. The absorption cross sections of gas and air density depends on atmospheric temperature and pressure. Then precise temperature and pressure profiles are necessary for accurate CO2 mixing ratio measurement by DIAL. Laser beams of three wavelengths around a CO2 absorption line are transmitted alternately to the atmosphere for simultaneous measurements of CO2 concentration and temperature. The receiving optics include the near-infrared photomultiplier tube and a fiber Bragg grating (FBG) filter to detect a Doppler shift.

  1. 1.6 μm DIAL Measurement and Back Trajectory Analysis of CO2 Concentration Profiles in the Lower-Atmosphere

    NASA Astrophysics Data System (ADS)

    Shibata, Y.; Nagasawa, C.; Abo, M.

    2016-12-01

    Carbon dioxide (CO2) is the primary greenhouse gas emitted through human activities. In addition to the ground level CO2 network, vertical CO2 concentration profiles also play an important role for the estimation of the carbon budget and global warming in the inversion method. Especially, for the detailed analysis of forest carbon dynamics and CO2 fluxes of urban area, vertical CO2 concentration profiles with high spatial and temporal resolution in the lower atmosphere have been conducted by a differential absorption lidar (DIAL). We have observed several vertical profiles of CO2 concentrations for nighttime and daytime from 0.25 to 2.5 km altitude with range resolution of 300 m and integration time of 1 hour. In order to extract information on the origin of the CO2 masses, one day back trajectories were calculated by using a three dimensional (3-D) atmospheric transport model. In many cases, CO2 low concentration layers of over 1.5km altitude were flown by westerly winds from the forest. In another case, high concentration layers of CO2 were flown from the urban areas. As the spectra of absorption lines of any molecules are influenced basically by the temperature in the atmosphere, laser beams of three wavelengths around a CO2 absorption spectrum are transmitted alternately to the atmosphere for simultaneous measurements of CO2 concentration and temperature profiles. Moreover, a few processing algorithms of CO2-DIAL are also performed for improvement of measurement accuracy. For computation of trajectories and drawing their figures, the JRA-25 data provided by the cooperative research project for the JRA-25 long-term reanalysis of the Japan Meteorological Agency (JMA) and the Central Research Institute of Electric Power Industry (CRIEPI) and the NIPR trajectory model (Tomikawa and Sato, 2005; http://firp-nitram.nipr.ac.jp) were used. This work was financially supported by the System Development Program for Advanced Measurement and Analysis of the Japan Science and

  2. Characteristics of the OPG System USIG Quasiphase-Matched Nonlinear Crystals for 1.6 μm CO2 Dial

    NASA Astrophysics Data System (ADS)

    Shibata, Yasukuni; Nagasawa, Chikao; Abo, Makoto

    2016-06-01

    We have developed a direct detection 1.6 μm differential absorption lidar (DIAL) technique to perform range-resolved measurements of vertical CO2 concentration profiles in the atmosphere. Our 1.6 μm DIAL system consists of the optical parametric generator (OPG) and amplifier (OPA) transmitter that excited by the LD pumped Nd:YAG laser with high repetition rate (500 Hz). The OPG system consists of a quasi-phase-matched (QPM) crystal and does not need a cavity. The output power of the OPA system is 6 mJ, the full width at half maximum (FWHM) of the spectrum is about 280 MHz and spectrum purity is 91.0 +- 0.2 ~ 0.5%. CO2 concentration error from fluctuation of the spectrum purity is 0.3% at 6 km altitude and 0.4 % at 10 km altitude.

  3. High Power OPO Laser and wavelength-controlled system for 1.6μm CO2-DIAL

    NASA Astrophysics Data System (ADS)

    Abo, M.; Nagasawa, C.; Shibata, Y.

    2009-12-01

    Unlike the existing 2.0μm CO2-DIAL, a high-energy pulse laser operating in the 1.6μm absorption band of CO2 has not been realized. Quasi phase matching (QPM) devices have high conversion efficiency and high beam quality due to their higher nonlinear optical coefficient. We adapt the PPMgLT crystal as the QPM device. The PPMgLT crystal had 3mm × 3mm apertures, and the periodically poled period was 30.9 μm, with the duty ratio close to the ideal value of 0.5. The beam quality of the pumping laser was exceed M2 ≥1.2. The repetition rate was 400 Hz and the energy was 35 mJ. The pumping laser pulse was injection-seeded by the continuous-wave (CW) fiber laser, which had a narrow spectrum. The pulse pumped the PPMgLT crystal in the ring cavity with a single pass through the dielectric mirror. The PPMgLT crystal was mounted on a copper holder, and the temperature was maintained at 40 °C using a Peltier module. The holder’s temperature was stabilized to within 0.01 °C when the copper holder was covered with a plastic case. The OPO ring cavity was a singly resonant oscillator optimized for the signal wave. Single-frequency oscillation of the PPMgLT OPO was achieved by injection seeding, as described in the following. The injection seeder was a DFB laser having a power of 30mW with a 1MHz oscillation spectrum. Their oscillation wavelength was coarse tuned by temperature and fine tuned by adjusting injection currents. The partial power of the online wavelength was split in the wavelength control unit. We locked the DFB laser as an injection seeder of the online wavelength onto the line center by referencing the fiber coupled multipath gas cell (path length 800mm) containing pure CO2 at a pressure of 700 Torr. Stabilization was estimated to within 1.8MHz rms of the line center of the CO2 absorption line by monitoring the feedback signal of a wavelength-controlled unit. Injection seeding of the PPMgLT OPO was performed by matching the cavity length to the seeder

  4. In-cell measurements of smoke backscattering coefficients using a CO2 laser system for application to lidar-dial forest fire detection

    NASA Astrophysics Data System (ADS)

    Bellecci, Carlo; Gaudio, Pasquale; Gelfusa, Michela; Lo Feudo, Teresa; Murari, Andrea; Richetta, Maria; de Leo, Leonerdo

    2010-12-01

    In the lidar-dial method, the amount of the water vapor present in the smoke of the vegetable fuel is detected to reduce the number of false alarms. We report the measurements of the smoke backscattering coefficients for the CO2 laser lines 10R20 and 10R18 as determined in an absorption cell for two different vegetable fuels (eucalyptus and conifer). These experimental backscattering coefficients enable us to determine the error to be associated to the water vapor measurements when the traditional first-order approximation is assumed. We find that this first-order approximation is valid for combustion rates as low as 100 g/s.

  5. 315mJ, 2-micrometers Double-Pulsed Coherent Differential Absorption Lidar Transmitter for Atmospheric CO2 Sensing

    NASA Technical Reports Server (NTRS)

    Yu, Jirong; Trieu, Bo; Bai, Yingxin; Koch, Grady; Chen, Songsheng; Petzar, Paul; Singh, Upendra N.; Kavaya, Michael J.; Beyon, Jeffrey

    2010-01-01

    The design of a double pulsed, injection seeded, 2-micrometer compact coherent Differential absorption Lidar (DIAL) transmitter for CO2 sensing is presented. This system is hardened for ground and airborne applications. The design architecture includes three continuous wave lasers which provide controlled on and off line seeding, injection seeded power oscillator and a single amplifier operating in double pass configuration. As the derivative a coherent Doppler wind lidar, this instrument has the added benefit of providing wind information. The active laser material used for this application is a Ho: Tm:YLF crystal operates at the eye-safe wavelength. The 3-meter long folded ring resonator produces energy of 130-mJ (90/40) with a temporal pulse length around 220 nanoseconds and 530 nanosecond pulses for on and off lines respectively. The separation between the two pulses is on the order of 200 microseconds. The line width is in the order of 2.5MHz and the beam quality has an M(sup 2) of 1.1 times diffraction limited beam. A final output energy for a pair of both on and off pulses as high as 315 mJ (190/125) at a repetition rate of 10 Hz is achieved. The operating temperature is set around 20 C for the pump diode lasers and 10 C for the rod. Since the laser design has to meet high-energy as well as high beam quality requirements, close attention is paid to the laser head design to avoid thermal distortion in the rod. A side-pumped configuration is used and heat is removed uniformly by passing coolant through a tube slightly larger than the rod to reduce thermal gradient. This paper also discusses the advantage of using a long upper laser level life time laser crystal for DIAL application. In addition issues related to injection seeding with two different frequencies to achieve a transform limited line width will be presented.

  6. Differential Absorption Lidar (DIAL) in Alberta: A New Remote Sensing Tool for Wide Area Measurement of Particulates, CO2, and CH4 Emissions from Energy Extraction and Production Sites

    NASA Astrophysics Data System (ADS)

    Wojcik, M.; Lemon, R.; Crowther, B. G.; Valupadas, P.; Fu, L.; Yang, Z.; Huda, Q.; Leung, B.; Chambers, A.

    2014-12-01

    Alberta Environmental Monitoring, Evaluation and Reporting Agency (AEMERA) in cooperation with the Space Dynamics Laboratory (SDL) of Utah State University, have developed a mobile DIAL sensor designed specifically for particle, CO2 and CH4 emissions measurement. Rapid expansion of the oil and gas industry in Alberta, including the oil sands, has challenged the Alberta Government to keep pace in its efforts to monitor and mitigate the environmental impacts of development. The limitations of current monitoring systems has pushed the provincial government to seek out advanced sensing technologies such as differential absorption lidar (DIAL) to help assess the impact of energy development and industrial operations. This instrument is housed inside a 36' trailer and can be quickly staged and used to characterize source emissions and to locate fugitive leaks. DIAL is capable of measuring concentrations for carbon dioxide (CO2) and methane (CH4) at ranges of up to 3 km with a spatial resolution of 1.5 m. DIAL can map both CO2 and CH4, as well as particulate matter (PM) in a linear fashion; by scanning the laser beam in both azimuth and elevation, DIAL can create images of emissions concentrations and ultimately can be used to determine emission factors, locate fugitive leaks, assess plume dispersion and confirm air dispersion modeling. The DIAL system has been deployed at a landfill, a coal-fired power plant, and an oil sands production area. A system overview of the DIAL instrument and recent results will be discussed.

  7. The Mobile Atmospheric Pollutant Mapping (MAPM) System - A coherent CO2, DIAL system

    NASA Technical Reports Server (NTRS)

    Grant, William B.

    1989-01-01

    The hardware for the Mobile Atmospheric Pollutant Mapping System is described. Measurement results using the hardware are reported along with absorption coefficients and measurement sensitivities for a number of molecular species. The factor that limit measurement accuracy and range are considered.

  8. Development of a Micro Pulsed Lidar and a Singly-Resonant Optical Parametric Oscillator for CO2 Dial for Use in Atmospheric Studies

    NASA Astrophysics Data System (ADS)

    Chantjaroen, Chat

    According to the Fifth Assessment Report (AR5) from the Intergovernmental Panel on Climate Change (IPCC), aerosols and CO2 are the largest contributors to anthropogenic radiative forcing--net negative for aerosols and positive for CO2. This relates to the amount of impact that aerosols and CO2 can have on our atmosphere and climate system. CO2 is the predominant greenhouse gas in the atmosphere and causes great impacts on our climate system. Recent studies show that a less well known atmospheric component--aerosols, which are solid particles or liquid droplets suspended in air, can cause great impact on our climate system too. They can affect our climate directly by absorbing and scattering sunlight to warm or cool our climate. They can also affect our climate indirectly by affecting cloud microphysical properties. Typically sulfate aerosols or sea salts act as condensation nuclei for clouds to form. Clouds are estimated to shade about 60% of the earth at any given time. They are preventing much of the sunlight from reaching the earth's surface and are helping with the flow of the global water cycle. These are what permit lifeforms on earth. In the IPCC report, both aerosols and CO2 also have the largest uncertainties and aerosols remains at a low level of scientific understanding. These indicate the need of more accurate measurements and that new technologies and instruments needs to be developed. This dissertation focuses on the development of two instruments--a scannable Micro-Pulsed Lidar (MPL) for atmospheric aerosol measurements and an Optical Parametric Oscillator (OPO) for use as a transmitter in a Differential Absorption Lidar (DIAL) for atmospheric CO2 measurements. The MPL demonstrates successful measurements of aerosols. It provides the total aerosol optical depth (AOD) and aerosol lidar ratio (Sa) that agree well with an instrument used by the Aerosol Robotic Network (AERONET). It also successfully provides range-resolved information about aerosols

  9. Development of the 1.6μm OPG/OPA system wavelength-controlled precisely for CO2 DIAL

    NASA Astrophysics Data System (ADS)

    Abo, M.; Shibata, Y.; Nagasawa, C.

    2010-12-01

    We developed an optical parametric oscillator (OPO) laser system for 1.6μm CO2 DIAL1). In order to improve the measurement accuracy of CO2 profiles, development of high power and wavelength stabilized laser system has been conducted. We report a new high-power 1.6μm laser transmitter based on a parametric master oscillator-power amplifier (MOPA) system pumped by a LD-pumped Q-switched Nd:YAG laser which has the injection seed laser locked to the iodine absorption line. The master oscillator is an optical parametric generator (OPG), based on an MgO-doped periodically poled LiTaO3 (PPMgLT) crystal. The OPOs require either active control of the cavity length or slight misalignment of the cavity. On the other hand, the OPGs do not require a cavity and instead rely on sufficient conversion efficiency to be obtained with a single pass through the crystal. The single-frequency oscillation of the OPG was achieved by injection seeding. The 1.6μm emission of the OPG is amplified by two-stage optical parametric amplifiers (OPAs). The each PPMgLT crystal was mounted on the copper holder, and the temperature control of the each holder was carried out within 0.01 K. The wavelength feedback system of the Nd:YAG seed laser is performed with the side locking of the iodine absorption spectrum (line No.1107) and the frequency stability is realized within 10 MHz rms. Stabilization of the 1.6μm DFB seed laser is estimated to within 4 MHz rms at the CO2 absorption line center and within 1.8 MHz rms at the CO2 absorption line slope using the wavelength control unit. We demonstrated single-longitudinal-mode emission with the OPG and two OPAs. The beam quality was TEM00 mode, the pulse energy was 12 mJ at 500 Hz repetition rate and the frequency stability was less than 10MHz rms. The unique performances of this optical parametric system make a relevant transmitter for CO2 DIAL. This work was financially supported by the System Development Program for Advanced Measurement and Analysis

  10. Ground-based integrated path coherent differential absorption lidar measurement of CO2: foothill target return

    NASA Astrophysics Data System (ADS)

    Ishii, S.; Koyama, M.; Baron, P.; Iwai, H.; Mizutani, K.; Itabe, T.; Sato, A.; Asai, K.

    2013-05-01

    The National Institute of Information and Communications Technology (NICT) has made a great deal of effort to develop a coherent 2 μm differential absorption and wind lidar (Co2DiaWiL) for measuring CO2 and wind speed. First, coherent Integrated Path Differential Absorption (IPDA) lidar experiments were conducted using the Co2DiaWiL and a foothill target (tree and ground surface) located about 7.12 km south of NICT on 11, 27, and 28 December 2010. The detection sensitivity of a 2 μm IPDA lidar was examined in detail using the CO2 concentration measured by the foothill reflection. The precisions of CO2 measurements for the foothill target and 900, 4500 and 27 000 shot pairs were 6.5, 2.8, and 1.2%, respectively. The results indicated that a coherent IPDA lidar with a laser operating at a high pulse repetition frequency of a few tens of KHz is necessary for XCO2 (column-averaged dry air mixing ratio of CO2) measurement with a precision of 1-2 ppm in order to observe temporal and spatial variations in the CO2. Statistical comparisons indicated that, although a small amount of in situ data and the fact that they were not co-located with the foothill target made comparison difficult, the CO2 volume mixing ratio obtained by the Co2DiaWiL measurements for the foothill target and atmospheric returns was about -5 ppm lower than the 5 min running averages of the in situ sensor. Not only actual difference of sensing volume or the natural variability of CO2 but also the fluctuations of temperature could cause this difference. The statistical results indicated that there were no biases between the foothill target and atmospheric return measurements. The 2 μm coherent IPDA lidar can detect the CO2 volume mixing ratio change of 3% in the 5 min signal integration. In order to detect the position of the foothill target, to measure a range with a high SNR (signal-to-noise ratio), and to reduce uncertainty due to the presence of aerosols and clouds, it is important to make a

  11. A tunable coherent CO2 lidar for measurements of atmospheric aerosol backscatter and attenuation

    NASA Technical Reports Server (NTRS)

    Menzies, R. T.

    1983-01-01

    A coherent laser radar system using a grating-tunable, injection-locked TEA-CO2 transmitter is being used to measure the altitude dependence of atmospheric aerosol backscatter and attenuation at a variety of CO2 laser wavelengths in the 9-11 micron region. Injection control of the TEA-CO2 laser allows one to obtain Single-Longitudinal-Mode (SLM) pulses which will follow the frequency of the injected radiation if the TEA laser cavity length is adjusted so that a cavity resonance is in proximity with the injected signal frequency, and if various additional conditions are satisfied. Requirements for generation of SLM pulses in this manner from a TEA CO2 laser with an unstable resonator cavity will be discussed. Procedures used for quantitative range-gated measurements of aerosol backscatter and attenuation will also be discussed.

  12. High power CO2 coherent ladar haven't quit the stage of military affairs

    NASA Astrophysics Data System (ADS)

    Zhang, Heyong

    2015-05-01

    The invention of the laser in 1960 created the possibility of using a source of coherent light as a transmitter for a laser radar (ladar). Coherent ladar shares many of the basic features of more common microwave radars. However, it is the extremely short operating wavelength of lasers that introduces new military applications, especially in the area of missile identification, space target tracking, remote rang finding, camouflage discrimination and toxic agent detection. Therefore, the most popular application field such as laser imaging and ranging were focused on CO2 laser in the last few decades. But during the development of solid state and fiber laser, some people said that the CO2 laser will be disappeared and will be replaced by the solid and fiber laser in the field of military and industry. The coherent CO2 laser radar will have the same destiny in the field of military affairs. However, to my opinion, the high power CO2 laser will be the most important laser source for laser radar and countermeasure in the future.

  13. Two-beam femtosecond coherent anti-Stokes Raman scattering for thermometry on CO2

    NASA Astrophysics Data System (ADS)

    Kerstan, M.; Makos, I.; Nolte, S.; Tünnermann, A.; Ackermann, R.

    2017-01-01

    We show that two-beam femtosecond coherent anti-Stokes Raman scattering can be effectively used for thermometry on CO2 for temperatures between ˜100 °C and ˜600 °C at a maximum pressure of 8.5 bar. The temperature measurement is based on probing the vibrationally excited states of CO2, using a ˜7 fs pump/Stokes pulse and a narrowband (˜0.3 nm) probe pulse. The temperatures can be derived from a single spectrum, obviating the need for a delay scan or a chirped probe pulse.

  14. Stochastic method for determining the coherence length of a TEA CO2 laser

    NASA Astrophysics Data System (ADS)

    Codnia, J.; Gómez, N. D.; Azcárate, M. L.

    2013-12-01

    In this work the results of the measurement of the coherence length of a TEA CO2 laser developed in DEILAP are presented. A Michelson interferometer of about 5 m of optical path length difference was built for this purpose. A motorized translation optical mount was placed in one arm in order to enable the variation of the optical path length in many wavelengths. The length of the other arm was varied manually in steps of several tens of centimeters. Spatial filtering forced the laser to oscillate in a single transverse mode, TEM00. An innovative stochastic technique for data analysis allowed determining the amount of longitudinal modes, the amplitude and the individual average coherence length of each mode as well as the global coherence length of the laser. This technique was later compared with a method based on the analysis of the Fourier transform of the time series obtained at the interferometer input.

  15. Dual-Pump Coherent Anti-Stokes Raman Scattering Temperature and CO2 Concentration Measurements

    NASA Technical Reports Server (NTRS)

    Lucht, Robert P.; Velur-Natarajan, Viswanathan; Carter, Campbell D.; Grinstead, Keith D., Jr.; Gord, James R.; Danehy, Paul M.; Fiechtner, G. J.; Farrow, Roger L.

    2003-01-01

    Measurements of temperature and CO2 concentration using dual-pump coherent anti-Stokes Raman scattering, (CARS) are described. The measurements were performed in laboratory flames,in a room-temperature gas cell, and on an engine test stand at the U.S. Air Force Research Laboratory, Wright-Patterson Air Force Base. A modeless dye laser, a single-mode Nd:YAG laser, and an unintensified back-illuminated charge-coupled device digital camera were used for these measurements. The CARS measurements were performed on a single-laser-shot basis. The standard deviations of the temperatures and CO2 mole fractions determined from single-shot dual-pump CARS spectra in steady laminar propane/air flames were approximately 2 and 10% of the mean values of approximately 2000 K and 0.10, respectively. The precision and accuracy of single-shot temperature measurements obtained from the nitrogen part of the dual-pump CARS system were investigated in detail in near-adiabatic hydrogen/air/CO2 flames. The precision of the CARS temperature measurements was found to be comparable to the best results reported in the literature for conventional two-laser, single-pump CARS. The application of dual-pump CARS for single-shot measurements in a swirl-stabilized combustor fueled with JP-8 was also demonstrated.

  16. Spatial structure and coherence properties of Brillouin scatter from CO2 laser-target interaction

    NASA Astrophysics Data System (ADS)

    Mitchel, G. R.; Grek, B.; Johnston, T. W.; Pépin, H.; Church, P.; Martin, F.

    1982-05-01

    The spatial structure and coherence properties of 10.6-μm light scattered from CO2 laser-target interactions in oblique incidence show many unexpected features. It is found that the Brillouin backscatter is neither a phase conjugate nor a ray retrace of the incident beam. Rather, it shows a preference for scattering directions other than those exactly antiparallel to the incident beam, apparently related to the angular distribution of the scattering source and also of the plasma corona that serves as the Brillouin amplifying medium. As well, the backscatter phasefront is strongly perturbed with respect to the incident phasefront. This is an indication of turbulence in the corona and/or memory of the structure in the source that is then amplified. Small-scale structures seen in the reimaged backscatter are due to phase perturbation and cannot be simply interpreted as geometric images of a (filamented) source. The phasefront of light that is scattered obliquely from the plasma is much more coherent.

  17. The influence of biomass energy consumption on CO2 emissions: a wavelet coherence approach.

    PubMed

    Bilgili, Faik; Öztürk, İlhan; Koçak, Emrah; Bulut, Ümit; Pamuk, Yalçın; Muğaloğlu, Erhan; Bağlıtaş, Hayriye H

    2016-10-01

    In terms of today, one may argue, throughout observations from energy literature papers, that (i) one of the main contributors of the global warming is carbon dioxide emissions, (ii) the fossil fuel energy usage greatly contributes to the carbon dioxide emissions, and (iii) the simulations from energy models attract the attention of policy makers to renewable energy as alternative energy source to mitigate the carbon dioxide emissions. Although there appears to be intensive renewable energy works in the related literature regarding renewables' efficiency/impact on environmental quality, a researcher might still need to follow further studies to review the significance of renewables in the environment since (i) the existing seminal papers employ time series models and/or panel data models or some other statistical observation to detect the role of renewables in the environment and (ii) existing papers consider mostly aggregated renewable energy source rather than examining the major component(s) of aggregated renewables. This paper attempted to examine clearly the impact of biomass on carbon dioxide emissions in detail through time series and frequency analyses. Hence, the paper follows wavelet coherence analyses. The data covers the US monthly observations ranging from 1984:1 to 2015 for the variables of total energy carbon dioxide emissions, biomass energy consumption, coal consumption, petroleum consumption, and natural gas consumption. The paper thus, throughout wavelet coherence and wavelet partial coherence analyses, observes frequency properties as well as time series properties of relevant variables to reveal the possible significant influence of biomass usage on the emissions in the USA in both the short-term and the long-term cycles. The paper also reveals, finally, that the biomass consumption mitigates CO2 emissions in the long run cycles after the year 2005 in the USA.

  18. Multifrequency dial sensing of the atmospheric gaseous constituents using the first and second harmonics of a tunable CO2 laser radiation

    NASA Technical Reports Server (NTRS)

    Zuev, V. E.; Andreev, Y. M.; Voevodin, V. G.; Gribenyukov, A. I.; Kapitanov, V. A.; Sosnin, A. V.; Stuchebrov, G. A.; Khmelnitskii, G. S.

    1986-01-01

    The results of field measurements of concentration of some gaseous components of the atmosphere along the paths, in Sofia, Bulgaria, using a gas analyzer based on the use of a CO2 laser radiation frequency-doubled with ZnGeP2 monocrystals are presented. The gas analyzer is a traditional long path absorption meter. Radiation from the tunable CO2 laser of low pressure and from an additional He-Ne laser is directed to a colliminating hundredfold Gregori telescope with a 300 mm diameter of the principal mirror. The dimensions of the mirrors of a retroreflector 500 x 500 mm and a receiving telescope allow one to totally intercept the beam passed through the atmospheric layer under study and back.

  19. Design of Control Software for a High-Speed Coherent Doppler Lidar System for CO2 Measurement

    NASA Technical Reports Server (NTRS)

    Vanvalkenburg, Randal L.; Beyon, Jeffrey Y.; Koch, Grady J.; Yu, Jirong; Singh, Upendra N.; Kavaya, Michael J.

    2010-01-01

    The design of the software for a 2-micron coherent high-speed Doppler lidar system for CO2 measurement at NASA Langley Research Center is discussed in this paper. The specific strategy and design topology to meet the requirements of the system are reviewed. In order to attain the high-speed digitization of the different types of signals to be sampled on multiple channels, a carefully planned design of the control software is imperative. Samples of digitized data from each channel and their roles in data analysis post processing are also presented. Several challenges of extremely-fast, high volume data acquisition are discussed. The software must check the validity of each lidar return as well as other monitoring channel data in real-time. For such high-speed data acquisition systems, the software is a key component that enables the entire scope of CO2 measurement studies using commercially available system components.

  20. High-energy single-longitudinal mode nearly diffraction-limited optical parametric source with 3 MHz frequency stability for CO2 DIAL.

    PubMed

    Raybaut, Myriam; Schmid, Thomas; Godard, Antoine; Mohamed, Ajmal K; Lefebvre, Michel; Marnas, Fabien; Flamant, Pierre; Bohman, Axel; Geiser, Peter; Kaspersen, Peter

    2009-07-01

    We report on a 2.05 microm nanosecond master oscillator power amplifier optical parametric source for CO2 differential-absorption lidar. The master oscillator consists of an entangled-cavity nanosecond optical parametric oscillator based on a type II periodically poled lithium niobate crystal that provides highly stable single-longitudinal-mode radiation. The signal emission is amplified by a multistage parametric amplifier to generate up to 11 mJ in a nearly diffraction-limited beam with an M2 quality factor of approximately 1.5 while maintaining single-longitudinal-mode emission with a frequency stability better than 3 MHz rms. This approach can be readily applied to the detection of various greenhouse gases.

  1. Measurement of Range-Resolved Water Vapor Concentration by Coherent CO2 Differential Absorption Lidar.

    DTIC Science & Technology

    1984-03-01

    behavior is similar to that predicted by Willets and Harris [112], who postulated that the initial chirp results from the presence of free electrons in the...measured chirp characteristics of a number of CO 2 TE systems, including the NOAA lidar with those predicted by the Willetts and Harris scaling parameters...the winter months, measurements between October and March were performed with the lidar pcinting roughly horizontally. Such measuremetIts poter .- tially

  2. Energy Measurement Studies for CO2 Measurement with a Coherent Doppler Lidar System

    NASA Technical Reports Server (NTRS)

    Beyon, Jeffrey Y.; Koch, Grady J.; Vanvalkenburg, Randal L.; Yu, Jirong; Singh, Upendra N.; Kavaya, Michael J.

    2010-01-01

    The accurate measurement of energy in the application of lidar system for CO2 measurement is critical. Different techniques of energy estimation in the online and offline pulses are investigated for post processing of lidar returns. The cornerstone of the techniques is the accurate estimation of the spectrum of lidar signal and background noise. Since the background noise is not the ideal white Gaussian noise, simple average level estimation of noise level is not well fit in the energy estimation of lidar signal and noise. A brief review of the methods is presented in this paper.

  3. In situ backscatter measurements over Pacific Ocean using two coherent focused CO2 lidars

    NASA Technical Reports Server (NTRS)

    Rothermel, Jeffry; Jones, William D.; Srivastava, Vandana; Jarzembski, Maurice; Hampton, Diana

    1991-01-01

    Preliminary results of CS lidar measurements over the Pacific Ocean using two CO2 Doppler lidars operating at 9.1 and 10.6 microns are presented. SNR calculations during real-time and postprocessing were performed using a multistep signal search and signal power estimation algorithm optimized for weak signal conditions. Typical aerosol structure observed in the troposphere was found to consist of a boundary layer, a cloud-pumped layer, and a clean background layer; backscatter from cloud-free air was found to vary over three to four orders of magnitude or more.

  4. Can CO2 Turbulent Flux Be Measured by Lidar? A Preliminary Study

    NASA Technical Reports Server (NTRS)

    Gilbert, Fabien; Koch, Grady; Beyon, Jeffrey Y.; Hilton, Timothy W.; Davis, Kenneth J.; Andrews, Arlyn; Flamant, Pierre H.; Singh, Upendra N.

    2011-01-01

    The vertical profiling ofCO2 turbulent fluxes in the atmospheric boundary layer (ABL) is investigated using a coherent differential absorption lidar (CDIAL) operated nearby a tall tower in Wisconsin during June 2007. A CDIAL can perform simultaneous range-resolved CO2 DIAL and velocity measurements. The lidar eddy covariance technique is presented. The aims of the study are (i) an assessment of performance and current limitation of available CDIAL for CO2 turbulent fluxes and (ii) the derivation of instrument specifications to build a future CDIAL to perform accurate range-resolved CO2 fluxes. Experimental lidar CO2 mixing ratio and vertical velocity profiles are successfully compared with in situ sensors measurements. Time and space integral scales of turbulence in the ABL are addressed that result in limitation for time averaging and range accumulation. A first attempt to infer CO2 fluxes using an eddy covariance technique with currently available 2-mm CDIAL dataset is reported.

  5. Can CO2 Turbulent Flux Be Measured by Lidar? A Preliminary Study

    NASA Technical Reports Server (NTRS)

    Gilbert, Fabien; Koch, Grady; Beyon, Jeffrey Y.; Hilton, Timothy W.; Davis, Kenneth J.; Andrews, Arlyn; Flamant, Pierre H.; Singh, Upendra N.

    2011-01-01

    The vertical profiling ofCO2 turbulent fluxes in the atmospheric boundary layer (ABL) is investigated using a coherent differential absorption lidar (CDIAL) operated nearby a tall tower in Wisconsin during June 2007. A CDIAL can perform simultaneous range-resolved CO2 DIAL and velocity measurements. The lidar eddy covariance technique is presented. The aims of the study are (i) an assessment of performance and current limitation of available CDIAL for CO2 turbulent fluxes and (ii) the derivation of instrument specifications to build a future CDIAL to perform accurate range-resolved CO2 fluxes. Experimental lidar CO2 mixing ratio and vertical velocity profiles are successfully compared with in situ sensors measurements. Time and space integral scales of turbulence in the ABL are addressed that result in limitation for time averaging and range accumulation. A first attempt to infer CO2 fluxes using an eddy covariance technique with currently available 2-mm CDIAL dataset is reported.

  6. Side-line tunable laser transmitter for differential absorption lidar measurements of CO2: design and application to atmospheric measurements.

    PubMed

    Koch, Grady J; Beyon, Jeffrey Y; Gibert, Fabien; Barnes, Bruce W; Ismail, Syed; Petros, Mulugeta; Petzar, Paul J; Yu, Jirong; Modlin, Edward A; Davis, Kenneth J; Singh, Upendra N

    2008-03-01

    A 2 microm wavelength, 90 mJ, 5 Hz pulsed Ho laser is described with wavelength control to precisely tune and lock the wavelength at a desired offset up to 2.9 GHz from the center of a CO(2) absorption line. Once detuned from the line center the laser wavelength is actively locked to keep the wavelength within 1.9 MHz standard deviation about the setpoint. This wavelength control allows optimization of the optical depth for a differential absorption lidar (DIAL) measuring atmospheric CO(2) concentrations. The laser transmitter has been coupled with a coherent heterodyne receiver for measurements of CO(2) concentration using aerosol backscatter; wind and aerosols are also measured with the same lidar and provide useful additional information on atmospheric structure. Range-resolved CO(2) measurements were made with <2.4% standard deviation using 500 m range bins and 6.7 min? (1000 pulse pairs) integration time. Measurement of a horizontal column showed a precision of the CO(2) concentration to <0.7% standard deviation using a 30 min? (4500 pulse pairs) integration time, and comparison with a collocated in situ sensor showed the DIAL to measure the same trend of a diurnal variation and to detect shorter time scale CO(2) perturbations. For vertical column measurements the lidar was setup at the WLEF tall tower site in Wisconsin to provide meteorological profiles and to compare the DIAL measurements with the in situ sensors distributed on the tower up to 396 m height. Assuming the DIAL column measurement extending from 153 m altitude to 1353 m altitude should agree with the tower in situ sensor at 396 m altitude, there was a 7.9 ppm rms difference between the DIAL and the in situ sensor using a 30 min? rolling average on the DIAL measurement.

  7. A Two Micron Coherent Differential Absorption Lidar Development

    NASA Technical Reports Server (NTRS)

    Yu, Jirong; Petros, Mulugeta; Chen, Songsheng; Bai, Yingxin; Petzar, Paul J.; Trieu, Bo C.; Koch, Grady J.; Beyon, Jeffrey Y.; VanValkenburg, Randal L.; Kavaya, Michael J.; Singh, Upendra N.

    2010-01-01

    A pulsed, 2-micron coherent Differential Absorption Lidar (DIAL)/Integrated Path Differential Absorption (IPDA) transceiver, developed under the Laser Risk Reduction Program (LRRP) at NASA, is integrated into a fully functional lidar instrument. This instrument measures atmospheric CO2 profiles (by DIAL) from a ground platform. It allows the investigators to pursue subsequent in science-driven deployments, and provides a unique tool for Active Sensing of CO2 Emissions over Night, Days, and Seasons (ASCENDS) validation that was strongly advocated in the recent ASCENDS Workshop. Keywords: Differential Absorption Lidar, Near Infrared Laser,

  8. Atmospheric CO2 measurements with a 2 μm airborne laser absorption spectrometer employing coherent detection.

    PubMed

    Spiers, Gary D; Menzies, Robert T; Jacob, Joseph; Christensen, Lance E; Phillips, Mark W; Choi, Yonghoon; Browell, Edward V

    2011-05-10

    We report airborne measurements of CO(2) column abundance conducted during two 2009 campaigns using a 2.05 μm laser absorption spectrometer. The two flight campaigns took place in the California Mojave desert and in Oklahoma. The integrated path differential absorption (IPDA) method is used for the CO(2) column mixing ratio retrievals. This instrument and the data analysis methodology provide insight into the capabilities of the IPDA method for both airborne measurements and future global-scale CO(2) measurements from low Earth orbit pertinent to the NASA Active Sensing of CO(2) Emissions over Nights, Days, and Seasons mission. The use of a favorable absorption line in the CO(2) 2 μm band allows the on-line frequency to be displaced two (surface pressure) half-widths from line center, providing high sensitivity to the lower tropospheric CO(2). The measurement repeatability and measurement precision are in good agreement with predicted estimates. We also report comparisons with airborne in situ measurements conducted during the Oklahoma campaign.

  9. Coherent laser radar at 2 microns using solid-state lasers

    NASA Technical Reports Server (NTRS)

    Henderson, Sammy W.; Suni, Paul J. M.; Hale, Charley P.; Hannon, Stephen M.; Magee, James R.; Bruns, Dale L.; Yuen, Eric H.

    1993-01-01

    Coherent laser radar systems using 2-micron Tm- and Tm, Ho-doped solid-state lasers are useful for the remote range-resolved measurement of atmospheric winds, aerosol backscatter, and DIAL measurements of atmospheric water vapor and CO2 concentrations. Recent measurements made with a 2-micron coherent laser radar system, advances in the laser technology, and atmospheric propagation effects on 2-micron coherent lidar performance are described.

  10. Rock formation characterization for CO2-EOR and carbon geosequestration; 3D seismic amplitude and coherency anomalies, Wellington Field, Kansas, USA

    USGS Publications Warehouse

    Ohl, D.; Raef, A.; Watnef, L.; Bhattacharya, S.

    2011-01-01

    In this paper, we present a workflow for a Mississipian carbonates characterization case-study integrating post-stack seismic attributes, well-logs porosities, and seismic modeling to explore relating changes in small-scale "lithofacies" properties and/or sub-seismic resolution faulting to key amplitude and coherency 3D seismic attributes. The main objective of this study is to put emphasis on reservoir characterization that is both optimized for and subsequently benefiting from pilot tertiary CO2-EOR in preparation for future carbon geosequestration in a depleting reservoir and a deep saline aquifer. The extracted 3D seismic coherency attribute indicated anomalous features that can be interpreted as a lithofacies change or a sub-seismic resolution faulting. A 2D finite difference modeling has been undertaken to understand and potentially build discriminant attributes to map structural and/or lithofacies anomalies of interest especially when embarking upon CO2-EOR and/or carbon sequestration monitoring and management projects. ?? 2011 Society of Exploration Geophysicists.

  11. Tunable Single-Frequency Near IR Lasers for DIAL Applications

    NASA Technical Reports Server (NTRS)

    Henderson, Sammy W.; Marquardt, John H.; Carrig, Timothy J.; Gatt, Phil; Smith, Duane D.; Hale, Charley P.

    2000-01-01

    Tunable single-frequency sources in the 2-4 micron wavelength region are useful for remote DIAL measurements of chemicals and pollutants. We are developing tunable single-frequency transmitters and receivers for both direct and coherent detection lidar measurement applications. We have demonstrated a direct-diode-pumped PPLN-based OPO that operates single frequency, produces greater than 10 mW cw and is tunable over the 2.5 - 3.9 micron wavelength region. This laser has been used to injection seed a pulsed PPLN OPO, pumped by a 1.064 micron Nd:YAG laser, producing 50-100 microJoule single-frequency pulses at 100 Hz PRF near 3.6 micron wavelength. In addition, we have demonstrated a cw Cr:ZnSe laser that is tunable over the 2.1 - 2.8 micron wavelength region. This laser is pumped by a cw diode-pumped Tm:YALO laser and has produced over 1.8 W cw. Tm- and Tm, Ho-doped single-frequency solid-state lasers that produce over 50 mW cw and are tunable over approximately 10 nm in the 2 -2.1 micron band with fast PZT tuning have also been demonstrated. A fast PZT-tunable Tm, Ho:YLF laser was used for a direct-detection column content DIAL measurement of atmospheric CO2. Modeling shows that that all these cw and pulsed sources are useful for column-content coherent DIAL measurements at several km range using topographic targets.

  12. Tunable Single-Frequency Near IR Lasers for DIAL Applications

    NASA Technical Reports Server (NTRS)

    Henderson, Sammy W.; Marquardt, John H.; Carrig, Timothy J.; Gatt, Phil; Smith, Duane D.; Hale, Charley P.

    2000-01-01

    Tunable single-frequency sources in the 2-4 micron wavelength region are useful for remote DIAL measurements of chemicals and pollutants. We are developing tunable single-frequency transmitters and receivers for both direct and coherent detection lidar measurement applications. We have demonstrated a direct-diode-pumped PPLN-based OPO that operates single frequency, produces greater than 10 mW cw and is tunable over the 2.5 - 3.9 micron wavelength region. This laser has been used to injection seed a pulsed PPLN OPO, pumped by a 1.064 micron Nd:YAG laser, producing 50-100 microJoule single-frequency pulses at 100 Hz PRF near 3.6 micron wavelength. In addition, we have demonstrated a cw Cr:ZnSe laser that is tunable over the 2.1 - 2.8 micron wavelength region. This laser is pumped by a cw diode-pumped Tm:YALO laser and has produced over 1.8 W cw. Tm- and Tm, Ho-doped single-frequency solid-state lasers that produce over 50 mW cw and are tunable over approximately 10 nm in the 2 -2.1 micron band with fast PZT tuning have also been demonstrated. A fast PZT-tunable Tm, Ho:YLF laser was used for a direct-detection column content DIAL measurement of atmospheric CO2. Modeling shows that that all these cw and pulsed sources are useful for column-content coherent DIAL measurements at several km range using topographic targets.

  13. Investigation of acid-etched CO2 laser ablated enamel surfaces using polarization sensitive optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Nahm, Byung J.; Kang, Hobin; Chan, Kenneth; Fried, Daniel

    2012-01-01

    A carbon dioxide laser operating at the highly absorbed wavelength of 9.3μm with a pulse duration of 10-15μs is ideally suited for caries removal and caries prevention. The enamel thermally modified by the laser has enhanced resistance to acid dissolution. This is an obvious advantage for caries prevention; however, it is often necessary to etch the enamel surface to increase adhesion to composite restorative materials and such surfaces may be more resistant to etching. The purpose of the study was to non-destructively measure the susceptibility of laser-ablated enamel surfaces to acid dissolution before and after acid-etching using Polarization Sensitive Optical Coherence Tomography (PS-OCT). PS-OCT was used to acquire images of bovine enamel surfaces after exposure to laser irradiation at ablative fluence, acid-etching, and a surface softened dissolution model. The integrated reflectivity from lesion and the lesion depth were measured using PS-OCT. Samples were also sectioned for examination by Polarized Light Microscopy (PLM). PS-OCT images showed that acid-etching greatly accelerated the formation of subsurface lesions on both laser-irradiated and non-irradiated surfaces (P<0.05). A 37.5% phosphoric acid etch removed the laser modified enamel layer after 5-10 seconds.

  14. Definitive Dialing...Nursing Dial Access.

    ERIC Educational Resources Information Center

    Niles, Anne G.

    Nursing Dial Access, a taped library available by telephone to professional nurses in Wisconsin, was developed by the Department of Nursing Health Sciences Unit, University Extension, at the University of Wisconsin, under a grant from the Wisconsin Regional Medical Program. The program, available on an around-the-clock basis, provides short tapes…

  15. Differential Absorption Measurements of Atmospheric Water Vapor with a Coherent Lidar at 2050.532 nm

    NASA Technical Reports Server (NTRS)

    Koch, Grady J.; Dharamsi, Amin; Davis, Richard E.; Petros, Mulugeta; McCarthy, John C.

    1999-01-01

    Wind and water vapor are two major factors driving the Earth's atmospheric circulation, and direct measurement of these factors is needed for better understanding of basic atmospheric science, weather forecasting, and climate studies. Coherent lidar has proved to be a valuable tool for Doppler profiling of wind fields, and differential absorption lidar (DIAL) has shown its effectiveness in profiling water vapor. These two lidar techniques are generally considered distinctly different, but this paper explores an experimental combination of the Doppler and DIAL techniques for measuring both wind and water vapor with an eye-safe wavelength based on a solid-state laser material. Researchers have analyzed and demonstrated coherent DIAL water vapor measurements at 10 micrometers wavelength based on CO2 lasers. The hope of the research presented here is that the 2 gm wavelength in a holmium or thulium-based laser may offer smaller packaging and more rugged operation that the CO2-based approach. Researchers have extensively modeled 2 um coherent lasers for water vapor profiling, but no published demonstration is known. Studies have also been made, and results published on the Doppler portion, of a Nd:YAG-based coherent DIAL operating at 1.12 micrometers. Eye-safety of the 1.12 micrometer wavelength may be a concern, whereas the longer 2 micrometer and 10 micrometer systems allow a high level of eyesafety.

  16. Differential Absorption Measurements of Atmospheric Water Vapor with a Coherent Lidar at 2050.532 nm

    NASA Technical Reports Server (NTRS)

    Koch, Grady J.; Dharamsi, Amin; Davis, Richard E.; Petros, Mulugeta; McCarthy, John C.

    1999-01-01

    Wind and water vapor are two major factors driving the Earth's atmospheric circulation, and direct measurement of these factors is needed for better understanding of basic atmospheric science, weather forecasting, and climate studies. Coherent lidar has proved to be a valuable tool for Doppler profiling of wind fields, and differential absorption lidar (DIAL) has shown its effectiveness in profiling water vapor. These two lidar techniques are generally considered distinctly different, but this paper explores an experimental combination of the Doppler and DIAL techniques for measuring both wind and water vapor with an eye-safe wavelength based on a solid-state laser material. Researchers have analyzed and demonstrated coherent DIAL water vapor measurements at 10 micrometers wavelength based on CO2 lasers. The hope of the research presented here is that the 2 gm wavelength in a holmium or thulium-based laser may offer smaller packaging and more rugged operation that the CO2-based approach. Researchers have extensively modeled 2 um coherent lasers for water vapor profiling, but no published demonstration is known. Studies have also been made, and results published on the Doppler portion, of a Nd:YAG-based coherent DIAL operating at 1.12 micrometers. Eye-safety of the 1.12 micrometer wavelength may be a concern, whereas the longer 2 micrometer and 10 micrometer systems allow a high level of eyesafety.

  17. DialBetics

    PubMed Central

    Fujita, Hideo; Uchimura, Yuji; Omae, Koji; Aramaki, Eiji; Kato, Shigeko; Lee, Hanae; Kobayashi, Haruka; Kadowaki, Takashi; Ohe, Kazuhiko

    2014-01-01

    Numerous diabetes-management systems and programs for improving glycemic control to meet guideline targets have been proposed, using IT technology. But all of them allow only limited—or no—real-time interaction between patients and the system in terms of system response to patient input; few studies have effectively assessed the systems’ usability and feasibility to determine how well patients understand and can adopt the technology involved. DialBetics is composed of 4 modules: (1) data transmission module, (2) evaluation module, (3) communication module, and (4) dietary evaluation module. A 3-month randomized study was designed to assess the safety and usability of a remote health-data monitoring system, and especially its impact on modifying patient lifestyles to improve diabetes self-management and, thus, clinical outcomes. Fifty-four type 2 diabetes patients were randomly divided into 2 groups, 27 in the DialBetics group and 27 in the non-DialBetics control group. HbA1c and fasting blood sugar (FBS) values declined significantly in the DialBetics group: HbA1c decreased an average of 0.4% (from 7.1 ± 1.0% to 6.7 ± 0.7%) compared with an average increase of 0.1% in the non-DialBetics group (from 7.0 ± 0.9% to 7.1 ± 1.1%) (P = .015); The DialBetics group FBS decreased an average of 5.5 mg/dl compared with a non-DialBetics group average increase of 16.9 mg/dl (P = .019). BMI improvement—although not statistically significant because of the small sample size—was greater in the DialBetics group. DialBetics was shown to be a feasible and an effective tool for improving HbA1c by providing patients with real-time support based on their measurements and inputs. PMID:24876569

  18. Multiplex CARS for simultaneous measurement of temperature and CO(2) and H(2) concentrations in a combustion environment.

    PubMed

    Singh, J P; Yueh, F Y

    1991-05-20

    Simultaneous temperature and CO(2) concentration measurements with multiplex coherent anti-Stokes Raman scattering (CARS) spectra of CO(2) were performed. CARS spectra of pure CO(2) and various mixtures of CO(2) and N(2) in a furnace were recorded at various temperatures to test the computer code that simulates CO(2) CARS spectra using recent spectroscopic constants. The temperatures obtained from the CO(2) CARS spectra were in good agreement with thermocouple temperature measurements. However, the CO(2) concentrations cannot be accurately extracted from these spectra. It is believed by the authors that the cross-coherent effect, which has not been included in the present model, and the difficulty of accurately accounting for the background are two important factors affecting the CO(2) concentration measurements. H(2) pure rotational lines S(4) and S(5) were found in the CO(2) CARS spectra of a hydrocarbon flame. These assignments were confirmed from intensity ratio measurements of S(4) and S(5) lines at different temperatures. A theoretical study shows that the H(2) concentration measurement from the S(5) line should be more sensitive than that of the S(4) and S(9) lines at the flame temperature. CARS spectra of preanalyzed mixtures of N(2), CO(2), and H(2) in a furnace were recorded to investigate the feasibility of inferring the H(2) concentration from these spectra. Simultaneous CO(2) and H(2) multiplex CARS spectra were also recorded in a CH(4)/O(2) diffusion flame and in the MSU/DIAL test stand to observe the high temperature spectra. The results of these measurements are presented.

  19. FY05 FM Dial Summary Report

    SciTech Connect

    Harper, Warren W.; Strasburg, Jana D.; Golovich, Elizabeth C.; Thompson, Jason S.; Stewart, Timothy L.; Batdorf, Michael T.

    2005-12-01

    Pacific Northwest National Laboratory's Infrared Sensors team is focused on developing methods for standoff detection of nuclear proliferation. In FY05, PNNL continued the development of the FM DIAL (frequency-modulated differential absorption LIDAR) experiment. Additional improvements to the FM DIAL trailer provided greater stability during field campaigns which made it easier to explore new locations for field campaigns. In addition to the Hanford Townsite, successful experiments were conducted at the Marine Science Laboratory in Sequim, WA and the Nevada Test Site located outside Las Vegas, NV. The range of chemicals that can be detected by FM DIAL has also increased. Prior to FY05, distributed feedback quantum cascade lasers (DFB-QCL) were used in the FM DIAL experiments. With these lasers, only simple chemicals with narrow (1-2 cm-1) absorption spectra, such as CO2 and N2O, could be detected. Fabry-Perot (FP) QC lasers have much broader spectra (20-40 cm-1) which allows for the detection of larger chemicals and a wider array of chemicals that can be detected. A FP-QCL has been characterized and used during initial studies detecting DMMP (dimethyl methylphosphonate).

  20. IR DIAL performance modeling

    SciTech Connect

    Sharlemann, E.T.

    1994-07-01

    We are developing a DIAL performance model for CALIOPE at LLNL. The intent of the model is to provide quick and interactive parameter sensitivity calculations with immediate graphical output. A brief overview of the features of the performance model is given, along with an example of performance calculations for a non-CALIOPE application.

  1. Computer Simulation of Global Profiles of Carbon Dioxide Using a Pulsed, 2-Micron, Coherent-Detection, Column-Content DIAL System

    NASA Technical Reports Server (NTRS)

    Kavaya, Michael J.; Singh, Upendra N.; Koch, Grady J.; Yu, Jirong; Frehlich, Rod G.

    2009-01-01

    We present preliminary results of computer simulations of the error in measuring carbon dioxide mixing ratio profiles from earth orbit. The simulated sensor is a pulsed, 2-micron, coherent-detection lidar alternately operating on at least two wavelengths. The simulated geometry is a nadir viewing lidar measuring the column content signal. Atmospheric absorption is modeled using FASCODE3P software with the HITRAN 2004 absorption line data base. Lidar shot accumulation is employed up to the horizontal resolution limit. Horizontal resolutions of 50, 100, and 200 km are shown. Assuming a 400 km spacecraft orbit, the horizontal resolutions correspond to measurement times of about 7, 14, and 28 s. We simulate laser pulse-pair repetition frequencies from 1 Hz to 100 kHz. The range of shot accumulation is 7 to 2.8 million pulse-pairs. The resultant error is shown as a function of horizontal resolution, laser pulse-pair repetition frequency, and laser pulse energy. The effect of different on and off pulse energies is explored. The results are compared to simulation results of others and to demonstrated 2-micron operating points at NASA Langley.

  2. Dial-A-Cluster

    SciTech Connect

    Martin, Shawn; Quach, Tu-Toan

    2016-09-14

    Dial-A-Cluster is a web application that can be used to interactively analyze multi-variate time series data. It supports multiple users, DOE markings, and user authentication. It is designed to let the user adjust the influence of particular time series in the dataset, interact with the resulting dimension reduced visualization, interact with the time series themselves, and look for correlations of the data with any available meta-data.

  3. Radium dial workers

    SciTech Connect

    Rowland, R.E.; Lucas, H.F. Jr.

    1982-01-01

    The population of radium dial workers who were exposed to radium 30 to 50 years ago are currently being followed by the Center for Human Radiobiology at the Argonne National Laboratory. It is not clear that radium has induced additional malignancies in this population, other than the well-known bone sarcomas and head carcinomas, but elevated incidence rates for multiple myeloma and cancers of the colon, rectum, stomach, and breast suggest that radium might be involved. Continued follow-up of this population may resolve these questions. Finally, the question of the effect of fetal irradiation on the offspring of these women remains to be resolved. No evidence exists to suggest that any effects have occurred, but there is no question that a chronic irradiation of the developing fetus did take place. No formal follow-up of these children has yet been initiated.

  4. CO2-Neutral Fuels

    NASA Astrophysics Data System (ADS)

    Goede, Adelbert; van de Sanden, Richard

    2016-06-01

    Mimicking the biogeochemical cycle of System Earth, synthetic hydrocarbon fuels are produced from recycled CO2 and H2O powered by renewable energy. Recapturing CO2 after use closes the carbon cycle, rendering the fuel cycle CO2 neutral. Non-equilibrium molecular CO2 vibrations are key to high energy efficiency.

  5. Generation of continuously tunable 5 µm coherent radiation by second harmonic conversion of the emission of a multi-atmosphere TE CO2 laser in AgGaSe2

    NASA Astrophysics Data System (ADS)

    Padma Nilaya, J.; Saiprasad, M. B.; Biswas, D. J.

    2014-08-01

    Operation of a continuously tunable coherent source in the 5 micron region of the mid-infrared by frequency doubling of the continuously tunable emission of a multi-atmosphere TE CO2 laser in an AgGaSe2 crystal is reported. The performance has been characterized with regard to energy and power conversion efficiency as well as the threshold pump intensities at which the onset and termination of the second harmonic (S H) conversion process occurs. The absence of a gain switched peak in the emission of the pump laser that stemmed from its operation with a lean CO2 gas mixture enabled error-free threshold measurement for the onset of the S H generation process. Further, the excellent phase and amplitude synchronization of the SH emission with the pump pulse, that could be established by taking advantage of the rich modulation in the emission of the multimode pump laser in nanosecond time scale, bore experimental testimony to the instantaneous nature of the SH generation process.

  6. Advances in high-energy solid-state 2-micron laser transmitter development for ground and airborne wind and CO2 measurements

    NASA Astrophysics Data System (ADS)

    Singh, Upendra N.; Yu, Jirong; Petros, Mulugeta; Chen, Songsheng; Kavaya, Michael J.; Trieu, Bo; Bai, Yingxin; Petzar, Paul; Modlin, Edward A.; Koch, Grady; Beyon, Jeffrey

    2010-10-01

    Sustained research efforts at NASA Langley Research Center (LaRC) 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 resolution. The same laser, after a few modifications, can also be used in a Differential Absorption Lidar (DIAL) system for measuring atmospheric CO2 concentration profiles. Researchers at NASA Langley Research Center have developed a compact, flight capable, high energy, injection seeded, 2-micron laser transmitter for ground and airborne wind and carbon dioxide measurements. It is capable of producing 250 mJ at 10 Hz by an oscillator and one amplifier. This compact laser transmitter was integrated into a mobile trailer based coherent Doppler wind and CO2 DIAL system and was deployed during field measurement campaigns. This paper will give an overview of 2- micron solid-state laser technology development and discuss results from recent ground-based field measurements.

  7. Advances in High Energy Solid-State 2-micron Laser Transmitter Development for Ground and Airborne Wind and CO2 Measurements

    NASA Technical Reports Server (NTRS)

    Singh, Upendra N.; Yu, Jirong; Petros, Mulugeta; Chen, Songsheng; Kavaya, Michael J.; Trieu, Bo; Bai, Yingxin; Petzar, Paul; Modlin, Edward A.; Koch, Grady; hide

    2010-01-01

    Sustained research efforts at NASA Langley Research Center (LaRC) 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 resolution. The same laser, after a few modifications, can also be used in a Differential Absorption Lidar (DIAL) system for measuring atmospheric CO2 concentration profiles. Researchers at NASA Langley Research Center have developed a compact, flight capable, high energy, injection seeded, 2-micron laser transmitter for ground and airborne wind and carbon dioxide measurements. It is capable of producing 250 mJ at 10 Hz by an oscillator and one amplifier. This compact laser transmitter was integrated into a mobile trailer based coherent Doppler wind and CO2 DIAL system and was deployed during field measurement campaigns. This paper will give an overview of 2-micron solid-state laser technology development and discuss results from recent ground-based field measurements.

  8. CO2 -Responsive polymers.

    PubMed

    Lin, Shaojian; Theato, Patrick

    2013-07-25

    This Review focuses on the recent progress in the area of CO2 -responsive polymers and provides detailed descriptions of these existing examples. CO2 -responsive polymers can be categorized into three types based on their CO2 -responsive groups: amidine, amine, and carboxyl groups. Compared with traditional temperature, pH, or light stimuli-responsive polymers, CO2 -responsive polymers provide the advantage to use CO2 as a "green" trigger as well as to capture CO2 directly from air. In addition, the current challenges of CO2 -responsive polymers are discussed and the different solution methods are compared. Noteworthy, CO2 -responsive polymers are considered to have a prosperous future in various scientific areas.

  9. CO2 laser modeling

    NASA Technical Reports Server (NTRS)

    Johnson, Barry

    1992-01-01

    The topics covered include the following: (1) CO2 laser kinetics modeling; (2) gas lifetimes in pulsed CO2 lasers; (3) frequency chirp and laser pulse spectral analysis; (4) LAWS A' Design Study; and (5) discharge circuit components for LAWS. The appendices include LAWS Memos, computer modeling of pulsed CO2 lasers for lidar applications, discharge circuit considerations for pulsed CO2 lidars, and presentation made at the Code RC Review.

  10. Development of a 2-micron Pulsed Differential Absorption Lidar for Atmospheric CO2 Concentration Measurement by Direct Detection Technique

    NASA Astrophysics Data System (ADS)

    Yu, J.; Singh, U. N.; Petros, M.; Bai, Y.

    2011-12-01

    Researchers at NASA Langley Research Center are developing a 2-micron Pulsed Differential Absorption Lidar instrument for ground and airborne measurements via direct detection method. This instrument will provide an alternate approach to measure atmospheric CO2 concentrations with significant advantages. A high energy pulsed approach provides high-precision measurement capbility by having high signal-to-noise level and unambiguously eliminates the contamination from aerosols and clouds that can bias the IPDA measurement. A key component of the CO2 DIAL system, transceiver, is an existing, airborne ready, robust hardware which can provide 250mJ at 10Hz with double pulse format specifically designed for DIAL instrument. The exact wavelengths of the transceiver are controlled by well defined CW seed laser source to provide the required injection source for generating on-and-off line wavelength pulses sequentially. The compact, rugged, highly reliable transceiver is based on the unique Ho:Tm:YLF high-energy 2-micron pulsed laser technology. All the optical mounts are custom designed and have space heritage. They are designed to be adjustable and lockable and hardened to withstand vibrations that can occur in airborne operation. For the direct detection lidar application, a large primary mirror size is preferred. A 14 inch diameter telescope will be developed for this program. The CO2 DIAL/IPDA system requires many electronic functions to operate. These include diode, RF, seed laser, and PZT drivers; injection seeding detection and control; detector power supplies; and analog inputs to sample various sensors. Under NASA Laser Risk Reduction Program (LRRP), a control unit Compact Laser Electronics (CLE), is developed for the controlling the coherent wind lidar transceiver. Significant modifications and additions are needed to update it for CO2 lidar controls. The data acquisition system was built for ground CO2 measurement demonstration. The software will be updated for

  11. Field Testing of a Two-Micron DIAL System for Profiling Atmospheric Carbon Dioxide

    NASA Technical Reports Server (NTRS)

    Refaat, Tamer F.; Ismail, Syed; Koch, Grady J.; Diaz, Liza; Davis, Ken; Rubio, Manuel

    2010-01-01

    A 2-m DIAL system has been developed at NASA Langley Research Center through the NASA Instrument Incubator Program. The system utilizes a tunable 2-m pulsed laser and an IR phototransistor for the transmitter and the receiver, respectively. The system targets the CO2 absorption line R22 in the 2.05-m band. Field experiments were conducted at West Branch, Iowa, for evaluating the system for CO2 measurement by comparison with in-situ sensors. The CO2 in-situ sensors were located on the NOAA's WBI tower at 31, 99 and 379 m altitudes, besides the NOAA s aircraft was sampling at higher altitudes. Preliminary results demonstrated the capabilities of the DIAL system in profiling atmospheric CO2 using the 2-m wavelength. Results of these experiments will be presented and discussed.

  12. CO2 blood test

    MedlinePlus

    Bicarbonate test; HCO3-; Carbon dioxide test; TCO2; Total CO2; CO2 test - serum ... Many medicines can interfere with blood test results. Your health care provider will tell you if you need to stop taking any medicines before you have this test. DO ...

  13. CO2 laser resurfacing.

    PubMed

    Fitzpatrick, R E

    2001-07-01

    The CO2 Laser offers a variety of unique features in resurfacing facial photodamage and acne scarring. These include hemostasis, efficient removal of the epidermis in a single pass, thermally induced tissue tightening, and safe, predictable tissue interaction. Knowledge of these mechanisms will result in the capability of using the CO2 laser effectively and safely whether the goal is superficial or deep treatment.

  14. Proposal to Simultaneously Profile Wind and CO2 on Earth and Mars With 2-micron Pulsed Lidar Technologies

    NASA Technical Reports Server (NTRS)

    Singh, Upendra N.; Koch, Grady J.; Kavaya, Michael J.; Amzajerdian, Farzin; Ismail, Syed; Emmitt, David

    2005-01-01

    2-micron lidar technology has been in use and under continued improvement for many years toward wind measurements. But the 2-micron wavelength region is also rich in absorption lines of CO2 (and H2O to a lesser extent) that can be exploited with the differential absorption lidar (DIAL) technique to make species concentration measurements. A coherent detection receiver offers the possibility of making combined wind and DIAL measurements with wind derived from frequency shift of the backscatter spectrum and species concentration derived from power of the backscatter spectrum. A combined wind and CO2 measurement capability is of interest for applications on both Earth and Mars. CO2 measurements in the Earth atmosphere are of importance to studies of the global carbon cycle. Data on vertically-resolved CO2 profiles over large geographical observations areas are of particular interest that could potentially be made by deploying a lidar on an aircraft or satellite. By combining CO2 concentration with wind measurements an even more useful data product could be obtained in the calculation of CO2 flux. A challenge to lidar in this application is that CO2 concentration measurements must be made with a high level of precision and accuracy to better than 1%. The Martian atmosphere also presents wind and CO2 measurement problems that could be met with a combined DIAL/Doppler lidar. CO2 concentration in this scenario would be used to calculate atmospheric density since the Martian atmosphere is composed of 95% CO2. The lack of measurements of Mars atmospheric density in the 30-60 km range, dust storm formation and movements, and horizontal wind patterns in the 0-20 km range pose significant risks to aerocapture, and entry, descent, and landing of future robotic and human Mars missions. Systematic measurement of the Mars atmospheric density and winds will be required over several Mars years, supplemented with day-of-entry operational measurements. To date, there have been 5

  15. Proposal to Simultaneously Profile Wind and CO2 on Earth and Mars With 2-micron Pulsed Lidar Technologies

    NASA Technical Reports Server (NTRS)

    Singh, Upendra N.; Koch, Grady J.; Kavaya, Michael J.; Amzajerdian, Farzin; Ismail, Syed; Emmitt, David

    2005-01-01

    2-micron lidar technology has been in use and under continued improvement for many years toward wind measurements. But the 2-micron wavelength region is also rich in absorption lines of CO2 (and H2O to a lesser extent) that can be exploited with the differential absorption lidar (DIAL) technique to make species concentration measurements. A coherent detection receiver offers the possibility of making combined wind and DIAL measurements with wind derived from frequency shift of the backscatter spectrum and species concentration derived from power of the backscatter spectrum. A combined wind and CO2 measurement capability is of interest for applications on both Earth and Mars. CO2 measurements in the Earth atmosphere are of importance to studies of the global carbon cycle. Data on vertically-resolved CO2 profiles over large geographical observations areas are of particular interest that could potentially be made by deploying a lidar on an aircraft or satellite. By combining CO2 concentration with wind measurements an even more useful data product could be obtained in the calculation of CO2 flux. A challenge to lidar in this application is that CO2 concentration measurements must be made with a high level of precision and accuracy to better than 1%. The Martian atmosphere also presents wind and CO2 measurement problems that could be met with a combined DIAL/Doppler lidar. CO2 concentration in this scenario would be used to calculate atmospheric density since the Martian atmosphere is composed of 95% CO2. The lack of measurements of Mars atmospheric density in the 30-60 km range, dust storm formation and movements, and horizontal wind patterns in the 0-20 km range pose significant risks to aerocapture, and entry, descent, and landing of future robotic and human Mars missions. Systematic measurement of the Mars atmospheric density and winds will be required over several Mars years, supplemented with day-of-entry operational measurements. To date, there have been 5

  16. Development and Field Testing of a Continuously Operating CO2 Lidar Profiling System

    NASA Astrophysics Data System (ADS)

    Ismail, S.; Refaat, T.; Koch, G. J.; Davis, K.; Abedin, N. M.; Rubio, M. A.; Singh, U. N.

    2009-05-01

    A ground-based 2-micron DIAL system for profiling atmospheric CO2 was developed at NASA Langley Research Center (LaRC) under the NASA Instrument Incubator Program. This system leverages 2-micron laser technology developed under a number of NASA programs to develop new solid-state YLF laser technology that provides high pulse energy, tunable, wavelength-stabilized, and double-pulsed lasers that are operable over pre-selected temperature insensitive strong CO2 absorption lines suitable for profiling of lower tropospheric CO2. It also incorporates new high quantum efficiency, high gain, and relatively low noise phototransistors, and a new receiver/signal processor system to achieve high precision DIAL measurements. The DIAL system was integrated and tested at LaRC, and then incorporated in a field experiment for evaluation. The field experiment was conducted during June-July 2008, at West Branch, Iowa, which is located at the center of a domain rich in complementary CO2 measurements. The objective of the experiment was to evaluate the accuracy and precision of the system and its ability to distinguish contents between boundary layer and free troposphere. Therefore, the experiment was co-located with other CO2 measurement setups that aid the evaluation. These setups include NOAA WBI tower with in-situ CO2 sampling sensors at 31, 99 and 379 m altitudes; NOAA airborne CO2 profiling; and radiosondes for atmospheric temperature, pressure and relative humidity profiling at the site. The lidar operations included daytime CO2 measurements to sense the well-mixed atmospheric boundary layer and overlying troposphere; day-to-night and night-to-day transitions; and night observations to capture CO2 mixing ratio differences within the boundary layer. Measurements included atmospheric CO2 spatial and temporal profiles as well as column measurements using high altitude clouds. Examples of CO2 DIAL system capability and measurements from the field experiment will be presented.

  17. Outsourcing CO2 Emissions

    NASA Astrophysics Data System (ADS)

    Davis, S. J.; Caldeira, K. G.

    2009-12-01

    CO2 emissions from the burning of fossil fuels are the primary cause of global warming. Much attention has been focused on the CO2 directly emitted by each country, but relatively little attention has been paid to the amount of emissions associated with consumption of goods and services in each country. This consumption-based emissions inventory differs from the production-based inventory because of imports and exports of goods and services that, either directly or indirectly, involved CO2 emissions. Using the latest available data and reasonable assumptions regarding trans-shipment of embodied carbon through third-party countries, we developed a global consumption-based CO2 emissions inventory and have calculated associated consumption-based energy and carbon intensities. We find that, in 2004, 24% of CO2 emissions are effectively outsourced to other countries, with much of the developed world outsourcing CO2 emissions to emerging markets, principally China. Some wealthy countries, including Switzerland and Sweden, outsource over half of their consumption-based emissions, with many northern Europeans outsourcing more than three tons of emissions per person per year. The United States is both a big importer and exporter of emissions embodied in trade, outsourcing >2.6 tons of CO2 per person and at the same time as >2.0 tons of CO2 per person are outsourced to the United States. These large flows indicate that CO2 emissions embodied in trade must be taken into consideration when considering responsibility for increasing atmospheric greenhouse gas concentrations.

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

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  19. Synthetic Array Heterodyne Detection: Developments within the Caliope CO{sub 2} DIAL Program

    SciTech Connect

    Rehse, S.J.; Strauss, E.M.

    1995-09-01

    A new technique, Synthetic Array Heterodyne Detection, offers a wider field of view and improved signal to noise for coherent DIAL systems by reducing speckle interference. We have implemented a synthetic multi-pixel array using a CO{sub 2} laser on a single element HgCdTe photodiode.

  20. CO2-neutral fuels

    NASA Astrophysics Data System (ADS)

    Goede, A. P. H.

    2015-08-01

    The need for storage of renewable energy (RE) generated by photovoltaic, concentrated solar and wind arises from the fact that supply and demand are ill-matched both geographically and temporarily. This already causes problems of overcapacity and grid congestion in countries where the fraction of RE exceeds the 20% level. A system approach is needed, which focusses not only on the energy source, but includes conversion, storage, transport, distribution, use and, last but not least, the recycling of waste. Furthermore, there is a need for more flexibility in the energy system, rather than relying on electrification, integration with other energy systems, for example the gas network, would yield a system less vulnerable to failure and better adapted to requirements. For example, long-term large-scale storage of electrical energy is limited by capacity, yet needed to cover weekly to seasonal demand. This limitation can be overcome by coupling the electricity net to the gas system, considering the fact that the Dutch gas network alone has a storage capacity of 552 TWh, sufficient to cover the entire EU energy demand for over a month. This lecture explores energy storage in chemicals bonds. The focus is on chemicals other than hydrogen, taking advantage of the higher volumetric energy density of hydrocarbons, in this case methane, which has an approximate 3.5 times higher volumetric energy density. More importantly, it allows the ready use of existing gas infrastructure for energy storage, transport and distribution. Intermittent wind electricity generated is converted into synthetic methane, the Power to Gas (P2G) scheme, by splitting feedstock CO2 and H2O into synthesis gas, a mixture of CO and H2. Syngas plays a central role in the synthesis of a range of hydrocarbon products, including methane, diesel and dimethyl ether. The splitting is accomplished by innovative means; plasmolysis and high-temperature solid oxygen electrolysis. A CO2-neutral fuel cycle is

  1. Development of Double and Triple-Pulsed 2-micron IPDA Lidars for Column CO2 Measurements

    NASA Technical Reports Server (NTRS)

    Singh, Upendra N.; Yu, Jirong; Petros, Mulugeta; Refaat, Tamer F.; Remus, Ruben G.; Reithmaier, Karl

    2015-01-01

    Carbon dioxide (CO2) is an important greenhouse gas that significantly contributes to the carbon cycle and globalradiation budget on Earth. CO2 role on Earth’s climate is complicated due to different interactions with various climatecomponents that include the atmosphere, the biosphere and the hydrosphere. Although extensive worldwide efforts formonitoring atmospheric CO2 through various techniques, including in-situ and passive sensors, are taking place highuncertainties exist in quantifying CO2 sources and sinks. These uncertainties are mainly due to insufficient spatial andtemporal mapping of the gas. Therefore it is required to have more rapid and accurate CO2 monitoring with higheruniform coverage and higher resolution. CO2 DIAL operating in the 2-µm band offer better near-surface CO2measurement sensitivity due to the intrinsically stronger absorption lines. For more than 15 years, NASA LangleyResearch Center (LaRC) contributed in developing several 2-?m CO2 DIAL systems and technologies. This paperfocuses on the current development of the airborne double-pulsed and triple-pulsed 2-?m CO2 integrated pathdifferential absorption (IPDA) lidar system at NASA LaRC. This includes the IPDA system development andintegration. Results from ground and airborne CO2 IPDA testing will be presented. The potential of scaling suchtechnology to a space mission will be addressed.

  2. Assesment of dial data collection and analysis techniques

    NASA Technical Reports Server (NTRS)

    Browell, E. V.; Woods, P. T.

    1986-01-01

    The key issues in all areas of Differential Absorption Lidar (DIAL) data collection and analysis techniques were examined. This included consideration of the practical and theoretical limitations of DIAL and the range of possible DIAL measurements.

  3. Dial: A New Campus Information Access System

    ERIC Educational Resources Information Center

    Saffian, Steven R.

    1973-01-01

    The author describes a new campus communication system known as the Digital Information Access Line (DIAL) that disseminates taped information via telephone to students, staff, and faculty in the University Community. Dial access, a simple concept of educational technology, allows remote access at will to audio or visual material stored in a…

  4. Data and Information Access Link (DIAL)

    NASA Astrophysics Data System (ADS)

    Suresh, R.; Di, L.; McDonald, K.

    2001-05-01

    The Data and Information Access Link (DIAL) is a web based package of software tools for geospatial data storage, visualization and distribution. The DIAL software provides a web based easy to use software solution to small data producers to organize and distribute remote sensing data and metadata. DIAL system can handle heterogeneous types of remote sensing and field campaign data for Earth science applications. DIAL works with image data, grid, swath, and tabular, multidimensional array and point data. The DIAL system supports NASA's Earth Observing System and Data and Information System (EOSDIS) data standards HDF- EOS, Hierarchical Data Format (HDF), and network Common Data Format (netCDF). Data format translators are also available between HDF-EOS and Arc-Info, Geo-tiff, and shape formats. DIAL software works with data from the EOS Terra, LANDSAT 7, TRMM, SeaWiFS missions and many other types of legacy data from NASA. DIAL software is freely available for users. DIAL features: Catalog services: Spatial, temporal, and parameter-based search; Catalog search at inventory and directory levels; Automatic creation of metadata catalog; Supports ODBC/JDBC compatible databases for storing metadata/catalog; User-friendly Java search interface with query preview. Data services: On-line access to data and metadata; Single- and multi-granule subsetting and sub sampling based on array coordinates or record numbers; Single- and multi-granule sub setting and sub sampling based on geographic/map coordinates and physical parameters; Browse and dynamic/interactive visualization of data; Animation of time series or multi dimensional data; Interactive color composites of multi-spectral data; Overlay of coastal and political boundaries; On-line downloading of data in multiple formats; X-Y plotting for non-image data. DIAL can work as a standalone application or in a distributed environment. DIAL is integrated with NASA's Earth Science Data Gateway (EDG) providing support for the

  5. CO2 on Titan

    NASA Technical Reports Server (NTRS)

    Samuelson, R. E.; Maguire, W. C.; Hanel, R. A.; Kunde, V. G.; Jennings, D. E.; Yung, Y. L.; Aikin, A. C.

    1983-01-01

    A sharp stratospheric emission feature at 667/cm in the Voyager infrared spectra of Titan is associated with the nu2 Q branch of CO2. A coupling of photochemical and radiative-transfer theory yields an average mole fraction above the 110 mbar level of (1.5 + 1.5 or - 0.8) x 10 to the -9th, with most of the uncertainty being due to imprecise knowledge of the vertical distribution. CO2 is found to be in a steady state, with its abundance being regulated principally by the 72 K cold trap near the tropopause and secondarily by the rate at which water-bearing meteoritic material enters the top of the atmosphere. An influx of water about 0.4 times that at the top of the terrestrial atmosphere is consistent with a combination of the observed CO2 abundance and a steady-state CO mole fraction of 0.00011; the thoeretical value for CO is close to the value observed by Lutz et al. (1983), although there are large margins for error in both numbers. If steady-state conditions for CO prevail, little information is available regarding the evolution of Titan's atmosphere.

  6. Advanced 2-micron Solid-state Laser for Wind and CO2 Lidar Applications

    NASA Technical Reports Server (NTRS)

    Yu, Jirong; Trieu, Bo C.; Petros, Mulugeta; Bai, Yingxin; Petzar, Paul J.; Koch, Grady J.; Singh, Upendra N.; Kavaya, Michael J.

    2006-01-01

    Significant advancements in the 2-micron laser development have been made recently. Solid-state 2-micron laser is a key subsystem for a coherent Doppler lidar that measures the horizontal and vertical wind velocities with high precision and resolution. The same laser, after a few modifications, can also be used in a Differential Absorption Lidar (DIAL) system for measuring atmospheric CO2 concentration profiles. The world record 2-micron laser energy is demonstrated with an oscillator and two amplifiers system. It generates more than one joule per pulse energy with excellent beam quality. Based on the successful demonstration of a fully conductive cooled oscillator by using heat pipe technology, an improved fully conductively cooled 2-micron amplifier was designed, manufactured and integrated. It virtually eliminates the running coolant to increase the overall system efficiency and reliability. In addition to technology development and demonstration, a compact and engineering hardened 2-micron laser is under development. It is capable of producing 250 mJ at 10 Hz by an oscillator and one amplifier. This compact laser is expected to be integrated to a lidar system and take field measurements. The recent achievements push forward the readiness of such a laser system for space lidar applications. This paper will review the developments of the state-of-the-art solid-state 2-micron laser.

  7. CO2 laser preionisation

    NASA Technical Reports Server (NTRS)

    Spiers, Gary D.

    1991-01-01

    The final report for work done during the reporting period of January 25, 1990 to January 24, 1991 is presented. A literature survey was conducted to identify the required parameters for effective preionization in TEA CO2 lasers and the methods and techniques for characterizing preionizers are reviewed. A numerical model of the LP-140 cavity was used to determine the cause of the transverse mode stability improvement obtained when the cavity was lengthened. The measurement of the voltage and current discharge pulses on the LP-140 were obtained and their subsequent analysis resulted in an explanation for the low efficiency of the laser. An assortment of items relating to the development of high-voltage power supplies is also provided. A program for analyzing the frequency chirp data files obtained with the HP time and frequency analyzer is included. A program to calculate the theoretical LIMP chirp is also included and a comparison between experiment and theory is made. A program for calculating the CO2 linewidth and its dependence on gas composition and pressure is presented. The program also calculates the number of axial modes under the FWHM of the line for a given resonator length. A graphical plot of the results is plotted.

  8. CO2 pulses

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    Studies of the sources and the increases of carbon dioxide in the atmosphere have been both frustrating and alarming; frustrating because so little is known and alarming because the potential consequences could be so grave (Eos, November 15, 1983, p. 929). The nature of the complexities have recently been focused upon by studies of the carbon cycle at the earth's surface and its influence on the atmosphere. It turns out that most of the increases of atmospheric carbon dioxide are from two sources: (1) petroleum and coal use and (2) the clearing of major forested lands.It is generally acknowledged that fossil fuel use has declined sharply during the past several years and that the deforestation of large areas under development will end. A recent review of current thinking on the effects of global deforestation by G.M. Woodwell and others stated that, “appropriate action taken now might reduce or eliminate the problem. Stabilization of the rate of combustion of fossil fuels combined with a program of reforestation would contribute toward stabilizing the CO2 content of the atmosphere … we need not accept as inexorable a global warming due to the accumulation of CO2 in the atmosphere” (Science, 222, 1081-1086, 1983).

  9. Direct measurements of collisionally broadened Raman linewidths of CO2 S-branch transitions.

    PubMed

    Roy, Sukesh; Hsu, Paul S; Jiang, Naibo; Gord, Joseph R; Kulatilaka, Waruna D; Stauffer, Hans U; Gord, James R

    2013-01-14

    We report direct measurements of S-branch Raman-coherence lifetimes of CO(2) resulting from CO(2)-CO(2) and CO(2)-N(2) collisions by employing time-resolved picosecond coherent anti-Stokes Raman scattering spectroscopy. The S-branch (ΔJ = +2) transitions of CO(2) with rotational quantum number J = 0-52 were simultaneously excited using a broadband (~5 nm) laser pulse with a full-width-at-half-maximum duration of ~115 ps. The coherence lifetimes of CO(2) for a pressure range of 0.05-1 atm were measured directly by probing the rotational coherence with a nearly transform-limited, 90-ps-long laser pulse. These directly measured Raman-coherence lifetimes, when converted to collisional linewidth broadening coefficients, differ from the previously reported broadening coefficients extracted from frequency-domain rotational Raman and infrared-absorption spectra and from theoretical calculations by 7%-25%.

  10. Combined 2-micron Dial and Doppler Lidar: Application to the Atmosphere of Earth or Mars

    NASA Technical Reports Server (NTRS)

    Singh, Upendra N.; Koch, Grady J.; Ismail, Syed; Kavaya, Michael; Yu, Jirong; Wood, Sidney A.; Emmitt, G. David

    2006-01-01

    A concept is explored for combining the Doppler and DIAL techniques into a single, multifunctional instrument. Wind, CO2 concentration, and aerosol density can all be measured. Technology to build this instrument is described, including the demonstration of a prototype lidar. Applications are described for use in the Earth science. The atmosphere of Mars can also be studied, and results from a recently-developed simulation model of performance in the Martian atmosphere are presented.

  11. On-Line Wavelength Calibration of Pulsed Laser for CO2 Differential Absorption LIDAR

    NASA Astrophysics Data System (ADS)

    Xiang, Chengzhi; Ma, Xin; Han, Ge; Liang, Ailin; Gong, Wei

    2016-06-01

    Differential absorption lidar (DIAL) remote sensing is a promising technology for atmospheric CO2 detection. However, stringent wavelength accuracy and stability are required in DIAL system. Accurate on-line wavelength calibration is a crucial procedure for retrieving atmospheric CO2 concentration using the DIAL, particularly when pulsed lasers are adopted in the system. Large fluctuations in the intensities of a pulsed laser pose a great challenge for accurate on-line wavelength calibration. In this paper, a wavelength calibration strategy based on multi-wavelength scanning (MWS) was proposed for accurate on-line wavelength calibration of a pulsed laser for CO2 detection. The MWS conducted segmented sampling across the CO2 absorption line with appropriate number of points and range of widths by using a tunable laser. Complete absorption line of CO2 can be obtained through a curve fitting. Then, the on-line wavelength can be easily found at the peak of the absorption line. Furthermore, another algorithm called the energy matching was introduced in the MWS to eliminate the backlash error of tunable lasers during the process of on-line wavelength calibration. Finally, a series of tests was conducted to elevate the calibration precision of MWS. Analysis of tests demonstrated that the MWS proposed in this paper could calibrate the on-line wavelength of pulsed laser accurately and steadily.

  12. CO2 Laser Market

    NASA Astrophysics Data System (ADS)

    Simonsson, Samuel

    1989-03-01

    It gives me a great deal of pleasure to introduce our final speaker of this morning's session for two reasons: First of all, his company has been very much in the news not only in our own community but in the pages of Wall Street Journal and in the world economic press. And, secondly, we would like to welcome him to our shores. He is a temporary resident of the United States, for a few months, forsaking his home in Germany to come here and help with the start up of a new company which we believe, probably, ranks #1 as the world supplier of CO2 lasers now, through the combination of former Spectra Physics Industrial Laser Division and Rofin-Sinar GMBH. Samuel Simonsson is the Chairman of the Board of Rofin-Sinar, Inc., here in the U.S. and managing director of Rofin-Sinar GMBH. It is a pleasure to welcome him.

  13. Laser-induced plasma shutter for infra red range-resolved DIAL

    NASA Astrophysics Data System (ADS)

    Gasmi, Taieb; Gasmi, Khaled

    2012-10-01

    The pulse from a transversely excited atmospheric CO2 laser consists of a sharp spike followed by a long, drawn out tail region spanning about 2-5 μs caused by the nitrogen gas in the laser cavity. The nitrogen tail is undesirable in many applications because it decreases the average power of the laser pulse. High stability and energy-efficient laser-induced plasma shutter to clip the nitrogen tail of CO2-TEA based DIAL is built. Optimum shutter gases pressures and laser breakdown intensities are reported. Clipped laser pulses are also field tested.

  14. Development of a Pulsed 2-micron Laser Transmitter for CO2 Sensing from Space

    NASA Technical Reports Server (NTRS)

    Singh, Upendra N.; Yu, Jirong; Bai, Yingxin; Petros, Mulugeta; Menzies, Robert T.

    2011-01-01

    NASA Langley Research Center (LaRC), in collaboration with NASA Jet Propulsion Laboratory (JPL), is engaged in the development and demonstration of a highly efficient, versatile, 2-micron pulsed laser that can be used in a pulsed Differential Absorption Lidar (DIAL)/Integrated Path Differential Absorption (IPDA) instrument to make precise, high-resolution CO2 measurements to investigate sources, sinks, and fluxes of CO2. This laser transmitter will feature performance characteristics needed for an ASCENDS system that will be capable of delivering the CO2 measurement precision required by the Earth Science Decadal Survey (DS).

  15. Forecasting global atmospheric CO2

    NASA Astrophysics Data System (ADS)

    Agustí-Panareda, A.; Massart, S.; Chevallier, F.; Boussetta, S.; Balsamo, G.; Beljaars, A.; Ciais, P.; Deutscher, N. M.; Engelen, R.; Jones, L.; Kivi, R.; Paris, J.-D.; Peuch, V.-H.; Sherlock, V.; Vermeulen, A. T.; Wennberg, P. O.; Wunch, D.

    2014-11-01

    A new global atmospheric carbon dioxide (CO2) real-time forecast is now available as part of the pre-operational Monitoring of Atmospheric Composition and Climate - Interim Implementation (MACC-II) service using the infrastructure of the European Centre for Medium-Range Weather Forecasts (ECMWF) Integrated Forecasting System (IFS). One of the strengths of the CO2 forecasting system is that the land surface, including vegetation CO2 fluxes, is modelled online within the IFS. Other CO2 fluxes are prescribed from inventories and from off-line statistical and physical models. The CO2 forecast also benefits from the transport modelling from a state-of-the-art numerical weather prediction (NWP) system initialized daily with a wealth of meteorological observations. This paper describes the capability of the forecast in modelling the variability of CO2 on different temporal and spatial scales compared to observations. The modulation of the amplitude of the CO2 diurnal cycle by near-surface winds and boundary layer height is generally well represented in the forecast. The CO2 forecast also has high skill in simulating day-to-day synoptic variability. In the atmospheric boundary layer, this skill is significantly enhanced by modelling the day-to-day variability of the CO2 fluxes from vegetation compared to using equivalent monthly mean fluxes with a diurnal cycle. However, biases in the modelled CO2 fluxes also lead to accumulating errors in the CO2 forecast. These biases vary with season with an underestimation of the amplitude of the seasonal cycle both for the CO2 fluxes compared to total optimized fluxes and the atmospheric CO2 compared to observations. The largest biases in the atmospheric CO2 forecast are found in spring, corresponding to the onset of the growing season in the Northern Hemisphere. In the future, the forecast will be re-initialized regularly with atmospheric CO2 analyses based on the assimilation of CO2 products retrieved from satellite measurements and

  16. 48 cases of the lower lid transconjunctival belpharoplastry with ultrapulse CO2 laser

    NASA Astrophysics Data System (ADS)

    Lin, Xiao-Hua; Wu, Hui-Zhen

    1998-11-01

    There are 48 cases on the lower lid transconjunctival belpharoplastry with ultrapulse CO2 laser produced by American Coherent Company. Compared the result, we concluded it is better to incise the tissue with the ultrapulse CO2 laser than that with the continue-wave CO2 laser. The former can prevent granulation tissue over growing in the wound and improve wound healing.

  17. Forecasting global atmospheric CO2

    NASA Astrophysics Data System (ADS)

    Agustí-Panareda, A.; Massart, S.; Chevallier, F.; Boussetta, S.; Balsamo, G.; Beljaars, A.; Ciais, P.; Deutscher, N. M.; Engelen, R.; Jones, L.; Kivi, R.; Paris, J.-D.; Peuch, V.-H.; Sherlock, V.; Vermeulen, A. T.; Wennberg, P. O.; Wunch, D.

    2014-05-01

    A new global atmospheric carbon dioxide (CO2) real-time forecast is now available as part of the pre-operational Monitoring of Atmospheric Composition and Climate - Interim Implementation (MACC-II) service using the infrastructure of the European Centre for Medium-Range Weather Forecasts (ECMWF) Integrated Forecasting System (IFS). One of the strengths of the CO2 forecasting system is that the land surface, including vegetation CO2 fluxes, is modelled online within the IFS. Other CO2 fluxes are prescribed from inventories and from off-line statistical and physical models. The CO2 forecast also benefits from the transport modelling from a state-of-the-art numerical weather prediction (NWP) system initialized daily with a wealth of meteorological observations. This paper describes the capability of the forecast in modelling the variability of CO2 on different temporal and spatial scales compared to observations. The modulation of the amplitude of the CO2 diurnal cycle by near-surface winds and boundary layer height is generally well represented in the forecast. The CO2 forecast also has high skill in simulating day-to-day synoptic variability. In the atmospheric boundary layer, this skill is significantly enhanced by modelling the day-to-day variability of the CO2 fluxes from vegetation compared to using equivalent monthly mean fluxes with a diurnal cycle. However, biases in the modelled CO2 fluxes also lead to accumulating errors in the CO2 forecast. These biases vary with season with an underestimation of the amplitude of the seasonal cycle both for the CO2 fluxes compared to total optimized fluxes and the atmospheric CO2 compared to observations. The largest biases in the atmospheric CO2 forecast are found in spring, corresponding to the onset of the growing season in the Northern Hemisphere. In the future, the forecast will be re-initialized regularly with atmospheric CO2 analyses based on the assimilation of CO2 satellite retrievals, as they become available in

  18. Optimization of A 2-Micron Laser Frequency Stabilization System for a Double-Pulse CO2 Differential Absorption Lidar

    NASA Technical Reports Server (NTRS)

    Chen, Songsheng; Yu, Jirong; Bai, Yingsin; Koch, Grady; Petros, Mulugeta; Trieu, Bo; Petzar, Paul; Singh, Upendra N.; Kavaya, Michael J.; Beyon, Jeffrey

    2010-01-01

    A carbon dioxide (CO2) Differential Absorption Lidar (DIAL) for accurate CO2 concentration measurement requires a frequency locking system to achieve high frequency locking precision and stability. We describe the frequency locking system utilizing Frequency Modulation (FM), Phase Sensitive Detection (PSD), and Proportional Integration Derivative (PID) feedback servo loop, and report the optimization of the sensitivity of the system for the feed back loop based on the characteristics of a variable path-length CO2 gas cell. The CO2 gas cell is characterized with HITRAN database (2004). The method can be applied for any other frequency locking systems referring to gas absorption line.

  19. Co2 geological sequestration

    SciTech Connect

    Xu, Tianfu

    2004-11-18

    Human activities are increasingly altering the Earth's climate. A particular concern is that atmospheric concentrations of carbon dioxide (CO{sub 2}) may be rising fast because of increased industrialization. CO{sub 2} is a so-called ''greenhouse gas'' that traps infrared radiation and may contribute to global warming. Scientists project that greenhouse gases such as CO{sub 2} will make the arctic warmer, which would melt glaciers and raise sea levels. Evidence suggests that climate change may already have begun to affect ecosystems and wildlife around the world. Some animal species are moving from one habitat to another to adapt to warmer temperatures. Future warming is likely to exceed the ability of many species to migrate or adjust. Human production of CO{sub 2} from fossil fuels (such as at coal-fired power plants) is not likely to slow down soon. It is urgent to find somewhere besides the atmosphere to put these increased levels of CO{sub 2}. Sequestration in the ocean and in soils and forests are possibilities, but another option, sequestration in geological formations, may also be an important solution. Such formations could include depleted oil and gas reservoirs, unmineable coal seams, and deep saline aquifers. In many cases, injection of CO2 into a geological formation can enhance the recovery of hydrocarbons, providing value-added byproducts that can offset the cost of CO{sub 2} capture and sequestration. Before CO{sub 2} gas can be sequestered from power plants and other point sources, it must be captured. CO{sub 2} is also routinely separated and captured as a by-product from industrial processes such as synthetic ammonia production, H{sub 2} production, and limestone calcination. Then CO{sub 2} must be compressed into liquid form and transported to the geological sequestration site. Many power plants and other large emitters of CO{sub 2} are located near geological formations that are amenable to CO{sub 2} sequestration.

  20. India Co2 Emissions

    NASA Astrophysics Data System (ADS)

    Sharan, S.; Diffenbaugh, N. S.

    2010-12-01

    created a balance in between the “developed” and developing countries. If India was producing the same amounts of emissions per capita as the it would have a total of 20 billion metric tons of CO2 emissions annually.

  1. Is CO2 ice permanent?

    NASA Technical Reports Server (NTRS)

    Lindner, Bernhard Lee

    1992-01-01

    Carbon dioxide ice has been inferred to exist at the south pole in summertime, but Earth based measurements in 1969 of water vapor in the Martian atmosphere suggest that all CO2 ice sublined from the southern polar cap and exposed underlying water ice. This implies that the observed summertime CO2 ice is of recent origin. It appears possible to construct an energy balance model that maintains seasonal CO2 ice at the south pole year round and still reasonably simulates the polar cap regression and atmospheric pressure data. This implies that the CO2 ice observed in the summertime south polar cap could be seasonal in origin, and that minor changes in climate could cause CO2 ice to completely vanish, as would appear to have happened in 1969. However, further research remains before it is certain whether the CO2 ice observed in the summertime south polar cap is seasonal or is part of a permanent reservoir.

  2. Coherent IR radar technology

    NASA Astrophysics Data System (ADS)

    Gschwendtner, A. B.; Harney, R. C.; Hull, R. J.

    Recent progress in the development of coherent IR radar equipment is reviewed, focusing on the Firepond laser radar installation and the more compact systems derived for it. The design and capabilities of Firepond as a long-range satellite-tracking device are outlined. The technological improvements necessary to make laser radar mobile are discussed: a lightweight, stable 5-10-W transmitter laser for both CW and pulsed operation, a 12-element HgCdTe detector array, an eccentric-pupil Ritchey-Chretien telescope, and a combination of near-field phase modification and anamorphic expansion to produce a fan beam of relatively uniform intensity. Sample images obtained with a prototype system are shown, and the applicability of the mobile system to range-resolved coherent DIAL measurement is found to be similar to that of a baseline DIAL system.

  3. Collisional broadening of CO2 IR lines. II. Calculations

    NASA Astrophysics Data System (ADS)

    Rosenmann, L.; Hartmann, J. M.; Perrin, M. Y.; Taine, J.

    1988-03-01

    The ability of available theoretical models in describing broadening mechanisms is tested for the CO2-O2, CO2-CO2, and CO2-N2 systems. It is shown that the Anderson-Tsao-Curnutte theory is inaccurate since short-range forces can contribute significantly to broadening. We use the approach of Robert and Bonamy, but the usual expansion of the atom-atom potential to the fourth order around the intermolecular distance appears insufficient at short distances for these particular systems. We propose a better representation of the radial dependence of the atom-atom potential, while keeping the previous analytical expression of the cross section. Satisfactory results are obtained for both the rotational quantum number dependence of room-temperature CO2-O2, CO2-CO2, and CO2-N2 half-widths and the evolution of CO2-N2 broadening with temperature. It is shown that the isotropic part of the potential involved in the trajectory calculation must be coherently deduced from the atom-atom interaction potential.

  4. Advanced Atmospheric Water Vapor DIAL Detection System

    NASA Technical Reports Server (NTRS)

    Refaat, Tamer F.; Elsayed-Ali, Hani E.; DeYoung, Russell J. (Technical Monitor)

    2000-01-01

    Measurement of atmospheric water vapor is very important for understanding the Earth's climate and water cycle. The remote sensing Differential Absorption Lidar (DIAL) technique is a powerful method to perform such measurement from aircraft and space. This thesis describes a new advanced detection system, which incorporates major improvements regarding sensitivity and size. These improvements include a low noise advanced avalanche photodiode detector, a custom analog circuit, a 14-bit digitizer, a microcontroller for on board averaging and finally a fast computer interface. This thesis describes the design and validation of this new water vapor DIAL detection system which was integrated onto a small Printed Circuit Board (PCB) with minimal weight and power consumption. Comparing its measurements to an existing DIAL system for aerosol and water vapor profiling validated the detection system.

  5. Mid-wave infrared DIAL noise phenomenology

    SciTech Connect

    Magnotta, F., Morris, J.R., Neuman, W.A., Scharlemann, E.T.

    1997-07-23

    LLNL has utilized optical parametric oscillator technology to develop and field a rapidly-tunable mid-wave infrared (MWIR) DIAL system. The system can be tuned at up to 1 KHz over the 3.3-3.8 micron spectral region, where hydrogen-bond stretching modes provide spectroscopic signatures for a wide variety of chemicals. We have fielded the DIAL system on the LLNL site with targets at horizontal ranges of up to 2 km. We have collected data on noise levels and correlations and their dependences on range, turbulence, and receiver aperture size. In this paper we describe some of the implications of this data for MWIR DIAL phenomenology. In particular, the interplay of turbulence and speckle to produce the observed noise fluctuations at short ranges (<500 m) is presented.

  6. CO2 interaction with geomaterials.

    SciTech Connect

    Guthrie, George D.; Al-Saidi, Wissam A.; Jordan, Kenneth D.; Voora, Vamsee, K.; Romanov, Vyacheslav N.; Lopano, Christina L; Myshakin, Eugene M.; Hur, Tae Bong; Warzinski, Robert P.; Lynn, Ronald J.; Howard, Bret H.; Cygan, Randall Timothy

    2010-09-01

    This work compares the sorption and swelling processes associated with CO2-coal and CO2-clay interactions. We investigated the mechanisms of interaction related to CO2 adsortion in micropores, intercalation into sub-micropores, dissolution in solid matrix, the role of water, and the associated changes in reservoir permeability, for applications in CO2 sequestration and enhanced coal bed methane recovery. The structural changes caused by CO2 have been investigated. A high-pressure micro-dilatometer was equipped to investigate the effect of CO2 pressure on the thermoplastic properties of coal. Using an identical dilatometer, Rashid Khan (1985) performed experiments with CO2 that revealed a dramatic reduction in the softening temperature of coal when exposed to high-pressure CO2. A set of experiments was designed for -20+45-mesh samples of Argonne Premium Pocahontas No.3 coal, which is similar in proximate and ultimate analysis to the Lower Kittanning seam coal that Khan used in his experiments. No dramatic decrease in coal softening temperature has been observed in high-pressure CO2 that would corroborate the prior work of Khan. Thus, conventional polymer (or 'geopolymer') theories may not be directly applicable to CO2 interaction with coals. Clays are similar to coals in that they represent abundant geomaterials with well-developed microporous structure. We evaluated the CO2 sequestration potential of clays relative to coals and investigated the factors that affect the sorption capacity, rates, and permanence of CO2 trapping. For the geomaterials comparison studies, we used source clay samples from The Clay Minerals Society. Preliminary results showed that expandable clays have CO2 sorption capacities comparable to those of coal. We analyzed sorption isotherms, XRD, DRIFTS (infrared reflectance spectra at non-ambient conditions), and TGA-MS (thermal gravimetric analysis) data to compare the effects of various factors on CO2 trapping. In montmorillonite, CO2

  7. A Preliminary Study of CO2 Flux Measurements by Lidar

    NASA Technical Reports Server (NTRS)

    Gibert, Fabien; Koch, Grady J.; Beyon, Jeffrey Y.; Hilton, T.; Davis, Kenneth J.; Andrews, Arlyn; Ismail, Syed; Singh, Upendra N.

    2008-01-01

    A mechanistic understanding of the global carbon cycle requires quantification of terrestrial ecosystem CO2 fluxes at regional scales. In this paper, we analyze the potential of a Doppler DIAL system to make flux measurements of atmospheric CO2 using the eddy-covariance and boundary layer budget methods and present results from a ground based experiment. The goal of this study is to put CO2 flux point measurements in a mesoscale context. In June 2007, a field experiment combining a 2-m Doppler Heterodyne Differential Absorption Lidar (HDIAL) and in-situ sensors of a 447-m tall tower (WLEF) took place in Wisconsin. The HDIAL measures simultaneously: 1) CO2 mixing ratio, 2) atmosphere structure via aerosol backscatter and 3) radial velocity. We demonstrate how to synthesize these data into regional flux estimates. Lidar-inferred fluxes are compared with eddy-covariance fluxes obtained in-situ at 396m AGL from the tower. In cases where the lidar was not yet able to measure the fluxes with acceptable precision, we discuss possible modifications to improve system performance.

  8. Leaves: Elevated CO2 levels

    USDA-ARS?s Scientific Manuscript database

    Burning fossil fuels and land use changes such as deforestation and urbanization have led to a dramatic rise in the concentration of carbon dioxide (CO2) in the atmosphere since the onset of the Industrial Revolution. The highly dilute CO2 from the atmosphere enters plant leaves where it is concentr...

  9. CO2 Sequestration short course

    SciTech Connect

    DePaolo, Donald J.; Cole, David R; Navrotsky, Alexandra; Bourg, Ian C

    2014-12-08

    Given the public’s interest and concern over the impact of atmospheric greenhouse gases (GHGs) on global warming and related climate change patterns, the course is a timely discussion of the underlying geochemical and mineralogical processes associated with gas-water-mineral-interactions encountered during geological sequestration of CO2. The geochemical and mineralogical processes encountered in the subsurface during storage of CO2 will play an important role in facilitating the isolation of anthropogenic CO2 in the subsurface for thousands of years, thus moderating rapid increases in concentrations of atmospheric CO2 and mitigating global warming. Successful implementation of a variety of geological sequestration scenarios will be dependent on our ability to accurately predict, monitor and verify the behavior of CO2 in the subsurface. The course was proposed to and accepted by the Mineralogical Society of America (MSA) and The Geochemical Society (GS).

  10. Development of tunable high pressure CO2 laser for lidar measurements of pollutants and wind velocities

    NASA Technical Reports Server (NTRS)

    Levine, J. S.; Guerra, M.; Javan, A.

    1980-01-01

    The problem of laser energy extraction at a tunable monochromatic frequency from an energetic high pressure CO2 pulsed laser plasma, for application to remote sensing of atmospheric pollutants by Differential Absorption Lidar (DIAL) and of wind velocities by Doppler Lidar, was investigated. The energy extraction principle analyzed is based on transient injection locking (TIL) at a tunable frequency. Several critical experiments for high gain power amplification by TIL are presented.

  11. 47 CFR 51.207 - Local dialing parity.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 3 2013-10-01 2013-10-01 false Local dialing parity. 51.207 Section 51.207... Obligations of All Local Exchange Carriers § 51.207 Local dialing parity. A LEC shall permit telephone exchange service customers within a local calling area to dial the same number of digits to make a local...

  12. 47 CFR 51.213 - Toll dialing parity implementation plans.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 3 2013-10-01 2013-10-01 false Toll dialing parity implementation plans. 51... parity implementation plans. (a) A LEC must file a plan for providing intraLATA toll dialing parity... dialing parity within a state until the implementation plan has been approved by the appropriate...

  13. 47 CFR 51.205 - Dialing parity: General.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 3 2012-10-01 2012-10-01 false Dialing parity: General. 51.205 Section 51.205... Obligations of All Local Exchange Carriers § 51.205 Dialing parity: General. A local exchange carrier (LEC) shall provide local and toll dialing parity to competing providers of telephone exchange service...

  14. 47 CFR 51.209 - Toll dialing parity.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Toll dialing parity. 51.209 Section 51.209... Obligations of All Local Exchange Carriers § 51.209 Toll dialing parity. (a) A LEC shall implement throughout each state in which it offers telephone exchange service intraLATA and interLATA toll dialing...

  15. 47 CFR 51.213 - Toll dialing parity implementation plans.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 3 2014-10-01 2014-10-01 false Toll dialing parity implementation plans. 51... parity implementation plans. (a) A LEC must file a plan for providing intraLATA toll dialing parity... dialing parity within a state until the implementation plan has been approved by the appropriate...

  16. 47 CFR 51.213 - Toll dialing parity implementation plans.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Toll dialing parity implementation plans. 51... parity implementation plans. (a) A LEC must file a plan for providing intraLATA toll dialing parity... dialing parity within a state until the implementation plan has been approved by the appropriate...

  17. 47 CFR 51.215 - Dialing parity: Cost recovery.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 3 2013-10-01 2013-10-01 false Dialing parity: Cost recovery. 51.215 Section... (CONTINUED) INTERCONNECTION Obligations of All Local Exchange Carriers § 51.215 Dialing parity: Cost recovery. (a) A LEC may recover the incremental costs necessary for the implementation of toll dialing...

  18. 47 CFR 51.209 - Toll dialing parity.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 3 2012-10-01 2012-10-01 false Toll dialing parity. 51.209 Section 51.209... Obligations of All Local Exchange Carriers § 51.209 Toll dialing parity. (a) A LEC shall implement throughout each state in which it offers telephone exchange service intraLATA and interLATA toll dialing...

  19. 47 CFR 51.213 - Toll dialing parity implementation plans.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 3 2012-10-01 2012-10-01 false Toll dialing parity implementation plans. 51... parity implementation plans. (a) A LEC must file a plan for providing intraLATA toll dialing parity... dialing parity within a state until the implementation plan has been approved by the appropriate...

  20. 47 CFR 51.209 - Toll dialing parity.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 3 2013-10-01 2013-10-01 false Toll dialing parity. 51.209 Section 51.209... Obligations of All Local Exchange Carriers § 51.209 Toll dialing parity. (a) A LEC shall implement throughout each state in which it offers telephone exchange service intraLATA and interLATA toll dialing...

  1. 47 CFR 51.205 - Dialing parity: General.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 3 2013-10-01 2013-10-01 false Dialing parity: General. 51.205 Section 51.205... Obligations of All Local Exchange Carriers § 51.205 Dialing parity: General. A local exchange carrier (LEC) shall provide local and toll dialing parity to competing providers of telephone exchange service...

  2. 47 CFR 51.205 - Dialing parity: General.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 3 2011-10-01 2011-10-01 false Dialing parity: General. 51.205 Section 51.205... Obligations of All Local Exchange Carriers § 51.205 Dialing parity: General. A local exchange carrier (LEC) shall provide local and toll dialing parity to competing providers of telephone exchange service...

  3. 47 CFR 51.205 - Dialing parity: General.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 3 2014-10-01 2014-10-01 false Dialing parity: General. 51.205 Section 51.205... Obligations of All Local Exchange Carriers § 51.205 Dialing parity: General. A local exchange carrier (LEC) shall provide local and toll dialing parity to competing providers of telephone exchange service...

  4. 47 CFR 51.209 - Toll dialing parity.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 3 2011-10-01 2011-10-01 false Toll dialing parity. 51.209 Section 51.209... Obligations of All Local Exchange Carriers § 51.209 Toll dialing parity. (a) A LEC shall implement throughout each state in which it offers telephone exchange service intraLATA and interLATA toll dialing...

  5. 47 CFR 51.209 - Toll dialing parity.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 3 2014-10-01 2014-10-01 false Toll dialing parity. 51.209 Section 51.209... Obligations of All Local Exchange Carriers § 51.209 Toll dialing parity. (a) A LEC shall implement throughout each state in which it offers telephone exchange service intraLATA and interLATA toll dialing...

  6. 47 CFR 51.205 - Dialing parity: General.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Dialing parity: General. 51.205 Section 51.205... Obligations of All Local Exchange Carriers § 51.205 Dialing parity: General. A local exchange carrier (LEC) shall provide local and toll dialing parity to competing providers of telephone exchange service...

  7. 47 CFR 51.215 - Dialing parity: Cost recovery.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 3 2012-10-01 2012-10-01 false Dialing parity: Cost recovery. 51.215 Section... (CONTINUED) INTERCONNECTION Obligations of All Local Exchange Carriers § 51.215 Dialing parity: Cost recovery. (a) A LEC may recover the incremental costs necessary for the implementation of toll dialing...

  8. 47 CFR 51.213 - Toll dialing parity implementation plans.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 3 2011-10-01 2011-10-01 false Toll dialing parity implementation plans. 51... parity implementation plans. (a) A LEC must file a plan for providing intraLATA toll dialing parity... dialing parity within a state until the implementation plan has been approved by the appropriate...

  9. 47 CFR 51.215 - Dialing parity: Cost recovery.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 3 2014-10-01 2014-10-01 false Dialing parity: Cost recovery. 51.215 Section... (CONTINUED) INTERCONNECTION Obligations of All Local Exchange Carriers § 51.215 Dialing parity: Cost recovery. (a) A LEC may recover the incremental costs necessary for the implementation of toll dialing...

  10. Dial-A-Tape for Continuing Education

    ERIC Educational Resources Information Center

    Niles, Anne McKee

    1972-01-01

    Nursing Dial Access was designed primarily to meet the needs of the nurse practicing in an isolated setting in order to facilitate continuing education or for review of previously acquired knowledge. The service has also been widely used as a teaching resource by instructors and by in-service educators in staff development programs. (Author/AS)

  11. Development of Laser, Detector, and Receiver Systems for an Atmospheric CO2 Lidar Profiling System

    NASA Technical Reports Server (NTRS)

    Ismail, Syed; Koch, Grady; Abedin, Nurul; Refaat, Tamer; Rubio, Manuel; Singh, Upendra

    2008-01-01

    A ground-based Differential Absorption Lidar (DIAL) is being developed with the capability to measure range-resolved and column amounts of atmospheric CO2. This system is also capable of providing high-resolution aerosol profiles and cloud distributions. It is being developed as part of the NASA Earth Science Technology Office s Instrument Incubator Program. This three year program involves the design, development, evaluation, and fielding of a ground-based CO2 profiling system. At the end of a three-year development this instrument is expected to be capable of making measurements in the lower troposphere and boundary layer where the sources and sinks of CO2 are located. It will be a valuable tool in the validation of NASA Orbiting Carbon Observatory (OCO) measurements of column CO2 and suitable for deployment in the North American Carbon Program (NACP) regional intensive field campaigns. The system can also be used as a test-bed for the evaluation of lidar technologies for space-application. This DIAL system leverages 2-micron laser technology developed under a number of NASA programs to develop new solid-state laser technology that provides high pulse energy, tunable, wavelength-stabilized, and double-pulsed lasers that are operable over pre-selected temperature insensitive strong CO2 absorption lines suitable for profiling of lower tropospheric CO2. It also incorporates new high quantum efficiency, high gain, and relatively low noise phototransistors, and a new receiver/signal processor system to achieve high precision DIAL measurements.

  12. CO2 laser design procedure.

    NASA Technical Reports Server (NTRS)

    Fahlen, T. S.

    1973-01-01

    A simple but powerful formalism is presented that allows one to physically design a sealed CO2 laser of any specified fundamental transverse-mode output power. The design material presented, graphically whenever possible, also allows one to determine the effect on the others of varying one design parameter. Although the formalism presented is based on some empirical and some theoretical parametric interrelationships pertinent to the CO2 laser, the treatment is general and with appropriate adjustments can be applied to other laser systems as well. The design of a 5-W sealed CO2 laser is presented to illustrate the use of the formalism developed.

  13. Development of a Ground-Based Differential Absorption Lidar for High Accurate Measurements of Vertical CO2 Concentration Profiles

    NASA Astrophysics Data System (ADS)

    Nagasawa, Chikao; Abo, Makoto; Shibata, Yasukuni; Nagai, Tomohiro; Nakazato, Masahisa; Sakai, Tetsu; Tsukamoto, Makoto; Sakaizawa, Daisuku

    2010-05-01

    High-accurate vertical carbon dioxide (CO2) profiles are highly desirable in the inverse method to improve quantification and understanding of the global sink and source of CO2, and also global climate change. We have developed a ground based 1.6μm differential absorption lidar (DIAL) to achieve high accurate measurements of vertical CO2 profiles in the atmosphere. The DIAL system is constructed from the optical parametric oscillation(OPO) transmitter and the direct detection receiving system that included a near-infrared photomultiplier tube operating at photon counting mode. The primitive DIAL measurement was achieved successfully the vertical CO2 profile up to 7 km altitude with an error less than 1.0 % by integration time of 50 minutes and vertical resolution of 150m. We are developing the next generation 1.6 μm DIAL that can measure simultaneously the vertical CO2 concentration, temperature and pressure profiles in the atmosphere. The output laser of the OPO is 20mJ at a 500 Hz repetition rate and a 600mm diameter telescope is employed for this measurement. A very narrow interference filter (0.5nm FWHM) is used for daytime measurement. As the spectra of absorption lines of any molecules are influenced basically by the temperature and pressure in the atmosphere, it is important to measure them simultaneously so that the better accuracy of the DIAL measurement may be realized. Moreover, the value of the retrieved CO2 concentration will be improved remarkably by processing the iteration assignment of CO2 concentration, temperature and pressure, which measured by DIAL techniques. This work was financially supported by the Japan EOS Promotion Program by the MEXT Japan and System Development Program for Advanced Measurement and Analysis by the JST. Reference D. Sakaizawa, C. Nagasawa, T. Nagai, M. Abo, Y. Shibata, H. Nagai, M. Nakazato, and T. Sakai, Development of a 1.6μm differential absorption lidar with a quasi-phase-matching optical parametric oscillator and

  14. Turbulent CO2 Flux Measurements by Lidar: Length Scales, Results and Comparison with In-Situ Sensors

    NASA Technical Reports Server (NTRS)

    Gilbert, Fabien; Koch, Grady J.; Beyon, Jeffrey Y.; Hilton, Timothy W.; Davis, Kenneth J.; Andrews, Arlyn; Ismail, Syed; Singh, Upendra N.

    2009-01-01

    The vertical CO2 flux in the atmospheric boundary layer (ABL) is investigated with a Doppler differential absorption lidar (DIAL). The instrument was operated next to the WLEF instrumented tall tower in Park Falls, Wisconsin during three days and nights in June 2007. Profiles of turbulent CO2 mixing ratio and vertical velocity fluctuations are measured by in-situ sensors and Doppler DIAL. Time and space scales of turbulence are precisely defined in the ABL. The eddy-covariance method is applied to calculate turbulent CO2 flux both by lidar and in-situ sensors. We show preliminary mean lidar CO2 flux measurements in the ABL with a time and space resolution of 6 h and 1500 m respectively. The flux instrumental errors decrease linearly with the standard deviation of the CO2 data, as expected. Although turbulent fluctuations of CO2 are negligible with respect to the mean (0.1 %), we show that the eddy-covariance method can provide 2-h, 150-m range resolved CO2 flux estimates as long as the CO2 mixing ratio instrumental error is no greater than 10 ppm and the vertical velocity error is lower than the natural fluctuations over a time resolution of 10 s.

  15. Co2 On Titan's Surface

    NASA Astrophysics Data System (ADS)

    McCord, Thomas B.; Combe, J.; Hayne, P.; Hansen, G. B.

    2007-10-01

    Evidence is reported for the presence of CO2 on the surface of Titan from the Cassini VIMS (an imaging visual and IR spectrometer) data (McCord et al., 2006, 2007). CO2 can be expected on Titan from basic planetary evolution models. It was also suggested as a plausible spectral component for bright material near the Huygens landing site (Rodriguez et al., 2006), based on structure in the 1.59-µm region. Hartung et al. (2006) searched for CO2 in one hemisphere, but they were able only to set an upper limit on the possible spatial coverage by pure CO2. Barnes et al., (2006) suggested CO2 as a possible candidate material for a 5-µm-bright region, named Tsegihi, based on the high 5-µm reflectance. However, these results are not inconsistent with our report. The evidence we report is three-fold: 1) A weak absorption near 4.9 µm in the 5-µm methane window for the Tui Regio region; 2) The spectral contrast between the 2.7- and 2.8-µm methane subwindows for the regions exhibiting the 4.9-µm absorption, with stronger absorption correlating with stronger contrast; and 3) the overall shape of the CO2 spectrum (for several grain-sizes) is consistent with the spectrum of one of the fundamental surface spectral components, as deduced by spectral mixture analysis modeling. The Tui Regio feature exhibits the strongest evidence in all three categories. Studies of this feature's morphology and albedo markings have suggested to some that it may be an active cryovolcanic feature (Barnes et al., 2006). If so, CO2 could be erupting and depositing as a frost. This likely happened elsewhere and at other times. Thus, CO2 could be a major constituent of the surface, but over time it may be mixed with other constituents, such as spectrally neutral organics raining from the atmosphere, thereby reducing the strength of its spectral signature.

  16. New ground-based lidar enables volcanic CO2 flux measurements

    PubMed Central

    Aiuppa, Alessandro; Fiorani, Luca; Santoro, Simone; Parracino, Stefano; Nuvoli, Marcello; Chiodini, Giovanni; Minopoli, Carmine; Tamburello, Giancarlo

    2015-01-01

    There have been substantial advances in the ability to monitor the activity of hazardous volcanoes in recent decades. However, obtaining early warning of eruptions remains challenging, because the patterns and consequences of volcanic unrests are both complex and nonlinear. Measuring volcanic gases has long been a key aspect of volcano monitoring since these mobile fluids should reach the surface long before the magma. There has been considerable progress in methods for remote and in-situ gas sensing, but measuring the flux of volcanic CO2—the most reliable gas precursor to an eruption—has remained a challenge. Here we report on the first direct quantitative measurements of the volcanic CO2 flux using a newly designed differential absorption lidar (DIAL), which were performed at the restless Campi Flegrei volcano. We show that DIAL makes it possible to remotely obtain volcanic CO2 flux time series with a high temporal resolution (tens of minutes) and accuracy (<30%). The ability of this lidar to remotely sense volcanic CO2 represents a major step forward in volcano monitoring, and will contribute improved volcanic CO2 flux inventories. Our results also demonstrate the unusually strong degassing behavior of Campi Flegrei fumaroles in the current ongoing state of unrest. PMID:26324399

  17. New ground-based lidar enables volcanic CO2 flux measurements.

    PubMed

    Aiuppa, Alessandro; Fiorani, Luca; Santoro, Simone; Parracino, Stefano; Nuvoli, Marcello; Chiodini, Giovanni; Minopoli, Carmine; Tamburello, Giancarlo

    2015-09-01

    There have been substantial advances in the ability to monitor the activity of hazardous volcanoes in recent decades. However, obtaining early warning of eruptions remains challenging, because the patterns and consequences of volcanic unrests are both complex and nonlinear. Measuring volcanic gases has long been a key aspect of volcano monitoring since these mobile fluids should reach the surface long before the magma. There has been considerable progress in methods for remote and in-situ gas sensing, but measuring the flux of volcanic CO2-the most reliable gas precursor to an eruption-has remained a challenge. Here we report on the first direct quantitative measurements of the volcanic CO2 flux using a newly designed differential absorption lidar (DIAL), which were performed at the restless Campi Flegrei volcano. We show that DIAL makes it possible to remotely obtain volcanic CO2 flux time series with a high temporal resolution (tens of minutes) and accuracy (<30%). The ability of this lidar to remotely sense volcanic CO2 represents a major step forward in volcano monitoring, and will contribute improved volcanic CO2 flux inventories. Our results also demonstrate the unusually strong degassing behavior of Campi Flegrei fumaroles in the current ongoing state of unrest.

  18. Correlation of DIAL Ozone Observations with Lightning

    NASA Technical Reports Server (NTRS)

    Peterson, Harold S.; Kuang, Shi; Koshak, William J.; Newchurch, Mike

    2014-01-01

    The purpose of this project is to see whether ozone maxima measured by the DIfferential Absorption Lidar (DIAL) instrument in Huntsville, AL may be traced back to lightning events occurring 24-48 hours beforehand. The methodology is to start with lidar measurements of ozone from DIAL. The HYbrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model is then used to determine the origin of these ozone maxima 24-48 hours prior. Data from the National Lightning Detection Network (NLDN) are used to examine the presence/absence of lightning along the trajectory. This type of analysis suggests that lightning-produced NOx may be responsible for some of the ozone maxima over Huntsville.

  19. Airborne water vapor DIAL system development

    NASA Technical Reports Server (NTRS)

    Higdon, Noah S.; Browell, Edward V.; Ponsardin, Patrick; Grossmann, Benoist E.

    1990-01-01

    A differential absorption lidar (DIAL) system developed at NASA Langley Research Center for the remote measurement of atmospheric H2O and aerosols from an aircraft is briefly discussed. This DIAL system utilizes a Nd:YAG laser-pumped dye laser as the off-line transmitter and a narrowband, tunable Alexandrite laser as the on-line transmitter. A 1-m monochromator and a multipass absorption cell are used to position the on-line laser to the center of the H2O line. The receiver system has a 14-in. diameter, f/7 Celestron telescope to collect the backscattered laser light and focus in into the detector optics. Return signals are converted to electrical signals by the optical detector and are digitalized and stored on magnetic tape. The results of fligh tests of the system are shown.

  20. Correlation of DIAL Ozone Observations with Lightning

    NASA Technical Reports Server (NTRS)

    Peterson, Harold S.; Kuang, Shi; Koshak, William J.; Newchurch, Mike

    2013-01-01

    The purpose of this project is to see whether ozone maxima measured by the DIfferential Absorption Lidar (DIAL) instrument in Huntsville, AL may be traced back to lightning events occurring 24- 48 hours beforehand. The methodology is to start with lidar measurements of ozone from DIAL as well as ozonesonde measurements. The HYbrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model is then used to determine the origin of these ozone maxima 24-48 hours prior. Data from the National Lightning Detection Network (NLDN) are used to examine the presence/absence of lightning along the trajectory. This type of analysis suggests that lightning-produced NOx may be responsible for some of the ozone maxima over Huntsville.

  1. CO2 Sequestration Crosswell Monitoring

    NASA Astrophysics Data System (ADS)

    Morency, C.; Luo, Y.; Tromp, J.

    2010-12-01

    Geologic sequestration of CO2, a green house gas, represents an effort to reduce the large amount of CO2 generated as a by-product of fossil fuels combustion and emitted into the atmosphere. This process of sequestration involves CO2 storage deep underground into highly permeable porous media sealed by caprock. "4D seismics" is a natural non-intrusive monitoring technique which involves 3D time-lapse seismic surveys. The success of monitoring CO2 movement relies upon a proper description of the physics of the problem. We realize time-lapse migrations comparing acoustic, elastic (with or without Gassmann's formulae), and poroelastic simulations of 4D seismic imaging. This approach highlights the influence of using different physical theories on interpreting seismic data, and, more importantly, on extracting the CO2 signature from the seismic wave field. We investigate various types of inversions using (1) P-wave traveltimes, (2) P- & S-wave traveltimes and (3) P- & S-wave traveltimes and amplitudes. Simulations are performed using a spectral-element method, and finite-frequency sensitivity kernels, used in the non-linear iterative inversions, are calculated based on an adjoint method. Biot's equations are implemented in the forward and adjoint simulations to account for poroelastic effects.

  2. ACCURACY OF CO2 SENSORS

    SciTech Connect

    Fisk, William J.; Faulkner, David; Sullivan, Douglas P.

    2008-10-01

    Are the carbon dioxide (CO2) sensors in your demand controlled ventilation systems sufficiently accurate? The data from these sensors are used to automatically modulate minimum rates of outdoor air ventilation. The goal is to keep ventilation rates at or above design requirements while adjusting the ventilation rate with changes in occupancy in order to save energy. Studies of energy savings from demand controlled ventilation and of the relationship of indoor CO2 concentrations with health and work performance provide a strong rationale for use of indoor CO2 data to control minimum ventilation rates1-7. However, this strategy will only be effective if, in practice, the CO2 sensors have a reasonable accuracy. The objective of this study was; therefore, to determine if CO2 sensor performance, in practice, is generally acceptable or problematic. This article provides a summary of study methods and findings ? additional details are available in a paper in the proceedings of the ASHRAE IAQ?2007 Conference8.

  3. D0 Cryogenic Auto Dialing Alarm System

    SciTech Connect

    Markely, D.; /Fermilab

    1992-08-03

    The Automatic Dialing system purchased by D0 is intended to help make the D0 cryogenic system operate unattended by cryogenic operating personnel. The auto dialer is completely programmable and is voice synthesized. The auto dialer was purchased with 32 bistable inputs, but is expandable to 64 bistable inputs with the purchase of more electronic cards at an approximate cost of $260 per card (8 bistable inputs). The auto dialer also has the capability for analog inputs, analog outputs, and bistable outputs none of which D0 uses or intends to use. The auto dialer can be called on its operating phone line to describe current alarms with the proper password. The Auto Dialer can dial lab extensions, lab pagers, and any number outside the lab. It cannot dial a long distance pager. The auto dialer monitors alarms and alarm conditions via the T1565 PLC, upon an alarm condition it initiates a phone calling sequence of preprogrammed lists with assigned priorities. When someone is reached, the auto dialer describes the individual alarm it is calling for, by a preprogrammed set of words for that individual alarm, spoken by a female voice. The called person then has a chance to acknowledge the alarm over the telephone, if the alarm is not acknowledged the auto dialer will disconnect and call the next person on the list. The auto dialer will continue to cycle through the list until it is acknowledged, reset, or the alarm condition no longer exists.

  4. Update on CO2 emissions

    SciTech Connect

    Friedingstein, P.; Houghton, R.A.; Marland, Gregg; Hackler, J.; Boden, Thomas A; Conway, T.J.; Canadell, J.G.; Raupach, Mike; Ciais, Philippe; Le Quere, Corrine

    2010-12-01

    Emissions of CO2 are the main contributor to anthropogenic climate change. Here we present updated information on their present and near-future estimates. We calculate that global CO2 emissions from fossil fuel burning decreased by 1.3% in 2009 owing to the global financial and economic crisis that started in 2008; this is half the decrease anticipated a year ago1. If economic growth proceeds as expected2, emissions are projected to increase by more than 3% in 2010, approaching the high emissions growth rates that were observed from 2000 to 20081, 3, 4. We estimate that recent CO2 emissions from deforestation and other land-use changes (LUCs) have declined compared with the 1990s, primarily because of reduced rates of deforestation in the tropics5 and a smaller contribution owing to forest regrowth elsewhere.

  5. Differential Absorption Lidar (DIAL) Measurements from Air and Space

    NASA Technical Reports Server (NTRS)

    Browell, E. V.; Ismail, S.; Grant, W. B.

    1998-01-01

    Differential absorption lidar (DIAL) systems have been used for the measurement of ozone, water vapor, and aerosols from aircraft platforms for over 18 years, yielding new insights into atmospheric chemistry, composition, and dynamics in large-scale field experiments conducted all over the world. The successful deployment of the lidar in-space technology experiment (LITE) in September 1994 demonstrated that space-based lidars can also collect valuable information on the global atmosphere. This paper reviews some of the contributions of the NASA Langley Research Center's airborne ozone and water vapor DIAL systems and space-based LITE system to the understanding of the atmosphere and discusses the feasibility and advantages of putting DIAL systems in space for routine atmospheric measurements of ozone and/or water vapor and aerosols and clouds. The technology and applications of the differential absorption lidar (DIAL) technique have progressed significantly since the first DIAL measurements of Schotland, and airborne DIAL measurements of ozone and water vapor are frequently being made in a wide range of field experiments. In addition, plans are underway to develop DIAL systems for use on satellites for continuous global measurements. This paper will highlight the history of airborne lidar and DIAL systems, summarize the major accomplishments of the NASA Langley DIAL program, and discuss specifications and goals for DIAL systems in space.

  6. The CO2nnect activities

    NASA Astrophysics Data System (ADS)

    Eugenia, Marcu

    2014-05-01

    Climate change is one of the biggest challenges we face today. A first step is the understanding the problem, more exactly what is the challenge and the differences people can make. Pupils need a wide competencies to meet the challenges of sustainable development - including climate change. The CO2nnect activities are designed to support learning which can provide pupils the abilities, skills, attitudes and awareness as well as knowledge and understanding of the issues. The project "Together for a clean and healthy world" is part of "The Global Educational Campaign CO2nnect- CO2 on the way to school" and it was held in our school in the period between February and October 2009. It contained a variety of curricular and extra-curricular activities, adapted to students aged from 11 to 15. These activities aimed to develop in students the necessary skills to understanding man's active role in improving the quality of the environment, putting an end to its degrading process and to reducing the effects of climate changes caused by the human intervention in nature, including transport- a source of CO2 pollution. The activity which I propose can be easily adapted to a wide range of age groups and linked to the curricula of many subjects: - Investigate CO2 emissions from travel to school -Share the findings using an international database -Compare and discuss CO2 emissions -Submit questions to a climate- and transport expert -Partner with other schools -Meet with people in your community to discuss emissions from transport Intended learning outcomes for pupils who participate in the CO2nnect campaign are: Understanding of the interconnected mobility- and climate change issue climate change, its causes and consequences greenhouse-gas emissions from transport and mobility the interlinking of social, environmental, cultural and economic aspects of the local transport system how individual choices and participation can contribute to creating a more sustainable development

  7. The NASA Langley High Altitude Lidar Observatory (HALO) - Advancements in Airborne DIAL Measurements of CH4 and H2O

    NASA Astrophysics Data System (ADS)

    Nehrir, A. R.; Hair, J. W.; Ferrare, R. A.; Hostetler, C. A.; Notari, A.; Collins, J. E., Jr.; Hare, R. J.; Harper, D. B.; Antill, C.; Cook, A. L.; Young, J.; Chuang, T.; Welch, W.

    2016-12-01

    Atmospheric methane (CH4) has the second largest radiative forcing of the long-lived greenhouse gasses (GHG) after carbon dioxide. However, methane's much shorter atmospheric lifetime and much stronger warming potential make its radiative forcing equivalent to that for CO2 over a 20-year time horizon which makes CH4 a particularly attractive target for mitigation strategies. Similar to CH4, water vapor (H2O) is the most dominant of the short-lived GHG in the atmosphere and plays a key role in many atmospheric processes. Atmospheric H2O concentrations span over four orders of magnitude from the planetary boundary layer where high impact weather initiates to lower levels in the upper troposphere and lower stratosphere where water vapor has significant and long term impacts on the Earth's radiation budget. Active remote sensing employing the differential absorption lidar (DIAL) technique enables scientific assessments of both natural and anthropogenic sources and sinks of CH4 with high accuracy and precision as well as and its impacts on the climate. The DIAL technique also allows for profiling of tropospheric water vapor for weather and climate applications with unprecedented spatial and temporal resolution. NASA Langley is developing the High Altitude Lidar Observatory (HALO) lidar system to address the observational needs of NASA's weather, climate, carbon cycle, and atmospheric composition focus areas. HALO is a multi-function airborne lidar being developed to measure atmospheric H2O and CH4 mixing ratios and aerosol and cloud optical properties using the DIAL and High Spectral Resolution Lidar (HSRL) techniques, respectively. HALO is designed as an airborne simulator for future space based DIAL missions and will serve as test bed for risk reduction of key technologies required of future space based GHG DIAL missions. A system level overview and up-to-date progress of the HALO lidar will be presented. Simulations on the expected accuracy and precision of HALO CH4

  8. Reducing cement's CO2 footprint

    USGS Publications Warehouse

    van Oss, Hendrik G.

    2011-01-01

    The manufacturing process for Portland cement causes high levels of greenhouse gas emissions. However, environmental impacts can be reduced by using more energy-efficient kilns and replacing fossil energy with alternative fuels. Although carbon capture and new cements with less CO2 emission are still in the experimental phase, all these innovations can help develop a cleaner cement industry.

  9. Airborne 2-Micron Double-Pulsed Integrated Path Differential Absorption Lidar for Column CO2 Measurement

    NASA Technical Reports Server (NTRS)

    Singh, Upendra N.; Yu, Jirong; Petros, Mulugeta; Refaat, Tamer F.; Remus, Ruben G.; Fay, James J.; Reithmaier, Karl

    2014-01-01

    Double-pulse 2-micron lasers have been demonstrated with energy as high as 600 millijouls and up to 10 Hz repetition rate. The two laser pulses are separated by 200 microseconds and can be tuned and locked separately. Applying double-pulse laser in DIAL system enhances the CO2 measurement capability by increasing the overlap of the sampled volume between the on-line and off-line. To avoid detection complicity, integrated path differential absorption (IPDA) lidar provides higher signal-to-noise ratio measurement compared to conventional range-resolved DIAL. Rather than weak atmospheric scattering returns, IPDA rely on the much stronger hard target returns that is best suited for airborne platforms. In addition, the IPDA technique measures the total integrated column content from the instrument to the hard target but with weighting that can be tuned by the transmitter. Therefore, the transmitter could be tuned to weight the column measurement to the surface for optimum CO2 interaction studies or up to the free troposphere for optimum transport studies. Currently, NASA LaRC is developing and integrating a double-Pulsed 2-micron direct detection IPDA lidar for CO2 column measurement from an airborne platform. The presentation will describe the development of the 2-micron IPDA lidar system and present the airborne measurement of column CO2 and will compare to in-situ measurement for various ground target of different reflectivity.

  10. Airborne 2-micron double-pulsed integrated path differential absorption lidar for column CO2 measurement

    NASA Astrophysics Data System (ADS)

    Singh, Upendra N.; Yu, Jirong; Petros, Mulugeta; Refaat, Tamer F.; Remus, Ruben G.; Fay, James J.; Reithmaier, Karl

    2014-10-01

    Double-pulse 2-micron lasers have been demonstrated with energy as high as 600 mJ and up to 10 Hz repetition rate. The two laser pulses are separated by 200 µs and can be tuned and locked separately. Applying double-pulse laser in DIAL system enhances the CO2 measurement capability by increasing the overlap of the sampled volume between the on-line and off-line. To avoid detection complicity, integrated path differential absorption (IPDA) lidar provides higher signal-to-noise ratio measurement compared to conventional range-resolved DIAL. Rather than weak atmospheric scattering returns, IPDA rely on the much stronger hard target returns that is best suited for airborne platforms. In addition, the IPDA technique measures the total integrated column content from the instrument to the hard target but with weighting that can be tuned by the transmitter. Therefore, the transmitter could be tuned to weight the column measurement to the surface for optimum CO2 interaction studies or up to the free troposphere for optimum transport studies. Currently, NASA LaRC is developing and integrating a double-Pulsed 2-µm direct detection IPDA lidar for CO2 column measurement from an airborne platform. The presentation will describe the development of the 2-μm IPDA lidar system and present the airborne measurement of column CO2 and will compare to in-situ measurement for various ground target of different reflectivity.

  11. Automatic calibration of dial gauges based on computer vision

    NASA Astrophysics Data System (ADS)

    Zhao, Jun; Feng, Haiping; Kong, Ming

    2008-10-01

    Against the image characteristics of dial gauges, an automatic detection system of dial gauges is designed and implemented by using the technology of computer vision technology and digital image processing methods. Improved image subtraction method and adaptive threshold segmentation method is used for previous processing; a new method named as region-segmentation is proposed to partition the dial image, only the useful blocks of the dial image is processed no the other area, this method reduces the computation amount greatly, and improves the processing speed effectively. This method has been applied in the automatic detection system of dial gauges, which makes it possible for the detection of dial gauges to be finished intelligent, automatically and rapidly.

  12. Vision system for dial gage torque wrench calibration

    NASA Astrophysics Data System (ADS)

    Aggarwal, Neelam; Doiron, Theodore D.; Sanghera, Paramjeet S.

    1993-11-01

    In this paper, we present the development of a fast and robust vision system which, in conjunction with the Dial Gage Calibration system developed by AKO Inc., will be used by the U.S. Army in calibrating dial gage torque wrenches. The vision system detects the change in the angular position of the dial pointer in a dial gage. The angular change is proportional to the applied torque. The input to the system is a sequence of images of the torque wrench dial gage taken at different dial pointer positions. The system then reports the angular difference between the different positions. The primary components of this vision system include modules for image acquisition, linear feature extraction and angle measurements. For each of these modules, several techniques were evaluated and the most applicable one was selected. This system has numerous other applications like vision systems to read and calibrate analog instruments.

  13. Design and development of a compact lidar/DIAL system for aerial surveillance of urban areas

    NASA Astrophysics Data System (ADS)

    Gaudio, P.; Gelfusa, M.; Malizia, A.; Richetta, M.; Antonucci, A.; Ventura, P.; Murari, A.; Vega, J.

    2013-10-01

    Recently surveying large areas in an automatic way, for early detection of harmful chemical agents, has become a strategic objective of defence and public health organisations. The Lidar-Dial techniques are widely recognized as a cost-effective alternative to monitor large portions of the atmosphere but, up to now, they have been mainly deployed as ground based stations. The design reported in this paper concerns the development of a Lidar-Dial system compact enough to be carried by a small airplane and capable of detecting sudden releases in air of harmful and/or polluting substances. The proposed approach consists of continuous monitoring of the area under surveillance with a Lidar type measurement. Once a significant increase in the density of backscattering substances is revealed, it is intended to switch to the Dial technique to identify the released chemicals and to determine its concentration. In this paper, the design of the proposed system is described and the simulations carried out to determine its performances are reported. For the Lidar measurements, commercially available Nd- YAG laser sources have already been tested and their performances, in combination with avalanche photodiodes, have been experimentally verified to meet the required specifications. With regard to the DIAL measurements, new compact CO2 laser sources are being investigated. The most promising candidate presents an energy per pulse of about 50 mJ typical, sufficient for a range of at least 500m. The laser also provides the so called "agile tuning" option that allows to quickly tune the wavelength. To guarantee continuous, automatic surveying of large areas, innovative solutions are required for the data acquisition, self monitoring of the system and data analysis. The results of the design, the simulations and some preliminary tests illustrate the potential of the chosen, integrated approach.

  14. Development of a laser remote sensing instrument to measure sub-aerial volcanic CO2 fluxes

    NASA Astrophysics Data System (ADS)

    Queisser, Manuel; Burton, Mike

    2016-04-01

    A thorough quantification of volcanic CO2 fluxes would lead to an enhanced understanding of the role of volcanoes in the geological carbon cycle. This would enable a more subtle understanding of human impact on that cycle. Furthermore, variations in volcanic CO2 emissions are a key to understanding volcanic processes such as eruption phenomenology. However, measuring fluxes of volcanic CO2 is challenging as volcanic CO2 concentrations are modest compared with the ambient CO2 concentration (~400 ppm) . Volcanic CO2 quickly dilutes with the background air. For Mt. Etna (Italy), for instance, 1000 m downwind from the crater, dispersion modelling yields a signal of ~4 ppm only. It is for this reason that many magmatic CO2 concentration measurements focus on in situ techniques, such as direct sampling Giggenbach bottles, chemical sensors, IR absorption spectrometers or mass spectrometers. However, emission rates are highly variable in time and space. Point measurements fail to account for this variability. Inferring 1-D or 2-D gas concentration profiles, necessary to estimate gas fluxes, from point measurements may thus lead to erroneous flux estimations. Moreover, in situ probing is time consuming and, since many volcanoes emit toxic gases and are dangerous as mountains, may raise safety concerns. In addition, degassing is often diffuse and spatially extended, which makes a measurement approach with spatial coverage desirable. There are techniques that allow to indirectly retrieve CO2 fluxes from correlated SO2 concentrations and fluxes. However, they still rely on point measurements of CO2 and are prone to errors of SO2 fluxes due to light dilution and depend on blue sky conditions. Here, we present a new remote sensing instrument, developed with the ERC project CO2Volc, which measures 1-D column amounts of CO2 in the atmosphere with sufficient sensitivity to reveal the contribution of magmatic CO2. Based on differential absorption LIDAR (DIAL) the instrument measures

  15. Improving CO2 permeation and separation performance of CO2-philic polymer membrane by blending CO2 absorbents

    NASA Astrophysics Data System (ADS)

    Cheng, Jun; Hu, Leiqing; Li, Yannan; Liu, Jianzhong; Zhou, Junhu; Cen, Kefa

    2017-07-01

    To research effects of CO2 absorption capacity and type of CO2 absorbent on the CO2 separation and free-volume properties of facilitated transport membranes, two types of CO2 absorbents, namely monoethanolamine (MEA) and ionic liquids (ILs:[P66614][Triz] and [P66614][2-Op]), were adopted. The CO2 absorption capacities of MEA, [P66614][Triz] and [P66614][2-Op] were about 0.561 mol CO2 per mol, 0.95 mol CO2 per mol and 1.60 mol CO2 per mol, respectively. All mean free-volume hole radiuses of membranes decreased after blending CO2 absorbents. After polymer membrane blended with two ILs, number of free-volume hole increased, resulting in modest increase of the fractional free volume. Both CO2 permeability and selectivity increased after blending MEA and ILs. The increasing range of CO2 permeability corresponded with CO2 absorption capacity of CO2 absorbents, and membrane blending with [P66614][2-Op] showed the highest CO2 permeability of 672.1 Barrers at 25 °C. Pebax/PEGDME membrane blending with MEA obtained the highest CO2/H2 and CO2/CH4 selectivity at 17.8 and 20.5, respectively.

  16. CO2 Acquisition Membrane (CAM)

    NASA Technical Reports Server (NTRS)

    Mason, Larry W.; Way, J. Douglas; Vlasse, Marcus

    2003-01-01

    The objective of CAM is to develop, test, and analyze thin film membrane materials for separation and purification of carbon dioxide (CO2) from mixtures of gases, such as those found in the Martian atmosphere. The membranes are targeted toward In Situ Resource Utilization (ISRU) applications that will operate in extraterrestrial environments and support future unmanned and human space missions. A primary application is the Sabatier Electrolysis process that uses Mars atmosphere CO2 as raw material for producing water, oxygen, and methane for rocket fuel and habitat support. Other applications include use as an inlet filter to collect and concentrate Mars atmospheric argon and nitrogen gases for habitat pressurization, and to remove CO2 from breathing gases in Closed Environment Life Support Systems (CELSS). CAM membrane materials include crystalline faujasite (FAU) zeolite and rubbery polymers such as silicone rubber (PDMS) that have been shown in the literature and via molecular simulation to favor adsorption and permeation of CO2 over nitrogen and argon. Pure gas permeation tests using commercial PDMS membranes have shown that both CO2 permeance and the separation factor relative to other gases increase as the temperature decreases, and low (Delta)P(Sub CO2) favors higher separation factors. The ideal CO2/N2 separation factor increases from 7.5 to 17.5 as temperature decreases from 22 C to -30 C. For gas mixtures containing CO2, N2, and Ar, plasticization decreased the separation factors from 4.5 to 6 over the same temperature range. We currently synthesize and test our own Na(+) FAU zeolite membranes using standard formulations and secondary growth methods on porous alumina. Preliminary tests with a Na(+) FAU membrane at 22 C show a He/SF6 ideal separation factor of 62, exceeding the Knudsen diffusion selectivity by an order of magnitude. This shows that the membrane is relatively free from large defects and associated non-selective (viscous flow) transport

  17. CO2 Acquisition Membrane (CAM)

    NASA Technical Reports Server (NTRS)

    Mason, Larry W.; Way, J. Douglas; Vlasse, Marcus

    2003-01-01

    The objective of CAM is to develop, test, and analyze thin film membrane materials for separation and purification of carbon dioxide (CO2) from mixtures of gases, such as those found in the Martian atmosphere. The membranes are targeted toward In Situ Resource Utilization (ISRU) applications that will operate in extraterrestrial environments and support future unmanned and human space missions. A primary application is the Sabatier Electrolysis process that uses Mars atmosphere CO2 as raw material for producing water, oxygen, and methane for rocket fuel and habitat support. Other applications include use as an inlet filter to collect and concentrate Mars atmospheric argon and nitrogen gases for habitat pressurization, and to remove CO2 from breathing gases in Closed Environment Life Support Systems (CELSS). CAM membrane materials include crystalline faujasite (FAU) zeolite and rubbery polymers such as silicone rubber (PDMS) that have been shown in the literature and via molecular simulation to favor adsorption and permeation of CO2 over nitrogen and argon. Pure gas permeation tests using commercial PDMS membranes have shown that both CO2 permeance and the separation factor relative to other gases increase as the temperature decreases, and low (Delta)P(Sub CO2) favors higher separation factors. The ideal CO2/N2 separation factor increases from 7.5 to 17.5 as temperature decreases from 22 C to -30 C. For gas mixtures containing CO2, N2, and Ar, plasticization decreased the separation factors from 4.5 to 6 over the same temperature range. We currently synthesize and test our own Na(+) FAU zeolite membranes using standard formulations and secondary growth methods on porous alumina. Preliminary tests with a Na(+) FAU membrane at 22 C show a He/SF6 ideal separation factor of 62, exceeding the Knudsen diffusion selectivity by an order of magnitude. This shows that the membrane is relatively free from large defects and associated non-selective (viscous flow) transport

  18. Automated alexandrite transmitter for airborne DIAL experiments

    NASA Technical Reports Server (NTRS)

    Degnan, John J.

    1988-01-01

    An account is given of the performance characteristics and development status of an automated dual alexandrite laser transmitter that is to be carried aloft by NASA's ER-2 research aircraft for water vapor DIAL experiments; these efforts are part of NASA's Lidar Atmospheric Sensing Experiment (LASE). The LASE transmitter encompasses control unit, thermal unit, and two lamp driver unit subsystems. Major reductions in system size and weight relative to commercially available alexandrite lasers were necessary; a total weight of only 330 lbs has been achieved. Attention is given to subsystem flight test results.

  19. Outsourcing CO2 within China.

    PubMed

    Feng, Kuishuang; Davis, Steven J; Sun, Laixiang; Li, Xin; Guan, Dabo; Liu, Weidong; Liu, Zhu; Hubacek, Klaus

    2013-07-09

    Recent studies have shown that the high standard of living enjoyed by people in the richest countries often comes at the expense of CO2 emissions produced with technologies of low efficiency in less affluent, developing countries. Less apparent is that this relationship between developed and developing can exist within a single country's borders, with rich regions consuming and exporting high-value goods and services that depend upon production of low-cost and emission-intensive goods and services from poorer regions in the same country. As the world's largest emitter of CO2, China is a prominent and important example, struggling to balance rapid economic growth and environmental sustainability across provinces that are in very different stages of development. In this study, we track CO2 emissions embodied in products traded among Chinese provinces and internationally. We find that 57% of China's emissions are related to goods that are consumed outside of the province where they are produced. For instance, up to 80% of the emissions related to goods consumed in the highly developed coastal provinces are imported from less developed provinces in central and western China where many low-value-added but high-carbon-intensive goods are produced. Without policy attention to this sort of interprovincial carbon leakage, the less developed provinces will struggle to meet their emissions intensity targets, whereas the more developed provinces might achieve their own targets by further outsourcing. Consumption-based accounting of emissions can thus inform effective and equitable climate policy within China.

  20. Method for wavelength stabilization of pulsed difference frequency laser at 1572 nm for CO(2) detection lidar.

    PubMed

    Gong, Wei; Ma, Xin; Han, Ge; Xiang, Chengzhi; Liang, Ailin; Fu, Weidong

    2015-03-09

    High-accuracy on-line wavelength stabilization is required for differential absorption lidar (DIAL), which is ideal for precisely measuring atmospheric CO(2) concentration. Using a difference-frequency laser, we developed a ground-based 1.57-μm pulsed DIAL for performing atmospheric CO(2) measurements. Owing to the system complexity, lacking phase, and intensity instability, the stabilization method was divided into two parts-wavelength calibration and locking-based on saturated absorption. After obtaining the on-line laser position, accuracy verification using statistical theory and locking stabilization using a one-dimensional template matching method, namely least-squares matching (LSM), were adopted to achieve wavelength locking. The resulting system is capable of generating a stable wavelength.

  1. Integrated UV fluorescence/DIAL model

    SciTech Connect

    Jefferson, K.J.

    1994-06-01

    Current SNL CALIOPE modeling efforts have produced an initial model that addresses DIAL issues of wavelength, hardware design parameters, range evaluation, etc. Although this model is producing valuable results and will be used to support the planning and evaluations necessary for the first ground field experiment, it is expected to have limitations with the complex science issues that affect the CALIOPE program. In particular, the multi-dimensional effects of atmospheric turbulence, plume dynamics, speckle, etc., may be significant issues and must be evaluated in detail as the program moves to the detection of liquids and solids, longer ranges, and elevated platform environments. The goal of the integrated UV fluorescence/DIAL modeling effort is to build upon the knowledge obtained in developing and exercising the initial model to adequately support the future activities of this program. This paper will address the development of the integrated UV model, issues and limiting assumptions that may be needed in order to address the-complex phenomena involved, limits of expected performance, and the potential use of this model.

  2. Estimation of continuous anthropogenic CO2 using CO2, CO, δ13C(CO2) and Δ14C(CO2)

    NASA Astrophysics Data System (ADS)

    Vardag, S. N.; Gerbig, C.; Janssens-Maenhout, G.; Levin, I.

    2015-07-01

    We investigate different methods for estimating anthropogenic CO2 using modelled continuous atmospheric concentrations of CO2 alone, as well as CO2 in combination with the surrogate tracers CO, δ13C(CO2) and Δ14C(CO2). These methods are applied at three hypothetical stations representing rural, urban and polluted conditions. We find that independent of the tracer used, an observation-based estimate of continuous anthropogenic CO2 is not feasible at rural measurement sites due to the low signal to noise ratio of anthropogenic CO2 estimates at such settings. At urban and polluted sites, potential future continuous Δ14C(CO2) measurements with a precision of 5 ‰ or better are most promising for anthropogenic CO2 determination (precision ca. 10-20%), but the insensitivity against CO2 contributions from biofuel emissions may reduce its accuracy in the future. Other tracers, such as δ13C(CO2) and CO could provide an accurate and already available alternative if all CO2 sources in the catchment area are well characterized with respect to their isotopic signature and CO to anthropogenic CO2 ratio. We suggest a strategy for calibrating these source characteristics on an annual basis using precise Δ14C(CO2) measurements on grab samples. The precision of anthropogenic CO2 determination using δ13C(CO2) is largely determined by the measurement precision of δ13C(CO2) and CO2. The precision when using the CO-method is mainly limited by the variation of natural CO sources and CO sinks. At present, continuous anthropogenic CO2 could be determined using the tracers δ13C(CO2) and/or CO with a precision of about 30 %, a mean bias of about 10 % and without significant diurnal discrepancies. This allows significant improvement, validation and bias reduction of highly resolved emission inventories using atmospheric observation and regional modelling.

  3. 47 CFR 51.215 - Dialing parity: Cost recovery.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 3 2011-10-01 2011-10-01 false Dialing parity: Cost recovery. 51.215 Section... (CONTINUED) INTERCONNECTION Obligations of All Local Exchange Carriers § 51.215 Dialing parity: Cost recovery... service in the area served by the LEC, including that LEC. The LEC shall use a cost recovery...

  4. 47 CFR 51.207 - Local dialing parity.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Local dialing parity. 51.207 Section 51.207 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) INTERCONNECTION Obligations of All Local Exchange Carriers § 51.207 Local dialing parity. A LEC shall permit...

  5. 47 CFR 51.207 - Local dialing parity.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 3 2014-10-01 2014-10-01 false Local dialing parity. 51.207 Section 51.207 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) INTERCONNECTION Obligations of All Local Exchange Carriers § 51.207 Local dialing parity. A LEC shall permit...

  6. 47 CFR 51.207 - Local dialing parity.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 3 2011-10-01 2011-10-01 false Local dialing parity. 51.207 Section 51.207 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) INTERCONNECTION Obligations of All Local Exchange Carriers § 51.207 Local dialing parity. A LEC shall permit...

  7. 47 CFR 51.207 - Local dialing parity.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 3 2012-10-01 2012-10-01 false Local dialing parity. 51.207 Section 51.207 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) INTERCONNECTION Obligations of All Local Exchange Carriers § 51.207 Local dialing parity. A LEC shall permit...

  8. Surface Condensation of CO2 onto Kaolinite

    SciTech Connect

    Schaef, Herbert T.; Glezakou, Vassiliki Alexandra; Owen, Antionette T.; Ramprasad, Sudhir; Martin, Paul F.; McGrail, B. Peter

    2014-02-11

    The fundamental adsorption behavior of gaseous and supercritical carbon dioxide (CO2) onto poorly crystalline kaolinite (KGa-2) at conditions relevant to geologic sequestration has been investigated using a quartz crystal microbalance (QCM) and density functional theory (DFT) methods. The QCM data indicated linear adsorption of CO2 (0-0.3 mmol CO2/g KGa-2) onto the kaolinite surface up through the gaseous state (0.186 g/cm3). However in the supercritical region, CO2 adsorption increases dramatically, reaching a peak (0.9-1.0 mmol CO2/g KGa-2) near 0.43 g/cm3, before declining rapidly to surface adsorption values equivalent or below gaseous CO2. This adsorption profile was not observed with He or N2. Comparative density functional studies of CO2 interactions with kaolinite surface models rule out CO2 intercalation and confirm that surface adsorption is favored up to approximately 0.35 g/cm3 of CO2, showing distorted T-shaped CO2-CO2 clustering, typical of supercritical CO2 aggregation over the surface as the density increases. Beyond this point, the adsorption energy gain for any additional CO2 becomes less than the CO2 interaction energy (~0.2 eV) in the supercritical medium resulting in overall desorption of CO2 from the kaolinite surface.

  9. Outsourcing CO2 within China

    PubMed Central

    Feng, Kuishuang; Davis, Steven J.; Sun, Laixiang; Li, Xin; Guan, Dabo; Liu, Weidong; Liu, Zhu; Hubacek, Klaus

    2013-01-01

    Recent studies have shown that the high standard of living enjoyed by people in the richest countries often comes at the expense of CO2 emissions produced with technologies of low efficiency in less affluent, developing countries. Less apparent is that this relationship between developed and developing can exist within a single country’s borders, with rich regions consuming and exporting high-value goods and services that depend upon production of low-cost and emission-intensive goods and services from poorer regions in the same country. As the world’s largest emitter of CO2, China is a prominent and important example, struggling to balance rapid economic growth and environmental sustainability across provinces that are in very different stages of development. In this study, we track CO2 emissions embodied in products traded among Chinese provinces and internationally. We find that 57% of China’s emissions are related to goods that are consumed outside of the province where they are produced. For instance, up to 80% of the emissions related to goods consumed in the highly developed coastal provinces are imported from less developed provinces in central and western China where many low–value-added but high–carbon-intensive goods are produced. Without policy attention to this sort of interprovincial carbon leakage, the less developed provinces will struggle to meet their emissions intensity targets, whereas the more developed provinces might achieve their own targets by further outsourcing. Consumption-based accounting of emissions can thus inform effective and equitable climate policy within China. PMID:23754377

  10. Integrated CO 2 Storage and Brine Extraction

    DOE PAGES

    Hunter, Kelsey; Bielicki, Jeffrey M.; Middleton, Richard; ...

    2017-08-18

    Carbon dioxide (CO2) capture, utilization, and storage (CCUS) can reduce CO2 emissions from fossil fuel power plants by injecting CO2 into deep saline aquifers for storage. CCUS typically increases reservoir pressure which increases costs, because less CO2 can be injected, and risks such as induced seismicity. Extracting brine with enhanced water recovery (EWR) from the CO2 storage reservoir can manage and reduce pressure in the formation, decrease the risks linked to reservoir overpressure (e.g., induced seismicity), increase CO2 storage capacity, and enable CO2 plume management. We modeled scenarios of CO2 injection with EWR into the Rock Springs Uplift (RSU) formationmore » in southwest Wyoming. The Finite Element Heat and Mass Transfer Code (FEHM) was used to model CO2 injection with brine extraction and the corresponding increase in pressure within the RSU. We analyzed the model for pressure management, CO2 storage, CO2 saturation, and brine extraction due to the quantity and location of brine extraction wells. The model limited CO2 injection to a constant pressure increase of two MPa at the injection well with and without extracting brine at hydrostatic pressure. Finally, we found that brine extraction can be used as a technical and cost-effective pressure management strategy to limit reservoir pressure buildup and increase CO2 storage associated with a single injection well.« less

  11. Passive CO2 concentration in higher plants.

    PubMed

    Sage, Rowan F; Khoshravesh, Roxana

    2016-06-01

    Photorespiratory limitations on C3 photosynthesis are substantial in warm, low CO2 conditions. To compensate, certain plants evolved mechanisms to actively concentrate CO2 around Rubisco using ATP-supported CO2 pumps such as C4 photosynthesis. Plants can also passively accumulate CO2 without additional ATP expenditure by localizing the release of photorespired and respired CO2 around Rubisco that is diffusively isolated from peripheral air spaces. Passive accumulation of photorespired CO2 occurs when glycine decarboxylase is localized to vascular sheath cells in what is termed C2 photosynthesis, and through forming sheaths of chloroplasts around the periphery of mesophyll cells. The peripheral sheaths require photorespired CO2 to re-enter chloroplasts where it can be refixed. Passive accumulation of respiratory CO2 is common in organs such as stems, fruits and flowers, due to abundant heterotrophic tissues and high diffusive resistance along the organ periphery. Chloroplasts within these organs are able to exploit this high CO2 to reduce photorespiration. CO2 concentration can also be enhanced passively by channeling respired CO2 from roots and rhizomes into photosynthetic cells of stems and leaves via lacunae, aerenchyma and the xylem stream. Through passive CO2 concentration, C3 species likely improved their carbon economy and maintained fitness during episodes of low atmospheric CO2. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Lasers utilizing CO2 isotopes

    NASA Astrophysics Data System (ADS)

    Pechenin, Yu V.; Domanov, M. S.

    1980-08-01

    The lasing spectra and energy characteristics were investigated for lasers operating with the isotopes 12C16O2, 13C16O2, 12C18O2, and 12C16O18O. It was found that the output power of a laser utilizing the CO2 isotopes was determined by the content of a particular isotope in the carbon dioxide gas. For equal enrichments, all the isotopes investigated, with the exception of 12C16O18O, gave comparable output powers. The unsaturated gains were identical for the most intense transitions of the symmetric molecules; the gain was a factor of two less for the asymmetric molecule. The gain rose linearly with increasing enrichment. The ultimate specific power output, given by the product of the saturation power density and the gain, was practically independent of the enrichment.

  13. Atmospheric CO2 Reconstructions from Polar Ice: What Do High-Resolution CO2 Records and δ13CO2 Analyses Tell Us about Past Climate and Global Carbon Cycle Processes?

    NASA Astrophysics Data System (ADS)

    Schmitt, J.; Eggleston, S.; Marcott, S. A.; Brook, E.; Chappellaz, J. A.; Köhler, P.; Joos, F.; Fischer, H.

    2014-12-01

    Today, a monitoring network measures atmospheric CO2 at high temporal and spatial resolution. Atmospheric transport models then calculate regional CO2 source and sink fluxes. Prior to this instrumental period, archived air, firn air, and air trapped in polar ice are the only direct atmospheric archives to reconstruct past CO2 changes. Only ice from Antarctica allows reliable CO2 measurements, either from classical ice cores or outcropping ice, while Greenland records are subject to in situ production. They provide high-resolution and high-precision CO2 reconstructions up to 800,000 years back in time. Ice core records have revealed an intimate connection between CO2 variations and major changes in Earth's climate and have fundamentally shaped the community's view of the global carbon cycle. Knowing the concentration of past atmospheric CO2 and the other greenhouse gases is key to provide the radiative forcing for climate simulations. Ice core reconstructions broadly fulfilled this task. On the contrary, we are far from a coherent understanding of the mechanisms driving these changes. Analyzing phase relations between CO2, other ice-core derived species, and proxies from marine sediment cores allow for the identification of factors likely responsible for the observed CO2 changes. Specifically, the strength of the Atlantic overturning circulation and Southern Ocean upwelling are thought to be key players. However, the observed CO2 changes cannot uniquely be related to a specific process. Here, stable carbon isotope analysis on CO2 extracted from ice provides additional constraints as any process leads to isotope fractionation of the reservoir. Analytical progress during the last decade affords us with a growing data set on this long-awaited parameter. This presentation provides a state-of-the-art overview on ice-based CO2 and its carbon isotopic signature focusing both on the long-term orbital changes as well as rapid changes documented during the last deglaciation.

  14. End Tidal CO2 Tension

    PubMed Central

    Pugh, Meredith E.; Newman, Alexander L.; Robbins, Ivan M.; Tolle, James; Austin, Eric D.; Newman, John H.

    2011-01-01

    Background: CO2 excretion is impaired in pulmonary arterial hypertension (PAH) due to underlying vascular obstruction and increased dead space. Our aim was to determine whether resting end tidal CO2 (Etco2) could differentiate patients with PAH from those with pulmonary venous hypertension (PVH) or patients without pulmonary hypertension (PH) and whether successful treatment of PAH resulted in higher Etco2 values. Methods: We performed Etco2 measurements for five breaths at rest and after a 6-min walk test (6MWT) in patients seen at our pulmonary vascular center. Mean Etco2 values were correlated with 6-min walk distance and right-sided heart catheterization data. Results: We enrolled 84 patients with PAH, 17 with PVH without left ventricular systolic dysfunction, and seven with no PH and no severe alterations in pulmonary function testing. Etco2 was significantly lower in patients with PAH than in those with no PH and PVH (P < .0001 PAH vs both groups). Etco2 correlated with the pulmonary artery diastolic pressure-to-pulmonary artery occlusion pressure gradient (r = −0.50, P = .0002) and pulmonary vascular resistance (r = −0.44, P = .002). Etco2 after 6MWT correlated with walk distance (r = 0.34, P = .003). In patients with prostaglandin therapy escalation, Etco2 increased in those who had clinical improvement, whereas in patients who did not improve clinically, Etco2 failed to rise (P = .04). Conclusions: Etco2 is a promising tool to differentiate patients with PAH from those with PVH or no PH, correlates with diagnostic and prognostic hemodynamic indicators, and may increase with successful treatment of PAH. PMID:21622547

  15. Sequestration of CO2 by halotolerant algae

    PubMed Central

    2014-01-01

    The potential of halotolerant algae isolated from natural resources was used to study CO2 fixation and algal lipid production. Biological fixation of CO2 in photobioreactor in presence of salinity is exploited. The CO2 concentration 1060 ppm gave the highest biomass yield (700 mg dry wt/l), the highest total lipid content (10.33%) with 80% of CO2 removal. PMID:24847439

  16. Spectral Analysis for DIAL and Lidar Detection of TATP

    DTIC Science & Technology

    2008-05-15

    absorption features near 3.3 Jlil, 8.4 m, and 10.6 m. As such, DIAL systems may be considered for the remote sensing of a TATP gas cloud surrounding a solid...DIAL systems may be considered for the remote sensing of a TA TP gas cloud surrounding a solid sample ofTATP. Toward this end, a tunable C02 DIAL...and Fig 1(b) shows the FTIR-ATR microscope spectrum of TATP. For the vapor phase measurements, a Scm long cell was used at a temperature of 28 °C

  17. Quadrature phase interferometer used to calibrate dial indicator calibrators

    NASA Astrophysics Data System (ADS)

    Huang, Shau-Chi; Liou, Huay-Chung; Peng, Gwo-Sheng; Lu, Ming-Feng

    2001-10-01

    To calibrate dial indicators, gage blocks or dial indicator calibrators are usually used. For better accuracy and resolution, interferometers are used to calibrate dial indicator calibrators. Systematic errors of laser interferometers can be classified into three categories of intrinsic errors, environment errors and installation errors. Intrinsic errors include laser wavelength error, electronic error and optics nonlinearity. In order to achieve nanometer accuracy, minimizing intrinsic error is crucial. In this paper, we will address the problems of minimizing the optics nonlinearity error and describe the discrete-time signal processing method to minimize the electronic error, nonlinearity error and drift by simply using quadrature phase interferometer for nanometer accuracy and linearity.

  18. Nd:Glass-Raman laser for water vapor dial

    NASA Technical Reports Server (NTRS)

    Kagann, R. H.; Petheram, J. C.; Rosenberg, A.

    1986-01-01

    A tunable solid-state Raman shifted laser which was used in a water vapor Differential Absorption Lidar (DIAL) system at 9400 A is described. The DIAL transmitter is based on a tunable glass laser operating at 1.06 microns, a hydrogen Raman cell to shift the radiation to 1.88 microns, and a frequency doubling crystal. The results of measurements which characterize the output of the laser with respect to optimization of optical configuration and of Raman parameters were reported. The DIAL system was also described and preliminary atmospheric returns shown.

  19. Preliminary results of a lidar-dial integrated system for the automatic detection of atmospheric pollutants

    NASA Astrophysics Data System (ADS)

    Gaudio, P.; Gelfusa, M.; Richetta, M.

    2012-11-01

    In the last decades, atmospheric pollution in urban and industrial areas has become a major concern of both developed and developing countries. In this context, surveying relative large areas in an automatic way is an increasing common objective of public health organisations. The Lidar-Dial techniques are widely recognized as a cost-effective approach to monitor large portions of the atmosphere and, for example, they have been successful applied to the early detection of forest fire. The studies and preliminary results reported in this paper concern the development of an integrated Lidar-Dial system able to detect sudden releases in air of harmful and polluting substances. The propose approach consists of continuous monitoring of the area under surveillance with a Lidar type measurement (by means of a low cost system). Once a significant increase in the density of a pollutant is revealed, the Dial technique is used to identify the released chemicals. In this paper, the specifications of the proposed station are discussed. The most stringent requirement is the need for a very compact system with a range of at least 600-700 m. Of course, the optical wavelengths must be in an absolute eye-safe range for humans. A conceptual design of the entire system is described and the most important characteristic of the main elements are provided. In particular the capability of the envisaged laser sources, Nd:YAG and CO2 lasers, to provide the necessary quality of the measurements is carefully assessed. Since the detection of dangerous substances must be performed in an automatic way, the monitoring station will be equipped with an adequate set of control and communication devices for independent autonomous operation. The results of the first preliminary tests illustrate the potential of the chosen approach.

  20. Structurally simple complexes of CO2.

    PubMed

    Murphy, Luke J; Robertson, Katherine N; Kemp, Richard A; Tuononen, Heikki M; Clyburne, Jason A C

    2015-03-07

    The ability to bind CO2 through the formation of low-energy, easily-broken, bonds could prove invaluable in a variety of chemical contexts. For example, weak bonds to CO2 would greatly decrease the cost of the energy-intensive sorbent-regeneration step common to most carbon capture technologies. Furthermore, exploration of this field could lead to the discovery of novel CO2 chemistry. Reduction of complexed carbon dioxide might generate chemical feedstocks for the preparation of value-added products, particularly transportation fuels or fuel precursors. Implementation on a large scale could help to drastically reduce CO2 concentrations in the atmosphere. However, literature examples of weakly bonded complexes of CO2 are relatively few and true coordination complexes to a 'naked' CO2 fragment are nearly unheard of. In this review article, a variety of complexes of CO2 featuring diverse binding modes and reactivity will be examined. Topics covered include: (A) inclusion complexes of CO2 in porous materials. (B) Zwitterionic carbamates produced from the reaction of CO2 with polyamines. (C) Carbamate salts produced from reaction of CO2 with two equivalents of an amine. (D) Insertion products of CO2 into acid-base adducts (e.g., metal complexes). (E) Lewis acid-base activated CO2, such as frustrated Lewis pair complexes. (F) Simple base-CO2 adducts, wherein the base-CO2 bond is the only interaction formed. Complexes in the last category are of particular interest, and include imidazol-2-carboxylates (N-heterocyclic carbene adducts of CO2) as well as a few other examples that lie outside NHC chemistry.

  1. Aminosilicone solvents for CO(2) capture.

    PubMed

    Perry, Robert J; Grocela-Rocha, Teresa A; O'Brien, Michael J; Genovese, Sarah; Wood, Benjamin R; Lewis, Larry N; Lam, Hubert; Soloveichik, Grigorii; Rubinsztajn, Malgorzata; Kniajanski, Sergei; Draper, Sam; Enick, Robert M; Johnson, J Karl; Xie, Hong-bin; Tapriyal, Deepak

    2010-08-23

    This work describes the first report of the use of an aminosilicone solvent mix for the capture of CO(2). To maintain a liquid state, a hydroxyether co-solvent was employed which allowed enhanced physisorption of CO(2) in the solvent mixture. Regeneration of the capture solvent system was demonstrated over 6 cycles and absorption isotherms indicate a 25-50 % increase in dynamic CO(2) capacity over 30 % MEA. In addition, proof of concept for continuous CO(2) absorption was verified. Additionally, modeling to predict heats of reaction of aminosilicone solvents with CO(2) was in good agreement with experimental results.

  2. Isotopic CO2 Instrumentation for UAV Measurements

    NASA Astrophysics Data System (ADS)

    Gomez, A.; Silver, J.

    2013-12-01

    Carbon dioxide is the largest component of anthroprogenic green house gas emissions. Knowing atmospheric 13CO2/12CO2 ratios precisely is important for understanding biogenic and anthroprogenic sources and sinks for carbon. Instrumentation mounted on UAV aircraft would enable important spatial isotopic CO2 information. However, current isotopic CO2 instrumentation have unfavorable attributes for UAV use, such as high power requirements, high cost, high weight, and large size. Here we present the early development of a compact isotopic CO2 instrument that is designed to nullify effects of pressure, temperature and moisture, and will ultimately be suitable for UAV deployment.

  3. Forest succession at elevated CO2

    SciTech Connect

    Clark, James S.; Schlesinger, William H.

    2002-02-01

    We tested hypotheses concerning the response of forest succession to elevated CO2 in the FACTS-1 site at the Duke Forest. We quantified growth and survival of naturally recruited seedlings, tree saplings, vines, and shrubs under ambient and elevated CO2. We planted seeds and seedlings to augment sample sites. We augmented CO2 treatments with estimates of shade tolerance and nutrient limitation while controlling for soil and light effects to place CO2 treatments within the context of natural variability at the site. Results are now being analyzed and used to parameterize forest models of CO2 response.

  4. Microbial Growth under Supercritical CO2

    PubMed Central

    Peet, Kyle C.; Freedman, Adam J. E.; Hernandez, Hector H.; Britto, Vanya; Boreham, Chris; Ajo-Franklin, Jonathan B.

    2015-01-01

    Growth of microorganisms in environments containing CO2 above its critical point is unexpected due to a combination of deleterious effects, including cytoplasmic acidification and membrane destabilization. Thus, supercritical CO2 (scCO2) is generally regarded as a sterilizing agent. We report isolation of bacteria from three sites targeted for geologic carbon dioxide sequestration (GCS) that are capable of growth in pressurized bioreactors containing scCO2. Analysis of 16S rRNA genes from scCO2 enrichment cultures revealed microbial assemblages of varied complexity, including representatives of the genus Bacillus. Propagation of enrichment cultures under scCO2 headspace led to isolation of six strains corresponding to Bacillus cereus, Bacillus subterraneus, Bacillus amyloliquefaciens, Bacillus safensis, and Bacillus megaterium. Isolates are spore-forming, facultative anaerobes and capable of germination and growth under an scCO2 headspace. In addition to these isolates, several Bacillus type strains grew under scCO2, suggesting that this may be a shared feature of spore-forming Bacillus spp. Our results provide direct evidence of microbial activity at the interface between scCO2 and an aqueous phase. Since microbial activity can influence the key mechanisms for permanent storage of sequestered CO2 (i.e., structural, residual, solubility, and mineral trapping), our work suggests that during GCS microorganisms may grow and catalyze biological reactions that influence the fate and transport of CO2 in the deep subsurface. PMID:25681188

  5. Microbial growth under supercritical CO2.

    PubMed

    Peet, Kyle C; Freedman, Adam J E; Hernandez, Hector H; Britto, Vanya; Boreham, Chris; Ajo-Franklin, Jonathan B; Thompson, Janelle R

    2015-04-01

    Growth of microorganisms in environments containing CO2 above its critical point is unexpected due to a combination of deleterious effects, including cytoplasmic acidification and membrane destabilization. Thus, supercritical CO2 (scCO2) is generally regarded as a sterilizing agent. We report isolation of bacteria from three sites targeted for geologic carbon dioxide sequestration (GCS) that are capable of growth in pressurized bioreactors containing scCO2. Analysis of 16S rRNA genes from scCO2 enrichment cultures revealed microbial assemblages of varied complexity, including representatives of the genus Bacillus. Propagation of enrichment cultures under scCO2 headspace led to isolation of six strains corresponding to Bacillus cereus, Bacillus subterraneus, Bacillus amyloliquefaciens, Bacillus safensis, and Bacillus megaterium. Isolates are spore-forming, facultative anaerobes and capable of germination and growth under an scCO2 headspace. In addition to these isolates, several Bacillus type strains grew under scCO2, suggesting that this may be a shared feature of spore-forming Bacillus spp. Our results provide direct evidence of microbial activity at the interface between scCO2 and an aqueous phase. Since microbial activity can influence the key mechanisms for permanent storage of sequestered CO2 (i.e., structural, residual, solubility, and mineral trapping), our work suggests that during GCS microorganisms may grow and catalyze biological reactions that influence the fate and transport of CO2 in the deep subsurface.

  6. Selecting CO2 Sources for CO2 Utilization by Environmental-Merit-Order Curves.

    PubMed

    von der Assen, Niklas; Müller, Leonard J; Steingrube, Annette; Voll, Philip; Bardow, André

    2016-02-02

    Capture and utilization of CO2 as alternative carbon feedstock for fuels, chemicals, and materials aims at reducing greenhouse gas emissions and fossil resource use. For capture of CO2, a large variety of CO2 sources exists. Since they emit much more CO2 than the expected demand for CO2 utilization, the environmentally most favorable CO2 sources should be selected. For this purpose, we introduce the environmental-merit-order (EMO) curve to rank CO2 sources according to their environmental impacts over the available CO2 supply. To determine the environmental impacts of CO2 capture, compression and transport, we conducted a comprehensive literature study for the energy demands of CO2 supply, and constructed a database for CO2 sources in Europe. Mapping these CO2 sources reveals that CO2 transport distances are usually small. Thus, neglecting transport in a first step, we find that environmental impacts are minimized by capturing CO2 first from chemical plants and natural gas processing, then from paper mills, power plants, and iron and steel plants. In a second step, we computed regional EMO curves considering transport and country-specific impacts for energy supply. Building upon regional EMO curves, we identify favorable locations for CO2 utilization with lowest environmental impacts of CO2 supply, so-called CO2 oases.

  7. Educational Materials Development in Primary Science: Dial Thermometer Instructional Unit

    ERIC Educational Resources Information Center

    Franks, Frank L.; Huff, Roger

    1976-01-01

    Described in the fourth of a series of articles dealing with primary science instructional materials for visually handicapped students, is a field test (with 61 Ss in grades 2 to 4) of a dial thermometer instructional unit. (IM)

  8. 18. OPERATOR'S SIDE OF 48' MILL STAND SHOWING DIALS, VERTICAL ...

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

    18. OPERATOR'S SIDE OF 48' MILL STAND SHOWING DIALS, VERTICAL ROLL SCREWDOWN, AND VIEW THROUGH HOUSING TO PINION STAND. Martin Stupich, Photographer, 1989. - U.S. Steel Homestead Works, 48" Plate Mill, Along Monongahela River, Homestead, Allegheny County, PA

  9. Frequency agile OPO-based transmitters for multiwavelength DIAL

    SciTech Connect

    Velsko, S.P.; Ruggiero, A.; Herman, M.

    1996-09-01

    We describe a first generation mid-infrared transmitter with pulse-to- pulse frequency agility and both wide and narrow band capability. This transmitter was used to make multicomponent DIAL measurements in the field.

  10. 47 CFR 51.215 - Dialing parity: Cost recovery.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... (a) A LEC may recover the incremental costs necessary for the implementation of toll dialing parity... may not have a disparate effect on the incremental costs of competing service providers seeking to...

  11. Frequency agile OPO-based transmitters for multiwavelength DIAL

    SciTech Connect

    Velsko, S.P.; Ruggiero, A.; Herman, M.

    1996-09-01

    We describe a first generation mid-infrared transmitter with pulse to pulse frequency agility and both wide and narrow band capability. This transmitter was used to make multicomponent Differential Absorption LIDAR (DIAL) measurements in the field.

  12. Educational Materials Development in Primary Science: Dial Thermometer Instructional Unit

    ERIC Educational Resources Information Center

    Franks, Frank L.; Huff, Roger

    1976-01-01

    Described in the fourth of a series of articles dealing with primary science instructional materials for visually handicapped students, is a field test (with 61 Ss in grades 2 to 4) of a dial thermometer instructional unit. (IM)

  13. 11. EASTERN END OF ZEOLITE BUILDING. NOTE DIAL TO LEFT ...

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

    11. EASTERN END OF ZEOLITE BUILDING. NOTE DIAL TO LEFT OF CLOCK GAUGING TOTAL ZEOLITE INFLUENT IN MILLIONS OF GALLONS PER DAY. - F. E. Weymouth Filtration Plant, 700 North Moreno Avenue, La Verne, Los Angeles County, CA

  14. Amine scrubbing for CO2 capture.

    PubMed

    Rochelle, Gary T

    2009-09-25

    Amine scrubbing has been used to separate carbon dioxide (CO2) from natural gas and hydrogen since 1930. It is a robust technology and is ready to be tested and used on a larger scale for CO2 capture from coal-fired power plants. The minimum work requirement to separate CO2 from coal-fired flue gas and compress CO2 to 150 bar is 0.11 megawatt-hours per metric ton of CO2. Process and solvent improvements should reduce the energy consumption to 0.2 megawatt-hour per ton of CO2. Other advanced technologies will not provide energy-efficient or timely solutions to CO2 emission from conventional coal-fired power plants.

  15. Selection of an averaging technique by simulation study of a DIAL system for toxic agents monitoring

    NASA Astrophysics Data System (ADS)

    Dudeja, Jai Paul; Jindal, Mukesh Kumar; Veerabuthiran, S.

    2007-10-01

    Differential Absorption Lidar (DIAL) is a very effective technique for standoff detection of various toxic agents in the atmosphere. The Lidar backscattered signal received usually has poor signal to noise (SNR) ratio. In order to improve the SNR, statistical averaging over a number of laser pulses is employed. The aim of the present work is to select a particular statistical averaging technique, which is most suitable in removing the noise in Lidar return signals. The DIAL system considered here uses laser transmitters based on OPO based (2-5 μm) and TEA CO2 (9-11μm) lasers. Eight commonly used chemical warfare agents including five nerve agents and three blister agents have been considered here as examples of toxic agents. A Graphical User Interface (GUI) software has been developed in LabVIEW to simulate return signals mixed with the expected noise levels. A toxic agent cloud with a given thickness and concentration has been assumed to be detected in the ambient atmospheric conditions at various ranges up to 5 Km. Data for 200 pulses per agent was stored in the computer memory. Various known statistical averaging techniques were used and number concentrations of particular agent have been computed and compared with ideal Lidar return signal values. This exercise was repeated for all the eight agents and based on the results obtained; the most suitable averaging technique has been selected.

  16. Comparison of 2 micron Ho and 10 micron CO2 lidar for atmospheric backscatter and Doppler windshear detection

    NASA Technical Reports Server (NTRS)

    Killinger, Dennis

    1991-01-01

    The development of eye-safe, solid-state Lidar systems is discussed, with an emphasis on Coherent Doppler Lidar for Atmospheric Wind Measurements. The following subject areas are covered: tunable Ho DIAL (Differential Absorption Lidar)/lidar atmospheric measurements; atmospheric turbulence measurements and detector arrays; diurnal measurements of C(sub n)(sup 2) for KSC lidar measurements; and development of single-frequency Ho laser/lidar.

  17. CO2 lasers: beam patterns in relation to surgical use.

    PubMed

    Fava, G; Emanuelli, H; Cascinelli, N; Bandieramonte, G; Canestri, F; Marchesini, R

    1983-01-01

    According to surgeons operating with a variety of CO2 lasers available at the National Cancer Institute of Milan (Coherent, Sharplan, Valfivre), these lasers have different cutting and coagulation properties. To identify what physical parameters might corroborate the subjective impression of the surgeons, a comparative study of the crater forms in perspex samples was performed. Perspex was chosen for its thermal properties (in fact, its thermal conductivity and diffusivity are similar to those of organic tissue) and because it allowed good visualization and measurement of crater characteristics. Depth of penetration, crater diameter, and extension of thermal damage were measured against power, focal length, and exposure time for each CO2 laser model. These results can be used as an index of behaviour of different surgical lasers. It appears that for fully characterizing the interaction of surgical lasers with the sample, it is necessary to specify either power, focal length, exposure time, or beam mode.

  18. Overview of the CALIOPE CO{sub 2} DIAL Project

    SciTech Connect

    Schultz, J.

    1997-08-01

    During 1996 the CALIOPE CO{sub 2} DIAL Project developed a new generation of lidar transmitter, receiver, data acquisition, and control technology, constructed new ground and airborne lidar systems, and used them to conduct extensive field tests. New data analysis algorithms were successfully applied to the test data, and CO{sub 2} DIAL capabilities were significantly improved. Recent activities and accomplishments are summarized, and future directions are discussed.

  19. Fourier Transform Microwave Spectra of CO{2}-ETHYLENE Sulfide, CO{2}-ETHYLENE Oxide and CO{2}-PROPYLENE Oxide Complexes

    NASA Astrophysics Data System (ADS)

    Orita, Yukari; Kawashima, Yoshiyuki; Hirota, Eizi

    2010-06-01

    We have previously examined the difference in roles of O and S in structure and dynamics of the CO-ethylene oxide (EO) and CO-ethylene sulfide (ES) complexes. We have extended the investigation to CO{2}-EO and CO{2}-ES for comparison. We have also observed the CO{2}-propylene oxide (PO) complex, which is an important intermediate in the reaction of PO with CO{2} leading to polycarbonate. Both a-type and b-type transitions were observed for the CO{2}-EO and CO{2}-ES, but no c-type transitions were observed at all. We also detected the {34}S and {13}C isotopic species in natural abundance and the species containing {18}OCO and C{18}O% {2}, which were synthesized by burning paper in an {18}O{2} and{% 16}O{2} mixture. By analyzing the observed spectra we concluded the CO{2} moiety of CO{2}-EO and CO{2}-ES located in a plane % prependicular to the three-membered ring and bisecting the COC or CSC angle of EO or ES, respectively, as in the case of CO-EO and CO-ES complexes. An % ab initio MO calculation at the level of MP2/6-311G(d, p) yielded an optimized structure in good agreement with the experimental result. We have derived from the observed spectra the distance, the stretching force constant, and the binding energy of the bonds between the constituents of the CO{2}-EO and CO{2}-ES complexes and have found that the distances of the two complexes were shorter by 0.2Å than those in CO-EO and CO-ES, respectively, and that the intermolecular bonds were two times stronger in the CO{2} complexes than in the corresponding CO complexes. We have concluded from the observed spectra that the CO{2} moiety in CO{2}-PO is located on the PO three-membered ring plane opposite to the methyl group. The constituents in CO{2}-PO were more weakly bound than those in CO{2}-EO and CO{2}-ES. S. Sato, Y. Kawashima, Y. Tatamitani, and E. Hirota, 63rd International Symposium on Molecular Spectroscopy, WF05 (2008).

  20. Advanced Detector and Waveform Digitizer for Water Vapor DIAL Systems

    NASA Technical Reports Server (NTRS)

    Refaat, Tamer F.; Luck, William S., Jr.; DeYoung, Russell J.

    1998-01-01

    Measurement of atmospheric water vapor has become a major requirement for understanding moist-air processes. Differential absorption lidar (DIAL) is a technique best suited for the measurement of atmospheric water vapor. NASA Langley Research Center is continually developing improved DIAL systems. One aspect of current development is focused on the enhancement of a DIAL receiver by applying state-of-the-art technology in building a new compact detection system that will be placed directly on the DIAL receiver telescope. The newly developed detection system has the capability of being digitally interfaced with a simple personal computer, using a discrete input/output interface. This has the potential of transmitting digital data over relatively long distances instead of analog signals, which greatly reduces measurement noise. In this paper, we discuss some results from the new compact water vapor DIAL detection system which includes a silicon based avalanche photodiode (APD) detector, a 14-bit, 10-MHz waveform digitizer, a microcontroller and other auxiliary electronics. All of which are contained on a small printed-circuit-board. This will significantly reduce the weight and volume over the current CAMAC system and eventually will be used in a water vapor DIAL system on an unpiloted atmospheric vehicle (UAV) aircraft, or alternatively on an orbiting spacecraft.

  1. Setting up a mobile Lidar (DIAL) system for detecting chemical warfare agents

    NASA Astrophysics Data System (ADS)

    Kavosh Tehrani, M.; Mohammad, M. Malek; Jaafari, E.; Mobashery, A.

    2015-03-01

    The mobile light detection and ranging DIAL system of Malek Ashtar University of Technology has been developed for the detection of chemical warfare agents whose absorption wavelengths are in the range of 9.2-10.8 μm tunable CO2 lasers of the system. In this paper, this system is first described and then ammonia detection is analyzed experimentally. Also, experimental results of detecting a sarin agent simulant, dimethyl-methyl phosphonate (DMMP), are presented. The power levels received from different ranges to detect specific concentrations of NH3 and DMMP have been measured and debated. The primary test results with a 150 ns clipped pulse width by passive pinhole plasma shutter indicate that the system is capable of monitoring several species of pollutants in the range of about 1 km, with a 20 m spatial and 2 min temporal resolution.

  2. Variability in soil CO2 production and surface CO2 efflux across riparian-hillslope transitions

    Treesearch

    Vincent Jerald. Pacific

    2007-01-01

    The spatial and temporal controls on soil CO2 production and surface CO2 efflux have been identified as an outstanding gap in our understanding of carbon cycling. I investigated both the spatial and temporal variability of soil CO2 concentrations and surface CO2 efflux across eight topographically distinct riparian-hillslope transitions in the ~300 ha subalpine upper-...

  3. All-fiber versatile laser frequency reference at 2 μm for CO2 space-borne lidar applications

    NASA Astrophysics Data System (ADS)

    Schilt, Stéphane; Matthey, Renaud; Hey Tow, Kenny; Thévenaz, Luc; Südmeyer, Thomas

    2017-06-01

    We present a frequency stabilized laser at 2051 nm based on a versatile all-fibered stabilization setup. A modulation sideband locking technique is implemented to lock the laser at a controlled frequency detuning from the center of the CO2 R(30) transition envisaged for space-borne differential absorption lidar (DIAL) applications. This method relies on the use of a compact all-fibered gas reference cell that makes the setup robust and immune to mechanically induced optical misalignments. The gas cell is fabricated using a hollow-core photonic crystal fiber filled with pure CO2 at a low pressure of 20 mbar and hermetically sealed at both ends by splices to silica fibers. Different configurations of this fibered cell have been developed and are presented. With this technique, frequency stabilities below 40 kHz at 1-s integration time and <100 kHz up to 1000-s averaging time were achieved for a laser detuning by around 1 GHz from the center of the CO2 transition. These stabilities are compliant with typical requirements for the reference seed source for a space CO2 DIAL.

  4. CO2 transport over complex terrain

    USGS Publications Warehouse

    Sun, Jielun; Burns, Sean P.; Delany, A.C.; Oncley, S.P.; Turnipseed, A.A.; Stephens, B.B.; Lenschow, D.H.; LeMone, M.A.; Monson, Russell K.; Anderson, D.E.

    2007-01-01

    CO2 transport processes relevant for estimating net ecosystem exchange (NEE) at the Niwot Ridge AmeriFlux site in the front range of the Rocky Mountains, Colorado, USA, were investigated during a pilot experiment. We found that cold, moist, and CO2-rich air was transported downslope at night and upslope in the early morning at this forest site situated on a ???5% east-facing slope. We found that CO2 advection dominated the total CO2 transport in the NEE estimate at night although there are large uncertainties because of partial cancellation of horizontal and vertical advection. The horizontal CO2 advection captured not only the CO2 loss at night, but also the CO2 uptake during daytime. We found that horizontal CO2 advection was significant even during daytime especially when turbulent mixing was not significant, such as in early morning and evening transition periods and within the canopy. Similar processes can occur anywhere regardless of whether flow is generated by orography, synoptic pressure gradients, or surface heterogeneity as long as CO2 concentration is not well mixed by turbulence. The long-term net effect of all the CO2 budget terms on estimates of NEE needs to be investigated. ?? 2007 Elsevier B.V. All rights reserved.

  5. Covalent Organic Frameworks for CO2 Capture.

    PubMed

    Zeng, Yongfei; Zou, Ruqiang; Zhao, Yanli

    2016-04-20

    As an emerging class of porous crystalline materials, covalent organic frameworks (COFs) are excellent candidates for various applications. In particular, they can serve as ideal platforms for capturing CO2 to mitigate the dilemma caused by the greenhouse effect. Recent research achievements using COFs for CO2 capture are highlighted. A background overview is provided, consisting of a brief statement on the current CO2 issue, a summary of representative materials utilized for CO2 capture, and an introduction to COFs. Research progresses on: i) experimental CO2 capture using different COFs synthesized based on different covalent bond formations, and ii) computational simulation results of such porous materials on CO2 capture are summarized. Based on these experimental and theoretical studies, careful analyses and discussions in terms of the COF stability, low- and high-pressure CO2 uptake, CO2 selectivity, breakthrough performance, and CO2 capture conditions are provided. Finally, a perspective and conclusion section of COFs for CO2 capture is presented. Recent advancements in the field are highlighted and the strategies and principals involved are discussed.

  6. CO2 flux from Javanese mud volcanism.

    PubMed

    Queißer, M; Burton, M R; Arzilli, F; Chiarugi, A; Marliyani, G I; Anggara, F; Harijoko, A

    2017-06-01

    Studying the quantity and origin of CO2 emitted by back-arc mud volcanoes is critical to correctly model fluid-dynamical, thermodynamical, and geochemical processes that drive their activity and to constrain their role in the global geochemical carbon cycle. We measured CO2 fluxes of the Bledug Kuwu mud volcano on the Kendeng Fold and thrust belt in the back arc of Central Java, Indonesia, using scanning remote sensing absorption spectroscopy. The data show that the expelled gas is rich in CO2 with a volume fraction of at least 16 vol %. A lower limit CO2 flux of 1.4 kg s(-1) (117 t d(-1)) was determined, in line with the CO2 flux from the Javanese mud volcano LUSI. Extrapolating these results to mud volcanism from the whole of Java suggests an order of magnitude total CO2 flux of 3 kt d(-1), comparable with the expected back-arc efflux of magmatic CO2. After discussing geochemical, geological, and geophysical evidence we conclude that the source of CO2 observed at Bledug Kuwu is likely a mixture of thermogenic, biogenic, and magmatic CO2, with faulting controlling potential pathways for magmatic fluids. This study further demonstrates the merit of man-portable active remote sensing instruments for probing natural gas releases, enabling bottom-up quantification of CO2 fluxes.

  7. Earth's Atmospheric CO2 Saturated IR Absorption

    NASA Astrophysics Data System (ADS)

    Wall, Ernst

    2008-10-01

    Using the on-line SpectraCalc IR absorption simulator, the amount of IR absorption by the 15 μ line of the current atmospheric CO2 was obtained and compared with that of twice the amount of CO2. The simulation required a fixed density equivalent for the atmospheric path length. This was obtained by numerically integrating the NOAA Standard Atmospheric model. While the current line is saturated, doubling the CO2 will cause a slight width increase. Using this and the blackbody radiation curve plus considering the effects of water vapor, the temperature rise of the Earth will be less than 2.5 deg. C. Integrating a NASA Martian atmospheric model, we find that the Martian atmosphere has 45 times more CO2 to penetrate than Earth, and yet, the Martian diurnal temperature swings exceed those of the Sahara desert. I.e., large amounts of CO2 alone do not necessarily cause planetary warming. As the oceans warm from any cause, more CO2 is boiled out, but if they cool, they will absorb more CO2 just as a carbonated drink does, so that temperature and CO2 density will correlate. It is to be noted that the Earth's known petroleum reserves contain only enough CO2 to increase the atmospheric CO2 by some 15%.

  8. CO2 flux from Javanese mud volcanism

    NASA Astrophysics Data System (ADS)

    Queißer, M.; Burton, M. R.; Arzilli, F.; Chiarugi, A.; Marliyani, G. I.; Anggara, F.; Harijoko, A.

    2017-06-01

    Studying the quantity and origin of CO2 emitted by back-arc mud volcanoes is critical to correctly model fluid-dynamical, thermodynamical, and geochemical processes that drive their activity and to constrain their role in the global geochemical carbon cycle. We measured CO2 fluxes of the Bledug Kuwu mud volcano on the Kendeng Fold and thrust belt in the back arc of Central Java, Indonesia, using scanning remote sensing absorption spectroscopy. The data show that the expelled gas is rich in CO2 with a volume fraction of at least 16 vol %. A lower limit CO2 flux of 1.4 kg s-1 (117 t d-1) was determined, in line with the CO2 flux from the Javanese mud volcano LUSI. Extrapolating these results to mud volcanism from the whole of Java suggests an order of magnitude total CO2 flux of 3 kt d-1, comparable with the expected back-arc efflux of magmatic CO2. After discussing geochemical, geological, and geophysical evidence we conclude that the source of CO2 observed at Bledug Kuwu is likely a mixture of thermogenic, biogenic, and magmatic CO2, with faulting controlling potential pathways for magmatic fluids. This study further demonstrates the merit of man-portable active remote sensing instruments for probing natural gas releases, enabling bottom-up quantification of CO2 fluxes.

  9. CO2 flux from Javanese mud volcanism

    PubMed Central

    Burton, M. R.; Arzilli, F.; Chiarugi, A.; Marliyani, G. I.; Anggara, F.; Harijoko, A.

    2017-01-01

    Abstract Studying the quantity and origin of CO2 emitted by back‐arc mud volcanoes is critical to correctly model fluid‐dynamical, thermodynamical, and geochemical processes that drive their activity and to constrain their role in the global geochemical carbon cycle. We measured CO2 fluxes of the Bledug Kuwu mud volcano on the Kendeng Fold and thrust belt in the back arc of Central Java, Indonesia, using scanning remote sensing absorption spectroscopy. The data show that the expelled gas is rich in CO2 with a volume fraction of at least 16 vol %. A lower limit CO2 flux of 1.4 kg s−1 (117 t d−1) was determined, in line with the CO2 flux from the Javanese mud volcano LUSI. Extrapolating these results to mud volcanism from the whole of Java suggests an order of magnitude total CO2 flux of 3 kt d−1, comparable with the expected back‐arc efflux of magmatic CO2. After discussing geochemical, geological, and geophysical evidence we conclude that the source of CO2 observed at Bledug Kuwu is likely a mixture of thermogenic, biogenic, and magmatic CO2, with faulting controlling potential pathways for magmatic fluids. This study further demonstrates the merit of man‐portable active remote sensing instruments for probing natural gas releases, enabling bottom‐up quantification of CO2 fluxes. PMID:28944134

  10. Analysis of intrapulse chirp in CO2 oscillators

    NASA Technical Reports Server (NTRS)

    Moody, Stephen E.; Berger, Russell G.; Thayer, William J., III

    1987-01-01

    Pulsed single-frequency CO2 laser oscillators are often used as transmitters for coherent lidar applications. These oscillators suffer from intrapulse chirp, or dynamic frequency shifting. If excessive, such chirp can limit the signal-to-noise ratio of the lidar (by generating excess bandwidth), or limit the velocity resolution if the lidar is of the Doppler type. This paper describes a detailed numerical model that considers all known sources of intrapulse chirp. Some typical predictions of the model are shown, and simple design rules to minimize chirp are proposed.

  11. Exogenously produced CO2 doubles the CO2 efflux from three north temperate lakes

    NASA Astrophysics Data System (ADS)

    Wilkinson, Grace M.; Buelo, Cal D.; Cole, Jonathan J.; Pace, Michael L.

    2016-03-01

    It is well established that lakes are typically sources of CO2 to the atmosphere. However, it remains unclear what portion of CO2 efflux is from endogenously processed organic carbon or from exogenously produced CO2 transported into lakes. We estimated high-frequency CO2 and O2 efflux from three north temperate lakes in summer to determine the proportion of the total CO2 efflux that was exogenously produced. Two of the lakes were amended with nutrients to experimentally enhance endogenous CO2 uptake. In the unfertilized lake, 50% of CO2 efflux was from exogenous sources and hydrology had a large influence on efflux. In the fertilized lakes, endogenous CO2 efflux was negative (into the lake) yet exogenous CO2 made the lakes net sources of CO2 to the atmosphere. Shifts in hydrologic regimes and nutrient loading have the potential to change whether small lakes act primarily as reactors or vents in the watershed.

  12. Different CO2 absorbents-modified SBA-15 sorbent for highly selective CO2 capture

    NASA Astrophysics Data System (ADS)

    Liu, Xiuwu; Zhai, Xinru; Liu, Dongyang; Sun, Yan

    2017-05-01

    Different CO2 absorbents-modified SBA-15 materials are used as CO2 sorbent to improve the selectivity of CH4/CO2 separation. The SBA-15 sorbents modified by physical CO2 absorbents are very limited to increasing CO2 adsorption and present poor selectivity. However, the SBA-15 sorbents modified by chemical CO2 absorbents increase CO2 adsorption capacity obviously. The separation coefficients of CO2/CH4 increase in this case. The adsorption and regeneration properties of the SBA-15 sorbents modified by TEA, MDEA and DIPA have been compared. The SBA-15 modified by triethanolamine (TEA) presents better CO2/CH4 separation performance than the materials modified by other CO2 absorbents.

  13. Energyless CO2 Absorption, Generation, and Fixation Using Atmospheric CO2.

    PubMed

    Inagaki, Fuyuhiko; Okada, Yasuhiko; Matsumoto, Chiaki; Yamada, Masayuki; Nakazawa, Kenta; Mukai, Chisato

    2016-01-01

    From an economic and ecological perspective, the efficient utilization of atmospheric CO2 as a carbon resource should be a much more important goal than reducing CO2 emissions. However, no strategy to harvest CO2 using atmospheric CO2 at room temperature currently exists, which is presumably due to the extremely low concentration of CO2 in ambient air (approximately 400 ppm=0.04 vol%). We discovered that monoethanolamine (MEA) and its derivatives efficiently absorbed atmospheric CO2 without requiring an energy source. We also found that the absorbed CO2 could be easily liberated with acid. Furthermore, a novel CO2 generator enabled us to synthesize a high value-added material (i.e., 2-oxazolidinone derivatives based on the metal catalyzed CO2-fixation at room temperature) from atmospheric CO2.

  14. Stabilities and structures of the Li-CO 2 and Na-CO 2 complexes

    NASA Astrophysics Data System (ADS)

    Yoshioka, Y.; Jordan, K. D.

    1981-12-01

    The geometries and stabilities of the Li-CO 2 and Na-CO 2 complexes are calculated using thc self-consistent-field-XXX-Fock method. The minimum energy. C 2v structures of Li-CO 2 and Na-CO 2 are found to be stable by 0.85 and 0.34 eV, respectively, with respect to dissociation to CO 2 + alkali atom.

  15. CO2 sequestration: Storage capacity guideline needed

    USGS Publications Warehouse

    Frailey, S.M.; Finley, R.J.; Hickman, T.S.

    2006-01-01

    Petroleum reserves are classified for the assessment of available supplies by governmental agencies, management of business processes for achieving exploration and production efficiency, and documentation of the value of reserves and resources in financial statements. Up to the present however, the storage capacity determinations made by some organizations in the initial CO2 resource assessment are incorrect technically. New publications should thus cover differences in mineral adsorption of CO2 and dissolution of CO2 in various brine waters.

  16. Radium dial watches, a potentially hazardous legacy?

    PubMed

    Gillmore, Gavin K; Crockett, Robin; Denman, Tony; Flowers, Alan; Harris, Richard

    2012-09-15

    This study re-examines the risk to health from radium ((226)Ra) dial watches. Ambient dose equivalent rates have been measured for fifteen pocket watches giving results of up to 30 μSv h(-1) at a distance of 2 cm taken with a series 1000 mini-rad from the front face (arithmetic mean ambient dose equivalent for pocket watches being 13.2 μSv h(-1)). A pocket compass gave rise to a similar ambient dose equivalent rate, of 20 μSv h(-1), to the pocket watches, with its cover open. Eighteen wristwatches have also been assessed, but their dose rates are generally much lower (the arithmetic mean being 3.0 μSv h(-1)), although the highest ambient dose equivalent rate noted was 20 μSv h(-1). A phantom experiment using a TLD suggested an effective dose equivalent of 2.2 mSv/y from a 1 μCi (37 kBq) radium dial worn for 16 h/day throughout the year (dose rate 0.375 μSv h(-1)). For this condition we estimated maximum skin dose for our pocket watches as 16 mSv per year, with effective doses of 5.1 mSv and 1.169 mSv when worn in vest and trouser pockets respectively. This assumes exposure from the back of the watch which is generally around 60-67% of that from the front. The maximum skin dose from a wristwatch was 14 mSv, with 4.2 mSv effective dose in vest pocket. Radium ((226)Ra) decays to the radioactive gas radon ((222)Rn), and atmospheric radon concentration measurements taken around a pocket watch in a small sealed glass sphere recorded 18,728 B qm(-3). All watches were placed in a room with a RAD7 real-time radon detector. Radon concentration average was 259±9 Bq m(-3) over 16 h, compared to background average over 24h of 1.02 Bq m(-3). Over 6 weeks highs of the order of 2000 Bq m(-3) were routinely recorded when the heating/ventilation system in the room was operating at reduced rates, peaking at over 3000 Bq m(-3) on several occasions. Estimates of the activity of (226)Ra in the watches ranged from 0.063 to 1.063 μCi (2.31 to 39.31 kBq) for pocket watches and

  17. CO2 capture in different carbon materials.

    PubMed

    Jiménez, Vicente; Ramírez-Lucas, Ana; Díaz, José Antonio; Sánchez, Paula; Romero, Amaya

    2012-07-03

    In this work, the CO(2) capture capacity of different types of carbon nanofibers (platelet, fishbone, and ribbon) and amorphous carbon have been measured at 26 °C as at different pressures. The results showed that the more graphitic carbon materials adsorbed less CO(2) than more amorphous materials. Then, the aim was to improve the CO(2) adsorption capacity of the carbon materials by increasing the porosity during the chemical activation process. After chemical activation process, the amorphous carbon and platelet CNFs increased the CO(2) adsorption capacity 1.6 times, whereas fishbone and ribbon CNFs increased their CO(2) adsorption capacity 1.1 and 8.2 times, respectively. This increase of CO(2) adsorption capacity after chemical activation was due to an increase of BET surface area and pore volume in all carbon materials. Finally, the CO(2) adsorption isotherms showed that activated amorphous carbon exhibited the best CO(2) capture capacity with 72.0 wt % of CO(2) at 26 °C and 8 bar.

  18. R&D100: CO2 Memzyme

    ScienceCinema

    Rempe, Susan; Brinker, Jeff; Jiang, Ying-Bing; Vanegas, Juan

    2016-07-12

    By combining a water droplet loaded with CO2 enzymes in an ultrathin nanopore on a flexible substrate, researchers at Sandia National Laboratories realized the first technology that meets and exceeds DOE targets for cost-effective CO2 capture. When compared with the nearest membrane competitor, this technology delivers a three times permeation rate, twenty times higher selectivity, and ten time lower fabrication cost. The CO2 Memzyme has the potential to remove 90% of CO2 emissions and is forecasted to save the U.S. coal industry $90 billion a year compared to conventional technology.

  19. Synthetic biology for CO2 fixation.

    PubMed

    Gong, Fuyu; Cai, Zhen; Li, Yin

    2016-11-01

    Recycling of carbon dioxide (CO2) into fuels and chemicals is a potential approach to reduce CO2 emission and fossil-fuel consumption. Autotrophic microbes can utilize energy from light, hydrogen, or sulfur to assimilate atmospheric CO2 into organic compounds at ambient temperature and pressure. This provides a feasible way for biological production of fuels and chemicals from CO2 under normal conditions. Recently great progress has been made in this research area, and dozens of CO2-derived fuels and chemicals have been reported to be synthesized by autotrophic microbes. This is accompanied by investigations into natural CO2-fixation pathways and the rapid development of new technologies in synthetic biology. This review first summarizes the six natural CO2-fixation pathways reported to date, followed by an overview of recent progress in the design and engineering of CO2-fixation pathways as well as energy supply patterns using the concept and tools of synthetic biology. Finally, we will discuss future prospects in biological fixation of CO2.

  20. R&D100: CO2 Memzyme

    SciTech Connect

    Rempe, Susan; Brinker, Jeff; Jiang, Ying-Bing; Vanegas, Juan

    2015-11-19

    By combining a water droplet loaded with CO2 enzymes in an ultrathin nanopore on a flexible substrate, researchers at Sandia National Laboratories realized the first technology that meets and exceeds DOE targets for cost-effective CO2 capture. When compared with the nearest membrane competitor, this technology delivers a three times permeation rate, twenty times higher selectivity, and ten time lower fabrication cost. The CO2 Memzyme has the potential to remove 90% of CO2 emissions and is forecasted to save the U.S. coal industry $90 billion a year compared to conventional technology.

  1. CO2 MITIGATION VIA ACCELERATED LIMESTONE WEATHERING

    SciTech Connect

    Rau, G H; Knauss, K G; Langer, W H; Caldeira, K G

    2004-02-27

    The climate and environmental impacts of our current, carbon-intensive energy usage demands that effective and practical energy alternatives and CO2 mitigation strategies be found. As part of this effort, various means of capturing and storing CO2 generated from fossil-fuel-based energy production are being investigated. One of the proposed methods involves a geochemistry-based capture and sequestration process that hydrates point-source, waste CO2 with water to produce a carbonic acid solution. This in turn is reacted and neutralized with limestone, thus converting the original CO2 gas to calcium bicarbonate in solution, the overall reaction being:

  2. CO2 Interaction with Geomaterials (Invited)

    NASA Astrophysics Data System (ADS)

    Romanov, V.; Howard, B. H.; Lynn, R. J.; Warzinski, R. P.; Hur, T.; Myshakin, E. M.; Lopano, C. L.; Voora, V. K.; Al-Saidi, W. A.; Jordan, K. D.; Cygan, R. T.; Guthrie, G. D.

    2010-12-01

    This work compares the sorption and swelling processes associated with CO2-coal and CO2-clay interactions. We investigated the mechanisms of interaction related to CO2 adsortion in micropores, intercalation into sub-micropores, dissolution in solid matrix, the role of water, and the associated changes in reservoir permeability, for applications in CO2 sequestration and enhanced coal bed methane recovery. The structural changes caused by CO2 have been investigated. A high-pressure micro-dilatometer was equipped to investigate the effect of CO2 pressure on the thermoplastic properties of coal. Using an identical dilatometer, Rashid Khan (1985) performed experiments with CO2 that revealed a dramatic reduction in the softening temperature of coal when exposed to high-pressure CO2. A set of experiments was designed for -20+45-mesh samples of Argonne Premium Pocahontas #3 coal, which is similar in proximate and ultimate analysis to the Lower Kittanning seam coal that Khan used in his experiments. No dramatic decrease in coal softening temperature has been observed in high-pressure CO2 that would corroborate the prior work of Khan. Thus, conventional polymer (or “geopolymer”) theories may not be directly applicable to CO2 interaction with coals. Clays are similar to coals in that they represent abundant geomaterials with well-developed microporous structure. We evaluated the CO2 sequestration potential of clays relative to coals and investigated the factors that affect the sorption capacity, rates, and permanence of CO2 trapping. For the geomaterials comparison studies, we used source clay samples from The Clay Minerals Society. Preliminary results showed that expandable clays have CO2 sorption capacities comparable to those of coal. We analyzed sorption isotherms, XRD, DRIFTS (infrared reflectance spectra at non-ambient conditions), and TGA-MS (thermal gravimetric analysis) data to compare the effects of various factors on CO2 trapping. In montmorillonite, CO2

  3. CO2 generation rate in Chinese people.

    PubMed

    Qi, M W; Li, X F; Weschler, L B; Sundell, J

    2014-12-01

    Carbon dioxide (CO2 ) metabolically produced by humans has been widely used as a tracer gas for determining ventilation rates in occupied rooms. Among other necessities, the method requires good estimates of human CO2 generation rates. An empirically derived equation is widely used to calculate the CO2 generation rate. However, there are indications that this equation is not valid for young Chinese people. In this study, we measured the CO2 generation rate of 44 young Chinese people at two typical activity levels, quiet sitting and relaxed standing. We found that the commonly used empirical equation overpredicted CO2 generation rates, but could be corrected with a factor of 0.75 for Chinese females and of 0.85 for Chinese males. The variance for measured CO2 sitting was much smaller than for standing, and hence, we concluded that sitting yields more precise CO2 generation estimates. The relative contributions of sex, height, weight, and metabolic rate were analyzed. We concluded that the error in estimating metabolic rate is responsible for most of the difference in measured generation of CO2 from the empirical equation's predictions. The tracer gas method using CO2 generated by people is widely used to calculate ventilation rate. However, the empirically derived equation that is normally used to estimate CO2 generation rate is not suitable for young Chinese people at rest. To estimate the CO2 generation rate in Chinese people under low-activity conditions, the empirical equation should be multiplied by correction factors of 0.75 and 0.85 for females and males, respectively. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. CO2 Capture with Enzyme Synthetic Analogue

    SciTech Connect

    Cordatos, Harry

    2010-11-08

    Overview of an ongoing, 2 year research project partially funded by APRA-E to create a novel, synthetic analogue of carbonic anhydrase and incorporate it into a membrane for removal of CO2 from flue gas in coal power plants. Mechanism background, preliminary feasibility study results, molecular modeling of analogue-CO2 interaction, and program timeline are provided.

  5. CO2 Capture with Enzyme Synthetic Analogue

    SciTech Connect

    Cordatos, Harry

    2010-03-01

    Project overview provides background on carbonic anhydrase transport mechanism for CO2 in the human body and proposed approach for ARPA-E project to create a synthetic enzyme analogue and utilize it in a membrane for CO2 capture from flue gas.

  6. Capturing CO2 via reactions in nanopores.

    SciTech Connect

    Leung, Kevin; Nenoff, Tina Maria; Criscenti, Louise Jacqueline; Tang, Z; Dong, J. H.

    2008-10-01

    This one-year exploratory LDRD aims to provide fundamental understanding of the mechanism of CO2 scrubbing platforms that will reduce green house gas emission and mitigate the effect of climate change. The project builds on the team members expertise developed in previous LDRD projects to study the capture or preferential retention of CO2 in nanoporous membranes and on metal oxide surfaces. We apply Density Functional Theory and ab initio molecular dynamics techniques to model the binding of CO2 on MgO and CaO (100) surfaces and inside water-filled, amine group functionalized silica nanopores. The results elucidate the mechanisms of CO2 trapping and clarify some confusion in the literature. Our work identifies key future calculations that will have the greatest impact on CO2 capture technologies, and provides guidance to science-based design of platforms that can separate the green house gas CO2 from power plant exhaust or even from the atmosphere. Experimentally, we modify commercial MFI zeolite membranes and find that they preferentially transmit H2 over CO2 by a factor of 34. Since zeolite has potential catalytic capability to crack hydrocarbons into CO2 and H2, this finding paves the way for zeolite membranes that can convert biofuel into H2 and separate the products all in one step.

  7. Improved Criteria for Increasing CO2 Storage Potential with CO2 Enhanced Oil Recovery

    NASA Astrophysics Data System (ADS)

    Bauman, J.; Pawar, R.

    2013-12-01

    In recent years it has been found that deployment of CO2 capture and storage technology at large scales will be difficult without significant incentives. One of the technologies that has been a focus in recent years is CO2 enhanced oil/gas recovery, where additional hydrocarbon recovery provides an economic incentive for deployment. The way CO2 EOR is currently deployed, maximization of additional oil production does not necessarily lead to maximization of stored CO2, though significant amounts of CO2 are stored regardless of the objective. To determine the potential of large-scale CO2 storage through CO2 EOR, it is necessary to determine the feasibility of deploying this technology over a wide range of oil/gas field characteristics. In addition it is also necessary to accurately estimate the ultimate CO2 storage potential and develop approaches that optimize oil recovery along with long-term CO2 storage. This study uses compositional reservoir simulations to further develop technical screening criteria that not only improve oil recovery, but maximize CO2 storage during enhanced oil recovery operations. Minimum miscibility pressure, maximum oil/ CO2 contact without the need of significant waterflooding, and CO2 breakthrough prevention are a few key parameters specific to the technical aspects of CO2 enhanced oil recovery that maximize CO2 storage. We have developed reduced order models based on simulation results to determine the ultimate oil recovery and CO2 storage potential in these formations. Our goal is to develop and demonstrate a methodology that can be used to determine feasibility and long-term CO2 storage potential of CO2 EOR technology.

  8. Zinc depolarized electrochemical CO2 concentration

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

    Two zinc depolarized electrochemical carbon dioxide concentrator concepts were analytically and experimentally evaluated for portable life support system carbon dioxide (CO2) removal application. The first concept, referred to as the zinc hydrogen generator electrochemical depolarized CO2 concentrator, uses a ZHG to generate hydrogen for direct use in an EDC. The second concept, referred to as the zinc/electrochemical depolarized concentrator, uses a standard EDC cell construction modified for use with the Zn anode. The Zn anode is consumed and subsequently regenerated, thereby eliminating the need to supply H2 to the EDC for the CO2 removal process. The evaluation was based primarily on an analytical evaluation of the two ZnDCs at projected end item performance and hardware design levels. Both ZnDC concepts for PLSS CO2 removal application were found to be noncompetitive in both total equivalent launch weight and individual extravehicular activity mission volume when compared to other candidate regenerable PLSS CO2 scrubbers.

  9. Underwater CO2 Sequestration Program in Korea

    NASA Astrophysics Data System (ADS)

    Kang, S.; Park, Y.; Choi, S.; Kim, Y.; Hwang, J.; Lee, J.

    2008-12-01

    In Korea an interdisciplinary project on underwater CO2 sequestration has been started. One of the main potential sites for the sequestration is the "DolGoRae (Dolphin)" gas field located over the southwestern part of the East/Japan Sea. We plan to deliver CO2 captured from the largest steel company in Korea (POSCO) to this site through pipe lines. To meet this end, chemical engineers study the behavior of CO2 hydrates, mechanical engineers design the pipe lines and injection systems, geologists and geological engineers survey the geological structure of the potential sites, and oceanographers assess the environmental effects. From a preliminary study, we find that we can store captured CO2 to the gas filed safely. In case the CO2 leaks from the storage site it would move to the north along the Korean coast on the average.

  10. Geophysical monitoring technology for CO2 sequestration

    NASA Astrophysics Data System (ADS)

    Ma, Jin-Feng; Li, Lin; Wang, Hao-Fan; Tan, Ming-You; Cui, Shi-Ling; Zhang, Yun-Yin; Qu, Zhi-Peng; Jia, Ling-Yun; Zhang, Shu-Hai

    2016-06-01

    Geophysical techniques play key roles in the measuring, monitoring, and verifying the safety of CO2 sequestration and in identifying the efficiency of CO2-enhanced oil recovery. Although geophysical monitoring techniques for CO2 sequestration have grown out of conventional oil and gas geophysical exploration techniques, it takes a long time to conduct geophysical monitoring, and there are many barriers and challenges. In this paper, with the initial objective of performing CO2 sequestration, we studied the geophysical tasks associated with evaluating geological storage sites and monitoring CO2 sequestration. Based on our review of the scope of geophysical monitoring techniques and our experience in domestic and international carbon capture and sequestration projects, we analyzed the inherent difficulties and our experiences in geophysical monitoring techniques, especially, with respect to 4D seismic acquisition, processing, and interpretation.

  11. 2.5 MHz Line-Width High-energy, 2 Micrometer Coherent Wind Lidar Transmitter

    NASA Technical Reports Server (NTRS)

    Petros, Mulugeta; Yu, Jirong; Trieu, Bo; Bai, Yingxin; Petzar, Paul; Singh, Upendra N.; Reithmaier, Karl

    2007-01-01

    2 micron solid-state lasers are the primary choice for coherent Doppler wind detection. As wind lidars, they are used for wake vortex and clear air turbulence detection providing air transport safety. In addition, 2 micron lasers are one of the candidates for CO2 detection lidars. The rich CO2 absorption line around 2 micron, combined with the long upper state life of time, has made Ho based 2 micron lasers a viable candidate for CO2 sensing DIAL instrument. The design and fabrication of a compact coherent laser radar transmitter for Troposphere wind sensing is under way. This system is hardened for ground as well as airborne applications. As a transmitter for a coherent wind lidar, this laser has stringent spectral line width and beam quality requirements. Although the absolute wavelength does not have to be fixed for wind detection, to maximize return signal, the output wavelength should avoid atmospheric CO2 and H2O absorption lines. The base line laser material is Ho:Tm:LuLF which is an isomorph of Ho:Tm:YLF. LuLF produces 20% more output power than Ho:Tm:YLF. In these materials the Tm absorption cross-section, the Ho emission cross-section, the Tm to Ho energy transfer parameters and the Ho (sup 5) I (sub 7) radiative life time are all identical. However, the improved performance of the LuLF is attributed to the lower thermal population in the (sup 5) I (sub 8) manifold. It also provides higher normal mode to Q-switch conversion than YLF at high pump energy indicating a lower up-conversion. The laser architecture is composed of a seed laser, a ring oscillator, and a double pass amplifier. The seed laser is a single longitudinal mode with a line width of 13 KHz. The 100mJ class oscillator is stretched to 3 meters to accommodate the line-width requirement without compromising the range resolution of the instrument. The amplifier is double passed to produce greater than 300mJ energy.

  12. Silvering substrates after CO2 snow cleaning

    NASA Astrophysics Data System (ADS)

    Zito, Richard R.

    2005-09-01

    There have been some questions in the astronomical community concerning the quality of silver coatings deposited on substrates that have been cleaned with carbon dioxide snow. These questions center around the possible existence of carbonate ions left behind on the substrate by CO2. Such carbonate ions could react with deposited silver to produce insoluble silver carbonate, thereby reducing film adhesion and reflectivity. Carbonate ions could be produced from CO2 via the following mechanism. First, during CO2 snow cleaning, a small amount of moisture can condense on a surface. This is especially true if the jet of CO2 is allowed to dwell on one spot. CO2 gas can dissolve in this moisture, producing carbonic acid, which can undergo two acid dissociations to form carbonate ions. In reality, it is highly unlikely that charged carbonate ions will remain stable on a substrate for very long. As condensed water evaporates, Le Chatelier's principle will shift the equilibrium of the chain of reactions that produced carbonate back to CO2 gas. Furthermore, the hydration of CO2 reaction of CO2 with H20) is an extremely slow process, and the total dehydrogenation of carbonic acid is not favored. Living tissues that must carry out the equilibration of carbonic acid and CO2 use the enzyme carbonic anhydrase to speed up the reaction by a factor of one million. But no such enzymatic action is present on a clean mirror substrate. In short, the worst case analysis presented below shows that the ratio of silver atoms to carbonate radicals must be at least 500 million to one. The results of chemical tests presented here support this view. Furthermore, film lift-off tests, also presented in this report, show that silver film adhesion to fused silica substrates is actually enhanced by CO2 snow cleaning.

  13. The ins and outs of CO2

    PubMed Central

    Raven, John A.; Beardall, John

    2016-01-01

    It is difficult to distinguish influx and efflux of inorganic C in photosynthesizing tissues; this article examines what is known and where there are gaps in knowledge. Irreversible decarboxylases produce CO2, and CO2 is the substrate/product of enzymes that act as carboxylases and decarboxylases. Some irreversible carboxylases use CO2; others use HCO3 –. The relative role of permeation through the lipid bilayer versus movement through CO2-selective membrane proteins in the downhill, non-energized, movement of CO2 is not clear. Passive permeation explains most CO2 entry, including terrestrial and aquatic organisms with C3 physiology and biochemistry, terrestrial C4 plants and all crassulacean acid metabolism (CAM) plants, as well as being part of some mechanisms of HCO3 – use in CO2 concentrating mechanism (CCM) function, although further work is needed to test the mechanism in some cases. However, there is some evidence of active CO2 influx at the plasmalemma of algae. HCO3 – active influx at the plasmalemma underlies all cyanobacterial and some algal CCMs. HCO3 – can also enter some algal chloroplasts, probably as part of a CCM. The high intracellular CO2 and HCO3 – pools consequent upon CCMs result in leakage involving CO2, and occasionally HCO3 –. Leakage from cyanobacterial and microalgal CCMs involves up to half, but sometimes more, of the gross inorganic C entering in the CCM; leakage from terrestrial C4 plants is lower in most environments. Little is known of leakage from other organisms with CCMs, though given the leakage better-examined organisms, leakage occurs and increases the energetic cost of net carbon assimilation. PMID:26466660

  14. The ins and outs of CO2.

    PubMed

    Raven, John A; Beardall, John

    2016-01-01

    It is difficult to distinguish influx and efflux of inorganic C in photosynthesizing tissues; this article examines what is known and where there are gaps in knowledge. Irreversible decarboxylases produce CO2, and CO2 is the substrate/product of enzymes that act as carboxylases and decarboxylases. Some irreversible carboxylases use CO2; others use HCO3(-). The relative role of permeation through the lipid bilayer versus movement through CO2-selective membrane proteins in the downhill, non-energized, movement of CO2 is not clear. Passive permeation explains most CO2 entry, including terrestrial and aquatic organisms with C3 physiology and biochemistry, terrestrial C4 plants and all crassulacean acid metabolism (CAM) plants, as well as being part of some mechanisms of HCO3(-) use in CO2 concentrating mechanism (CCM) function, although further work is needed to test the mechanism in some cases. However, there is some evidence of active CO2 influx at the plasmalemma of algae. HCO3(-) active influx at the plasmalemma underlies all cyanobacterial and some algal CCMs. HCO3(-) can also enter some algal chloroplasts, probably as part of a CCM. The high intracellular CO2 and HCO3(-) pools consequent upon CCMs result in leakage involving CO2, and occasionally HCO3(-). Leakage from cyanobacterial and microalgal CCMs involves up to half, but sometimes more, of the gross inorganic C entering in the CCM; leakage from terrestrial C4 plants is lower in most environments. Little is known of leakage from other organisms with CCMs, though given the leakage better-examined organisms, leakage occurs and increases the energetic cost of net carbon assimilation. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  15. Dynamics of CO2 fluxes and concentrations during a shallow subsurface CO2 release

    SciTech Connect

    Lewicki, J.L.; Hilley, G.E.; Dobeck, L.; Spangler, L.

    2009-09-01

    A field facility located in Bozeman, Montana provides the opportunity to test methods to detect, locate, and quantify potential CO2 leakage from geologic storage sites. From 9 July to 7 August 2008, 0.3 t CO2 d{sup -1} were injected from a 100-m long, {approx}2.5 m deep horizontal well. Repeated measurements of soil CO2 fluxes on a grid characterized the spatio-temporal evolution of the surface leakage signal and quantified the surface leakage rate. Infrared CO2 concentration sensors installed in the soil at 30 cm depth at 0 to 10 m from the well and at 4 cm above the ground at 0 and 5 m from the well recorded surface breakthrough of CO2 leakage and migration of CO2 leakage through the soil. Temporal variations in CO2 concentrations were correlated with atmospheric and soil temperature, wind speed, atmospheric pressure, rainfall, and CO2 injection rate.

  16. A usage of CO2 hydrate: convenient method to increase CO2 concentration in culturing algae.

    PubMed

    Nakano, Sho; Chang, Kwang-Hyeon; Shijima, Atsushi; Miyamoto, Hiroyuki; Sato, Yukio; Noto, Yuji; Ha, Jin-Yong; Sakamoto, Masaki

    2014-11-01

    The addition of CO2 to algal culture systems can increase algal biomass effectively. Generally, gas bubbling is used to increase CO2 levels in culture systems; however, it is difficult to quantitatively operate to control the concentration using this method. In this study, we tested the usability of CO2 hydrate for phytoplankton culture. Specifically, green algae Pseudokirchneriella subcapitata were cultured in COMBO medium that contained dissolved CO2 hydrate, after which its effects were evaluated. The experiment was conducted according to a general bioassay procedure (OECD TG201). CO2 promoted algae growth effectively (about 2-fold relative to the control), and the decrease in pH due to dissolution of the CO2 in water recovered soon because of photosynthesis. Since the CO2 hydrate method can control a CO2 concentration easily and quantitatively, it is expected to be useful in future applications.

  17. Differential Absorption Lidar (DIAL) Measurements of Landfill Methane Emissions

    NASA Astrophysics Data System (ADS)

    Innocenti, Fabrizio; Robinson, Rod; Gardiner, Tom; Finlayson, Andrew; Connor, Andy

    2017-04-01

    DIFFERENTIAL ABSORPTION LIDAR (DIAL) MEASURMENTS OF LANDFILL METHANE EMISSIONS F. INNOCENTI *, R.A. ROBINSON *, T.D. GARDINER, A. FINLAYSON *, A. CONNOR* * National Physical Laboratory (NPL), Hampton Road, Teddington, Middlesex, TW11 0LW, United Kingdom Methane is one of the most important gaseous hydrocarbon species for both industrial and environmental reasons. Understanding and quantifying methane emissions to atmosphere is an important element of climate change research. Range-resolved infrared Differential Absorption Lidar (DIAL) measurements provide the means to map and quantify a wide range of different methane sources. DIAL is a powerful technique that can be used to track and quantify plumes emitted from area emission sources such as landfill sites, waste water treatment plants and petrochemical plants. By using lidar (light detection and ranging), the DIAL technique is able to make remote range-resolved single-ended measurements of the actual distribution of target gases in the atmosphere, with no disruption to normal site operational activities. DIAL provides 3D mapping of emission concentrations and quantification of emission rates for a wide range of target gases such as methane. The NPL DIAL laser source is operated alternately at two similar wavelengths. One of these, termed the "on-resonant wavelength", is chosen to be at a wavelength which is absorbed by the target species. The other, the "off-resonant wavelength", is chosen to be at a nearby wavelength which is not absorbed significantly by the target species. The two wavelengths are chosen to be close, so that the atmospheric scattering properties are the same for both wavelengths. They are also chosen so that any differential absorption due to other atmospheric species are minimised. Any measured difference in the returned signals is therefore due to absorption by the target gas. In the typical DIAL measurement configuration the mobile DIAL facility is positioned downwind of the area being

  18. CO2 deserts: implications of existing CO2 supply limitations for carbon management.

    PubMed

    Middleton, Richard S; Clarens, Andres F; Liu, Xiaowei; Bielicki, Jeffrey M; Levine, Jonathan S

    2014-10-07

    Efforts to mitigate the impacts of climate change will require deep reductions in anthropogenic CO2 emissions on the scale of gigatonnes per year. CO2 capture and utilization and/or storage technologies are a class of approaches that can substantially reduce CO2 emissions. Even though examples of this approach, such as CO2-enhanced oil recovery, are already being practiced on a scale >0.05 Gt/year, little attention has been focused on the supply of CO2 for these projects. Here, facility-scale data newly collected by the U.S. Environmental Protection Agency was processed to produce the first comprehensive map of CO2 sources from industrial sectors currently supplying CO2 in the United States. Collectively these sources produce 0.16 Gt/year, but the data reveal the presence of large areas without access to CO2 at an industrially relevant scale (>25 kt/year). Even though some facilities with the capability to capture CO2 are not doing so and in some regions pipeline networks are being built to link CO2 sources and sinks, much of the country exists in "CO2 deserts". A life cycle analysis of the sources reveals that the predominant source of CO2, dedicated wells, has the largest carbon footprint further confounding prospects for rational carbon management strategies.

  19. CO2 Accounting and Risk Analysis for CO2 Sequestration at Enhanced Oil Recovery Sites.

    PubMed

    Dai, Zhenxue; Viswanathan, Hari; Middleton, Richard; Pan, Feng; Ampomah, William; Yang, Changbing; Jia, Wei; Xiao, Ting; Lee, Si-Yong; McPherson, Brian; Balch, Robert; Grigg, Reid; White, Mark

    2016-07-19

    Using CO2 in enhanced oil recovery (CO2-EOR) is a promising technology for emissions management because CO2-EOR can dramatically reduce sequestration costs in the absence of emissions policies that include incentives for carbon capture and storage. This study develops a multiscale statistical framework to perform CO2 accounting and risk analysis in an EOR environment at the Farnsworth Unit (FWU), Texas. A set of geostatistical-based Monte Carlo simulations of CO2-oil/gas-water flow and transport in the Morrow formation are conducted for global sensitivity and statistical analysis of the major risk metrics: CO2/water injection/production rates, cumulative net CO2 storage, cumulative oil/gas productions, and CO2 breakthrough time. The median and confidence intervals are estimated for quantifying uncertainty ranges of the risk metrics. A response-surface-based economic model has been derived to calculate the CO2-EOR profitability for the FWU site with a current oil price, which suggests that approximately 31% of the 1000 realizations can be profitable. If government carbon-tax credits are available, or the oil price goes up or CO2 capture and operating expenses reduce, more realizations would be profitable. The results from this study provide valuable insights for understanding CO2 storage potential and the corresponding environmental and economic risks of commercial-scale CO2-sequestration in depleted reservoirs.

  20. Effects of CO2 leakage on soil bacterial communities from simulated CO2-EOR areas.

    PubMed

    Chen, Fu; Yang, Yongjun; Ma, Yanjun; Hou, Huping; Zhang, Shaoliang; Ma, Jing

    2016-05-18

    CO2-EOR (enhanced oil recovery) has been proposed as a viable option for flooding oil and reducing anthropogenic CO2 contribution to the atmospheric pool. However, the potential risk of CO2 leakage from the process poses a threat to the ecological system. High-throughput sequencing was used to investigate the effects of CO2 emission on the composition and structure of soil bacterial communities. The diversity of bacterial communities notably decreased with increasing CO2 flux. The composition of bacterial communities varied along the CO2 flux, with increasing CO2 flux accompanied by increases in the relative abundance of Bacteroidetes and Firmicutes phyla, but decreases in the relative abundance of Acidobacteria and Chloroflexi phyla. Within the Firmicutes phylum, the genus Lactobacillus increased sharply when the CO2 flux was at its highest point. Alpha and beta diversity analysis revealed that differences in bacterial communities were best explained by CO2 flux. The redundancy analysis (RDA) revealed that differences in bacterial communities were best explained by soil pH values which related to CO2 flux. These results could be useful for evaluating the risk of potential CO2 leakages on the ecosystems associated with CO2-EOR processes.

  1. Glacial CO2 Cycles: A Composite Scenario

    NASA Astrophysics Data System (ADS)

    Broecker, W. S.

    2015-12-01

    There are three main contributors to the glacial drawdown of atmospheric CO2 content: starvation of the supply of carbon to the ocean-atmosphere reservoir, excess CO2 storage in the deep sea, and surface-ocean cooling. In this talk, I explore a scenario in which all three play significant roles. Key to this scenario is the assumption that deep ocean storage is related to the extent of nutrient stratification of the deep Atlantic. The stronger this stratification, the larger the storage of respiration CO2. Further, it is my contention that the link between Milankovitch insolation cycles and climate is reorganizations of the ocean's thermohaline circulation leading to changes in the deep ocean's CO2 storage. If this is the case, the deep Atlantic d13C record kept in benthic foraminifera shells tells us that deep ocean CO2 storage follows Northern Hemisphere summer insolation cycles and thus lacks the downward ramp so prominent in the records of sea level, benthic 18O and CO2. Rather, the ramp is created by the damping of planetary CO2 emissions during glacial time intervals. As it is premature to present a specific scenario, I provide an example as to how these three contributors might be combined. As their magnitudes and shapes remain largely unconstrained, the intent of this exercise is to provoke creative thinking.

  2. CO2 mitigation via accelerated limestone weathering

    USGS Publications Warehouse

    Rau, Greg H.; Knauss, Kevin G.; Langer, William H.; Caldeira,

    2004-01-01

    We evaluate accelerated weathering of limestone (AWL: CO2 + CaCO3 + H2O=> Ca2+ + 2HCO3-) as a low-tech, inexpensive, high-capacity, environmentally-friendly CO2 capture and sequestration technology. With access to seawater and limestone being essential to this approach, significant limestone resources are close to most CO2-emitting power plants along the coastal US. Waste fines, representing more than 20% of current US crushed limestone production (>109 tonnes/yr), could be used as an inexpensive source of AWL carbonate. Under such circumstances CO2 mitigation cost could be as low as $3-$4/tonne. More broadly, 10-20% of US point-source CO2 emissions could be treated at $20-$30/tonne CO2. AWL end-solution disposal in the ocean would significantly reduce effects on ocean pH and carbonate chemistry relative to those caused by direct atmospheric or ocean CO2 disposal. Indeed, the increase in ocean Ca2+ and bicarbonate offered by AWL should enhance growth of corals and other calcifying marine organisms.

  3. Engineered yeast for enhanced CO2 mineralization†

    PubMed Central

    Barbero, Roberto; Carnelli, Lino; Simon, Anna; Kao, Albert; Monforte, Alessandra d’Arminio; Riccò, Moreno; Bianchi, Daniele; Belcher, Angela

    2014-01-01

    In this work, a biologically catalyzed CO2 mineralization process for the capture of CO2 from point sources was designed, constructed at a laboratory scale, and, using standard chemical process scale-up protocols, was modeled and evaluated at an industrial scale. A yeast display system in Saccharomyces cerevisae was used to screen several carbonic anhydrase isoforms and mineralization peptides for their impact on CO2 hydration, CaCO3 mineralization, and particle settling rate. Enhanced rates for each of these steps in the CaCO3 mineralization process were confirmed using quantitative techniques in lab-scale measurements. The effect of these enhanced rates on the CO2 capture cost in an industrial scale CO2 mineralization process using coal fly ash as the CaO source was evaluated. The model predicts a process using bCA2- yeast and fly ash is ~10% more cost effective per ton of CO2 captured than a process with no biological molecules, a savings not realized by wild-type yeast and high-temperature stable recombinant CA2 alone or in combination. The levelized cost of electricity for a power plant using this process was calculated and scenarios in which this process compares favorably to CO2 capture by MEA absorption process are presented. PMID:25289021

  4. Elevated CO2 and Soil Nitrogen Cycling

    NASA Astrophysics Data System (ADS)

    Hofmockel, K.; Schlesinger, W.

    2002-12-01

    Although forests can be large terrestrial carbon sinks, soil fertility can limit carbon sequestration in response to increased atmospheric CO2. During five years of CO2 fertilization (ambient + 200ppm) at the Duke Free-Air CO2 Enrichment (FACE) site, net primary production increased significantly by an average of 25% in treatment plots. Total nitrogen in the foliar canopy increased by 16%, requiring an additional 1.3 g N m-2yr-1 to be taken up from soils under elevated CO2. Mechanisms supporting increased nitrogen acquisition have not been identified. Here we report on biological N-fixation rates, using the acetylene reduction assay, in litter and mineral soil during three years of the CO2 enrichment experiment. Lack of a significant CO2 treatment effect on acetylene reduction indicates that carbon is not directly limiting biological N fixation. Nutrient addition experiments using a complete block design with glucose, Fe, Mo and P indicate biological N fixation is co-limited by molybdenum and carbon. These results suggest even if elevated atmospheric CO2 enhances below-ground carbon availability via root exudation, biological nitrogen fixation may not be stimulated due to micronutrient limitations. Assessment of future carbon sequestration by forest stands must consider limitations imposed by site fertility, including micronutrients.

  5. Engineered yeast for enhanced CO2 mineralization.

    PubMed

    Barbero, Roberto; Carnelli, Lino; Simon, Anna; Kao, Albert; Monforte, Alessandra d'Arminio; Riccò, Moreno; Bianchi, Daniele; Belcher, Angela

    2013-02-01

    In this work, a biologically catalyzed CO2 mineralization process for the capture of CO2 from point sources was designed, constructed at a laboratory scale, and, using standard chemical process scale-up protocols, was modeled and evaluated at an industrial scale. A yeast display system in Saccharomyces cerevisae was used to screen several carbonic anhydrase isoforms and mineralization peptides for their impact on CO2 hydration, CaCO3 mineralization, and particle settling rate. Enhanced rates for each of these steps in the CaCO3 mineralization process were confirmed using quantitative techniques in lab-scale measurements. The effect of these enhanced rates on the CO2 capture cost in an industrial scale CO2 mineralization process using coal fly ash as the CaO source was evaluated. The model predicts a process using bCA2- yeast and fly ash is ~10% more cost effective per ton of CO2 captured than a process with no biological molecules, a savings not realized by wild-type yeast and high-temperature stable recombinant CA2 alone or in combination. The levelized cost of electricity for a power plant using this process was calculated and scenarios in which this process compares favorably to CO2 capture by MEA absorption process are presented.

  6. Airborne water vapor DIAL research: System development and field measurements

    NASA Technical Reports Server (NTRS)

    Higdon, Noah S.; Browell, Edward V.; Ponsardin, Patrick; Chyba, Thomas H.; Grossmann, Benoist E.; Butler, Carolyn F.; Fenn, Marta A.; Mayor, Shane D.; Ismail, Syed; Grant, William B.

    1992-01-01

    This paper describes the airborne differential absorption lidar (DIAL) system developed at the NASA Langley Research Center for remote measurement of water vapor (H2O) and aerosols in the lower atmosphere. The airborne H2O DIAL system was flight tested aboard the NASA Wallops Flight Facility (WFF) Electra aircraft in three separate field deployments between 1989 and 1991. Atmospheric measurements were made under a variety of atmospheric conditions during the flight tests, and several modifications were implemented during this development period to improve system operation. A brief description of the system and major modifications will be presented, and the most significant atmospheric observations will be described.

  7. Airborne water vapor DIAL research: System development and field measurements

    NASA Technical Reports Server (NTRS)

    Higdon, Noah S.; Browell, Edward V.; Ponsardin, Patrick; Chyba, Thomas H.; Grossmann, Benoist E.; Butler, Carolyn F.; Fenn, Marta A.; Mayor, Shane D.; Ismail, Syed; Grant, William B.

    1992-01-01

    This paper describes the airborne differential absorption lidar (DIAL) system developed at the NASA Langley Research Center for remote measurement of water vapor (H2O) and aerosols in the lower atmosphere. The airborne H2O DIAL system was flight tested aboard the NASA Wallops Flight Facility (WFF) Electra aircraft in three separate field deployments between 1989 and 1991. Atmospheric measurements were made under a variety of atmospheric conditions during the flight tests, and several modifications were implemented during this development period to improve system operation. A brief description of the system and major modifications will be presented, and the most significant atmospheric observations will be described.

  8. CALIOPE airborne CO{sub 2} DIAL (CACDI) system design

    SciTech Connect

    Mietz, D.; Archuleta, B.; Archuleta, J.

    1997-09-01

    Los Alamos National Laboratory is currently developing an airborne CO{sub 2} Differential Absorption Lidar (DIAL) system based on second generation technology demonstrated last summer at NTS. The CALIOPE Airborne CO{sub 2} DIAL (CACDI) system requirements have been compiled based on the mission objectives and SONDIAL model trade studies. Subsystem designs have been developed based on flow down from these system requirements, as well as experience gained from second generation ground tests and N-ABLE (Non-proliferation AirBorne Lidar Experiments) airborne experiments. This paper presents the CACDI mission objectives, system requirements, the current subsystem design, and provides an overview of the airborne experimental plan.

  9. Geological factors affecting CO2 plume distribution

    USGS Publications Warehouse

    Frailey, S.M.; Leetaru, H.

    2009-01-01

    Understanding the lateral extent of a CO2 plume has important implications with regards to buying/leasing pore volume rights, defining the area of review for an injection permit, determining the extent of an MMV plan, and managing basin-scale sequestration from multiple injection sites. The vertical and lateral distribution of CO2 has implications with regards to estimating CO2 storage volume at a specific site and the pore pressure below the caprock. Geologic and flow characteristics such as effective permeability and porosity, capillary pressure, lateral and vertical permeability anisotropy, geologic structure, and thickness all influence and affect the plume distribution to varying degrees. Depending on the variations in these parameters one may dominate the shape and size of the plume. Additionally, these parameters do not necessarily act independently. A comparison of viscous and gravity forces will determine the degree of vertical and lateral flow. However, this is dependent on formation thickness. For example in a thick zone with injection near the base, the CO2 moves radially from the well but will slow at greater radii and vertical movement will dominate. Generally the CO2 plume will not appreciably move laterally until the caprock or a relatively low permeability interval is contacted by the CO2. Conversely, in a relatively thin zone with the injection interval over nearly the entire zone, near the wellbore the CO2 will be distributed over the entire vertical component and will move laterally much further with minimal vertical movement. Assuming no geologic structure, injecting into a thin zone or into a thick zone immediately under a caprock will result in a larger plume size. With a geologic structure such as an anticline, CO2 plume size may be restricted and injection immediately below the caprock may have less lateral plume growth because the structure will induce downward vertical movement of the CO2 until the outer edge of the plume reaches a spill

  10. Regenerable Sorbent for CO2 Removal

    NASA Technical Reports Server (NTRS)

    Alptekin, Gokhan; Jayaraman, Ambal

    2013-01-01

    A durable, high-capacity regenerable sorbent can remove CO2 from the breathing loop under a Martian atmosphere. The system design allows near-ambient temperature operation, needs only a small temperature swing, and sorbent regeneration takes place at or above 8 torr, eliminating the potential for Martian atmosphere to leak into the regeneration bed and into the breathing loop. The physical adsorbent can be used in a metabolic, heat-driven TSA system to remove CO2 from the breathing loop of the astronaut and reject it to the Martian atmosphere. Two (or more) alternating sorbent beds continuously scrub and reject CO2 from the spacesuit ventilation loop. The sorbent beds are cycled, alternately absorbing CO2 from the vent loop and rejecting the adsorbed material into the environment at a high CO2 partial pressure (above 8 torr). The system does not need to run the adsorber at cryogenic temperatures, and uses a much smaller temperature swing. The sorbent removes CO2 via a weak chemical interaction. The interaction is strong enough to enable CO2 adsorption even at 3 to 7.6 torr. However, because the interaction between the surface adsorption sites and the CO2 is relatively weak, the heat input needed to regenerate the sorbent is much lower than that for chemical absorbents. The sorbent developed in this project could potentially find use in a large commercial market in the removal of CO2 emissions from coal-fired power plants, if regulations are put in place to curb carbon emissions from power plants.

  11. Can increasing CO2 cool Antarctica?

    NASA Astrophysics Data System (ADS)

    Schmithuesen, Holger; Notholt, Justus; König-Langlo, Gert; Lemke, Peter

    2014-05-01

    CO2 is the strongest anthropogenic forcing agent for climate change since pre-industrial times. Like other greenhouse gases, CO2 absorbs terrestrial surface radiation and causes emission from the atmosphere to space. As the surface is generally warmer than the atmosphere, the total long-wave emission to space is commonly less than the surface emission. However, this does not hold true for the high elevated areas of central Antarctica. Our investigations show, that for the high elevated areas of Antarctica the greenhouse effect (GHE) of CO2 is commonly around zero or even negative. This is based on the quantification of GHE as the difference between long-wave surface emission and top of atmosphere emission. We demonstrate this behaviour with the help of three models: a simple two-layer model, line-by-line calculations, and an ECMWF experiment. Additionally, in this region an increase in CO2 concentration leads to an instantaneous increased long-wave energy loss to space, which is a cooling effect on the earth-atmosphere system. However, short-wave warming by the weak absorption of solar radiation by CO2 are not taken into account here. The reason for this counter-intuitive behaviour is the fact that in the interior of Antarctica the surface is often colder than the stratosphere above. Radiation from the surface in the atmospheric window emitted to space is then relatively lower compared to radiation in the main CO2 band around 15 microns, which originates mostly from the stratosphere. Increasing CO2 concentration leads to increasing emission from the atmosphere to space, while blocking additional portions of surface emission. If the surface is colder than the stratosphere, this leads to additional long-wave energy loss to space for increasing CO2. Our findings for central Antarctica are in strong contrast to the generally known effect that increasing CO2 has on the long-wave emission to space, and hence on the Antarctic climate.

  12. Laser Sounder Approach for Measuring Atmospheric CO2 Concentrations for the ASCENDS Mission

    NASA Astrophysics Data System (ADS)

    Abshire, J. B.; Riris, H.; Allan, G. R.; Sun, X.; Wilson, E.; Stephen, M. A.; Weaver, C.

    2008-12-01

    Accurate measurements of tropospheric CO2 abundances with global-coverage and monthly temporal resolution are needed to quantify processes that regulate CO2 exchange with the land and oceans. To meet this need, the 2007 Decadal Survey for Earth Science by the US National Research Council recommended a laser-based CO2 measuring mission called ASCENDS. In July 2008 NASA convened a science definition workshop for ASCENDS, which helped better define the mission and measurement requirements. We have been developing a technique for the remote measurement of tropospheric CO2 concentrations from aircraft and spacecraft. Our immediate goal is to develop and demonstrate the lidar technique and technology that will permit measurements of the CO2 column abundance over horizontal paths and from aircraft at the few-ppmv level. Our longer-term goal is to demonstrate the capabilities of the technique and instrument design needed for an ASCENDS-type mission. Our approach uses the 1570-nm band and a dual channel laser absorption spectrometer (ie DIAL used in altimeter mode). It uses several tunable fiber laser transmitters allowing simultaneous measurement of the absorption from a CO2 absorption line in the 1570 nm band, O2 extinction in the oxygen A-band, and surface height and aerosol backscatter in the same path. It directs the narrow co-aligned laser beams toward nadir, and measures the energy of the laser echoes reflected from land and water surfaces. The lasers are tuned on and off the sides of CO2 line and an O2 line (near 765 nm) at kHz rates. The receiver uses a telescope and photon counting detectors, and measures the background light and energies of the laser echoes from the surface along with scattering from any aerosols in the path. The gas extinction and column densities for the CO2 and O2 gases are estimated from the ratio of the on and off line signals via the DIAL technique. We use pulsed laser signals and time gating to isolate the laser echo signals from the

  13. Atmospheric CO2 Removal by Enhancing Weathering

    NASA Astrophysics Data System (ADS)

    Koster van Groos, A. F.; Schuiling, R. D.

    2014-12-01

    The increase of the CO2 content in the atmosphere by the release of anthropogenic CO2 may be addressed by the enhancement of weathering at the surface of the earth. The average emission of mantle-derived CO2 through volcanism is ~0.3 Gt/year (109 ton/year). Considering the ~3.000 Gt of CO2 present in the atmosphere, the residence time of CO2 in the earth's atmosphere is ~10,000 years. Because the vast proportion of carbon in biomass is recycled through the atmosphere, CO2 is continuously removed by a series of weathering reactions of silicate minerals and stored in calcium and magnesium carbonates. The addition of anthropogenic CO2 from fossil fuel and cement production, which currently exceeds 35 Gt/year and dwarfs the natural production 100-fold, cannot be compensated by current rates of weathering, and atmospheric CO2 levels are rising rapidly. To address this increase in CO2 levels, weathering rates would have to be accelerated on a commensurate scale. Olivine ((Mg,Fe)2SiO4) is the most reactive silicate mineral in the weathering process. This mineral is the major constituent in relatively common ultramafic rocks such as dunites (olivine content > 90%). To consume the current total annual anthropogenic release of CO2, using a simplified weathering reaction (Mg2SiO4 + 4CO2 + 4H2O --> 2 Mg2+ + 4HCO3- + H4SiO4) would require ~30 Gt/year or ~8-9 km3/year of dunite. This is a large volume; it is about double the total amount of ore and gravel currently mined (~ 17 Gt/year). To mine and crush these rocks to <100 μm costs ~ 8/ton. The transport and distribution over the earth's surface involves additional costs, that may reach 2-5/ton. Thus, the cost of remediation for the release of anthropogenic CO2 is 300-400 billion/year. This compares to a 2014 global GDP of ~80 trillion. Because weathering reactions require the presence of water and proceed more rapidly at higher temperatures, the preferred environments to enhance weathering are the wet tropics. From a socio

  14. The Oceanic Sink for Anthropogenic CO2

    SciTech Connect

    Sabine, Chris; Feely, R. A.; Gruber, N.; Key, Robert; Lee, K.; Bullister, J.L.; Wanninkhof, R.; Wong, C. S.; Wallace, D.W.R.; Tilbrook, B.; Millero, F. J.; Peng, T.-H.; Kozyr, Alexander; Ono, Tsueno

    2004-01-01

    Using inorganic carbon measurements from an international survey effort in the 1990s and a tracer-based separation technique, we estimate a global oceanic anthropogenic carbon dioxide (CO2) sink for the period from 1800 to 1994 of 118 19 petagrams of carbon. The oceanic sink accounts for ~48% of the total fossil-fuel and cement-manufacturing emissions, implying that the terrestrial biosphere was a net source of CO2 to the atmosphere of about 39 28 petagrams of carbon for this period. The current fraction of total anthropogenic CO2 emissions stored in the ocean appears to be about one-third of the long-term potential.

  15. Studies on CO 2 laser marking

    NASA Astrophysics Data System (ADS)

    Ueda, Masahiro; Saitoh, Yoshikazu; Hachisuka, Hideki; Ishigaki, Hiroyuki; Gokoh, Yukihiro; Mantani, Hiroshi

    The nature of CO 2 laser marking was studied with a view to putting these lasers to practical use in the semiconductor industry. The marking is found to be due to surface spattering rather than burning, which is the main factor in YAG laser marking. The visibility greatly increases by the application of a surface treatment such as marker ink, varnish or poster color. The CO 2 laser may therefore be used in place of the YAG laser, now widely used for marking, with some merits: CO 2 laser marking is cheaper and faster, and in addition there is no danger of injury from irradiating laser light.

  16. The oceanic sink for anthropogenic CO2.

    PubMed

    Sabine, Christopher L; Feely, Richard A; Gruber, Nicolas; Key, Robert M; Lee, Kitack; Bullister, John L; Wanninkhof, Rik; Wong, C S; Wallace, Douglas W R; Tilbrook, Bronte; Millero, Frank J; Peng, Tsung-Hung; Kozyr, Alexander; Ono, Tsueno; Rios, Aida F

    2004-07-16

    Using inorganic carbon measurements from an international survey effort in the 1990s and a tracer-based separation technique, we estimate a global oceanic anthropogenic carbon dioxide (CO2) sink for the period from 1800 to 1994 of 118 +/- 19 petagrams of carbon. The oceanic sink accounts for approximately 48% of the total fossil-fuel and cement-manufacturing emissions, implying that the terrestrial biosphere was a net source of CO2 to the atmosphere of about 39 +/- 28 petagrams of carbon for this period. The current fraction of total anthropogenic CO2 emissions stored in the ocean appears to be about one-third of the long-term potential.

  17. A radiatively pumped CW CO2 laser

    NASA Technical Reports Server (NTRS)

    Insuik, R. J.; Christiansen, W. H.

    1984-01-01

    A proof of principle experiment to demonstrate the physics of a radiatively pumped laser has been carried out. For the first time, a blackbody cavity has optically pumped a CW CO2 laser. Results are presented from a series of experiments using mixtures of CO2, He, and Ar in which maximum output power was obtained with a 20 percent CO2-15 percent He-65 percent Ar mixture. The dependence of the output power on the blackbody temperature and the cooling gas flow rate is also discussed. By appropriately varying these parameters, continuous output powers of 8-10 mW have been achieved.

  18. Natural Analog for Geologic Storage of CO2: CO2 accumulation in China

    NASA Astrophysics Data System (ADS)

    Liu, L.; Xu, T.; Liu, N.; Zhou, B.

    2012-12-01

    Natural accumulations of CO2 are potential analogues of CO2 geological storage that can provide useful information on the behaviour of supercritical CO2 in reservoirs. Natural CO2 accumulations are common across Northeast China, and, although they occur in a wide variety of geological settings, their distribution is principally controlled by the Mesozoic-Cenozoic rift basins and associated Quaternary volcanism. High CO2 concentrations (>60 CO2%) in natural gas reservoirs are usually related to volcanism and magmatism, and possesses mantle-genetic origin. CO2 reservoirs consist of sandstone, volcanic rocks and carbonate rocks with the buried depth from 2000-3000 m. Dawsonite is recognized in almost all of the CO2-bearing basin, which has been proved to share the same carbon source with CO2 in the reservoirs in Songliao basin, Hailaer basin and Donghai basin. Petrographic data show that dawsonite is abundant in feldspar- rich sandstone, volcanic rock fragment-rich sandstones and tuff. In some cases, high percentage of dawsonite cement constitutes a diagenetic seal, which occurs in the reservoir-mudstone caprock and prevents upward leakage of CO2. Besides dawsonite, mantle-genetic CO2 flux leads to the formation of calcite, ankerite and siderite. The statistics of porosity and permeability measured from the dawsonite-bearing sandstone and dawsonite-absent sandstone with the almost same burial depth in Songliao basin show that the mantle-genetic CO2 flux result in lower reservoir quality, suggesting that mineral trapping for CO2 is significant. Chemical analyses of formation water in Songliao basin and Hailaer basin indicate that the concentrations of TDS, HCO3-,CO32-, Mg2+,Ca2+ and Na+ + K+ in dawsonite-bearing sandstone are higher than that in dawsonite-absent sandstone. Distribution of CO2 and dawsonite is constrainted by the regional caprocks in the Songliao basin. The charging time of the mantle-genetic CO2 in China dates from 50 to 25 Ma.

  19. CO2-Leaking Well - Analytical Modeling

    NASA Astrophysics Data System (ADS)

    Wertz, F.; Audigane, P.; Bouc, O.

    2009-04-01

    The long-term integrity of CO2 storage in geological system relies highly on local trapping mechanisms but also on the absence/control of any kind of outlets. Indeed numerous pathways (faults, wells, rock heterogeneities…) exist that can lead stored gas back to the surface. Thus, such leakage risks must be assessed and quantified if possible. In France, BRGM is inquired for evaluating safety criteria and developing a methodology for qualifying potential geological storage sites. This implies in particular to study the leakage scenario, here through a water-filled well as a worth scenario case. In order to determine the kinds of impacts leaking CO2 can have; knowing the velocity and flow rate of uprising CO2 is a necessity. That is why a better knowledge of CO2 in storage conditions and its behaviour with the environment is required. The following study aims at characterising the CO2 flowing into the well and then rising up in a water column over the vertical dimension. An analytical model was built that describes: - In a first step, the CO2 flow between the reservoir and the inside of the well, depending on quality and thickness of different seals, which determines the flow rate through the well. - In a second step, the CO2 uprising through an open and water filled well, however in steady state, which excludes a priori the characterisation of periodic or chaotic behaviours such as geyser formation. The objective is to give numerous orders of magnitude concerning CO2 thermodynamic properties while rising up: specific enthalpy, density, viscosity, velocity, flow, gas volume fraction and expansion, pressure and temperature gradient. Dissolution is partially taken into account, however without kinetic. The strength of this model is to compute analytically - easily and instantaneously - the 1-dimensional rising velocity of CO2 in a water column as a function of the CO2 density, interfacial tension and initial volume fraction. Characteristic speeds - the ones given by

  20. 40 CFR 98.423 - Calculating CO2 supply.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... = Quarterly CO2 concentration measurement in flow for flow meter u in quarter p (wt. %CO2). Qp,u = Quarterly... (metric tons) through flow meter u. CCO2,p = Quarterly CO2 concentration measurement in flow for flow... delivered by CO2 stream u. CCO2,p,u = Quarterly CO2 concentration measurement of CO2 stream u that...

  1. Translucent CO2 ice on Mars ?

    NASA Astrophysics Data System (ADS)

    Schmidt, Frederic; Andrieu, Francois; Douté, Sylvain; Schmitt, Bernard

    2016-10-01

    The Martian climate is driven by the condensation/sublimation of CO2 representing 95% of the atmosphere. Many active surface features (such dark spot, dark flows), have been potentially linked to CO2 exchange. Understanding the surface/atmosphere interactions is a major issue, for both atmospheric but also surface science. This study aims at estimating the physical properties of the seasonal CO2 ice deposits. Are these deposits granular or compact? What is the thickness of the ice? How much impurities are included within the ice? These questions have been highly debated in the literature, in particular the presence of a translucent slab ice, the link with the H2O cycle. In particular the cold jet geyser model requires translucent CO2 ice. We use radiative transfer models to simulate spectroscopic data from the CRISM instrument and perform an inversion to estimate model's parameters though time. We then discuss the consistency of the results with other datasets.

  2. Photocatalytic Conversion of CO2 on Mars

    NASA Technical Reports Server (NTRS)

    Meier, Annie; Hare, Bryan

    2016-01-01

    Light on Mars shows potential for providing the energy means necessary for enhanced In-Situ Resource Utilization (ISRU). Through photocatalysis, the energy barrier required to convert CO2 is lowered and CH4 production is favorable.

  3. CO2 Sensing and CO2 Regulation of Stomatal Conductance: Advances and Open Questions.

    PubMed

    Engineer, Cawas B; Hashimoto-Sugimoto, Mimi; Negi, Juntaro; Israelsson-Nordström, Maria; Azoulay-Shemer, Tamar; Rappel, Wouter-Jan; Iba, Koh; Schroeder, Julian I

    2016-01-01

    Guard cells form epidermal stomatal gas-exchange valves in plants and regulate the aperture of stomatal pores in response to changes in the carbon dioxide (CO2) concentration ([CO2]) in leaves. Moreover, the development of stomata is repressed by elevated CO2 in diverse plant species. Evidence suggests that plants can sense [CO2] changes via guard cells and via mesophyll tissues in mediating stomatal movements. We review new discoveries and open questions on mechanisms mediating CO2-regulated stomatal movements and CO2 modulation of stomatal development, which together function in the CO2 regulation of stomatal conductance and gas exchange in plants. Research in this area is timely in light of the necessity of selecting and developing crop cultivars that perform better in a shifting climate.

  4. CO2 laser technology for space applications

    NASA Astrophysics Data System (ADS)

    Reiland, W.; Wittig, M.

    1987-01-01

    The paper summarizes the current status of CO2 laser technology development and emphasizes the potential of emerging CO2 hardware components and subsystems for future optical space mission scenarios. Free space optical communications, navigation, lidar applications, and scientific missions are among the space application scenarios considered. It is noted that ESA, NASA, and Intelsat have selected the direct detection GaAlAs system for near-term preoperational applications of medium link distances and data rates.

  5. Study on CO2 global recycling system.

    PubMed

    Takeuchi, M; Sakamoto, Y; Niwa, S

    2001-09-28

    In order to assist in finding ways to mitigate CO2 emission and to slow the depletion of fossil fuels we have established and evaluated a representative system, which consists of three technologies developed in our laboratory. These technologies were in CO2 recovery, hydrogen production and methanol synthesis and in addition we established the necessary supporting systems. Analysis of outline designs of the large scale renewable energy power generation system and this system and energy input for building plant, energy input for running plant has been conducted based on a case using this system for a 1000-MW coal fired power plant, followed by an evaluation of the material balance and energy balance. The results are as follows. Energy efficiency is 34%, the CO2 reduction rate is 41%, the balance ratio of the energy and CO2 of the system is 2.2 and 1.8, respectively, on the assumption that the primary renewable energy is solar thermal power generation, the stationary CO2 emission source is a coal-fired power plant and the generation efficiency of the methanol power plant is 60%. By adopting the system, 3.7 million tons of CO2 can be recovered, approximately 2.7 million tons of methanol can be produced, and 15.4 billion kWh of electricity can be generated per year. Compared to generating all electrical power using only coal, approximately 2.6 million tons of coal per year can be saved and approximately 2.15 million tons of CO2 emission can be reduced. Therefore, it is clearly revealed that this system would be effective to reduce CO2 emissions and to utilize renewable energy.

  6. The Twelve Principles of CO2 CHEMISTRY.

    PubMed

    Poliakoff, Martyn; Leitner, Walter; Streng, Emilia S

    2015-01-01

    This paper introduces a set of 12 Principles, based on the acronym CO2 CHEMISTRY, which are intended to form a set of criteria for assessing the viability of different processes or reactions for using CO2 as a feedstock for making organic chemicals. The principles aim to highlight the synergy of Carbon Dioxide Utilisation (CDU) with the components of green and sustainable chemistry as well as briefly pointing out the connection to the energy sector.

  7. Spatiotemporal variability of lake pCO2 and CO2 fluxes in a hemiboreal catchment

    NASA Astrophysics Data System (ADS)

    Natchimuthu, Sivakiruthika; Sundgren, Ingrid; Gâlfalk, Magnus; Klemedtsson, Leif; Bastviken, David

    2017-01-01

    Globally, lakes are frequently supersaturated with carbon dioxide (CO2) and are major emitters of carbon to the atmosphere. Recent studies have generated awareness of the high variability in pCO2aq (the partial pressure corresponding to the concentration in water) and CO2 fluxes to the atmosphere and the need for better accounting for this variability. However, studies simultaneously accounting for both spatial and temporal variability of pCO2aq and CO2 fluxes in lakes are rare. We measured pCO2aq (by both manual sampling and mini loggers) and CO2 fluxes, covering spatial variability in open water areas of three lakes of different character in a Swedish catchment for 2 years. Spatial pCO2aq variability within lakes was linked to distance from shore, proximity to stream inlets, and deepwater upwelling events. Temporally, pCO2aq variability was linked with variability in dissolved organic carbon, total nitrogen, and dissolved oxygen. While previous studies over short time periods (1 to 6 h) observed gas transfer velocity (k) to be more variable than pCO2aq, our work shows that over longer time (days to weeks) pCO2aq variability was greater and affected CO2 fluxes much more than k. We demonstrate that ≥8 measurement days distributed over multiple seasons in combination with sufficient spatial coverage (≥8 locations during stratification periods and 5 or less in spring and autumn) are a key for representative yearly whole lake flux estimates. This study illustrates the importance of considering spatiotemporal variability in pCO2aq and CO2 fluxes to generate representative whole lake estimates.

  8. How secure is subsurface CO2 storage? Controls on leakage in natural CO2 reservoirs

    NASA Astrophysics Data System (ADS)

    Miocic, Johannes; Gilfillan, Stuart; McDermott, Christopher; Haszeldine, Stuart

    2014-05-01

    Carbon Capture and Storage (CCS) is the only industrial scale technology available to directly reduce carbon dioxide (CO2) emissions from fossil fuelled power plants and large industrial point sources to the atmosphere. The technology includes the capture of CO2 at the source and transport to subsurface storage sites, such as depleted hydrocarbon reservoirs or saline aquifers, where it is injected and stored for long periods of time. To have an impact on the greenhouse gas emissions it is crucial that there is no or only a very low amount of leakage of CO2 from the storage sites to shallow aquifers or the surface. CO2 occurs naturally in reservoirs in the subsurface and has often been stored for millions of years without any leakage incidents. However, in some cases CO2 migrates from the reservoir to the surface. Both leaking and non-leaking natural CO2 reservoirs offer insights into the long-term behaviour of CO2 in the subsurface and on the mechanisms that lead to either leakage or retention of CO2. Here we present the results of a study on leakage mechanisms of natural CO2 reservoirs worldwide. We compiled a global dataset of 49 well described natural CO2 reservoirs of which six are leaking CO2 to the surface, 40 retain CO2 in the subsurface and for three reservoirs the evidence is inconclusive. Likelihood of leakage of CO2 from a reservoir to the surface is governed by the state of CO2 (supercritical vs. gaseous) and the pressure in the reservoir and the direct overburden. Reservoirs with gaseous CO2 is more prone to leak CO2 than reservoirs with dense supercritical CO2. If the reservoir pressure is close to or higher than the least principal stress leakage is likely to occur while reservoirs with pressures close to hydrostatic pressure and below 1200 m depth do not leak. Additionally, a positive pressure gradient from the reservoir into the caprock averts leakage of CO2 into the caprock. Leakage of CO2 occurs in all cases along a fault zone, indicating that

  9. How much CO2 is trapped in carbonate minerals of a natural CO2 occurrence?

    NASA Astrophysics Data System (ADS)

    Király, Csilla; Szabó, Zsuzsanna; Szamosfalvi, Ágnes; Cseresznyés, Dóra; Király, Edit; Szabó, Csaba; Falus, György

    2017-04-01

    Carbon Capture and Storage (CCS) is a transitional technology to decrease CO2 emissions from human fossil fuel usage and, therefore, to mitigate climate change. The most important criteria of a CO2 geological storage reservoir is that it must hold the injected CO2 for geological time scales without its significant seepage. The injected CO2 undergoes physical and chemical reactions in the reservoir rocks such as structural-stratigraphic, residual, dissolution or mineral trapping mechanisms. Among these, the safest is the mineral trapping, when carbonate minerals such as calcite, ankerite, siderite, dolomite and dawsonite build the CO2 into their crystal structures. The study of natural CO2 occurrences may help to understand the processes in CO2 reservoirs on geological time scales. This is the reason why the selected, the Mihályi-Répcelak natural CO2 occurrence as our research area, which is able to provide particular and highly significant information for the future of CO2 storage. The area is one of the best known CO2 fields in Central Europe. The main aim of this study is to estimate the amount of CO2 trapped in the mineral phase at Mihályi-Répcelak CO2 reservoirs. For gaining the suitable data, we apply petrographic, major and trace element (microprobe and LA-ICP-MS) and stable isotope analysis (mass spectrometry) and thermodynamic and kinetic geochemical models coded in PHREEQC. Rock and pore water compositions of the same formation, representing the pre-CO2 flooding stages of the Mihályi-Répcelak natural CO2 reservoirs are used in the models. Kinetic rate parameters are derived from the USGS report of Palandri and Kharaka (2004). The results of petrographic analysis show that a significant amount of dawsonite (NaAlCO3(OH)2, max. 16 m/m%) precipitated in the rock due to its reactions with CO2 which flooded the reservoir. This carbonate mineral alone traps about 10-30 kg/m3 of the reservoir rock from the CO2 at Mihályi-Répcelak area, which is an

  10. CO2 cooling in terrestrial planet thermospheres

    NASA Technical Reports Server (NTRS)

    Bougher, S. W.; Hunten, D. M.; Roble, R. G.

    1994-01-01

    We examine the recent progress in the debate on the CO2-O relaxation rate, its temperature dependence, and its corresponding impact on the thermospheric heat budgets of Venus, Earth, and Mars. This comparative approach provides the broadest range of conditions under which a common CO2-O relaxation rate should provide consistent results. New global mean calculations are presented for the heat budgets of these three planets using large CO2-O relaxation rates that have been inferred recently from Earth CO2 radiance measurements and laboratory studies. Results indicate that available Venus and Mars data constrain the CO2-O relaxation rate to be 2-4 x 10(exp -12)/cu cm/s at 300 K. For Venus, this strong cooling serves as an effective thermostat that gives rise to a small variation of thermospheric temperatures over the solar cycle, just as observed. Conversely, CO2 cooling does not appear to be dominant in the dayside heat budget of the Mars thermosphere over most of the solar cycle. For the Earth, this strong cooling implies that the lower thermosphere does not typically require significant eddy diffusion or heat conduction. However, global-scale dynamics or an additional heating mechanism may be needed to restore calculated temperatures to observed values when relaxation rates exceeding 2 x 10(exp -12)/cu cm/s are employed.

  11. CO2 Efflux from Cleared Mangrove Peat

    PubMed Central

    Lovelock, Catherine E.; Ruess, Roger W.; Feller, Ilka C.

    2011-01-01

    Background CO2 emissions from cleared mangrove areas may be substantial, increasing the costs of continued losses of these ecosystems, particularly in mangroves that have highly organic soils. Methodology/Principal Findings We measured CO2 efflux from mangrove soils that had been cleared for up to 20 years on the islands of Twin Cays, Belize. We also disturbed these cleared peat soils to assess what disturbance of soils after clearing may have on CO2 efflux. CO2 efflux from soils declines from time of clearing from ∼10 600 tonnes km−2 year−1 in the first year to 3000 tonnes km2 year−1 after 20 years since clearing. Disturbing peat leads to short term increases in CO2 efflux (27 umol m−2 s−1), but this had returned to baseline levels within 2 days. Conclusions/Significance Deforesting mangroves that grow on peat soils results in CO2 emissions that are comparable to rates estimated for peat collapse in other tropical ecosystems. Preventing deforestation presents an opportunity for countries to benefit from carbon payments for preservation of threatened carbon stocks. PMID:21738628

  12. Guard cell metabolism and CO2 sensing.

    PubMed

    Vavasseur, Alain; Raghavendra, Agepati S

    2005-03-01

    In this review we concentrate on guard cell metabolism and CO2 sensing. Although a matter of some controversy, it is generally accepted that the Calvin cycle plays a minor role in stomatal movements. Recent data emphasise the importance of guard cell starch degradation and of carbon import from the guard cell apoplast in promoting and maintaining stomatal opening. Chloroplast maltose and glucose transporters appear to be crucial to the export of carbon from both guard and mesophyll cells. The way guard cells sense CO2 remains an unresolved question. However, a better understanding of the cellular events downstream from CO2 sensing is emerging. We now recognise that there are common as well as unique steps in abscisic acid (ABA) and CO2 signalling pathways. For example, while ABA and CO2 both trigger increases in cytoplasmic free calcium, unlike ABA, CO2 does not promote a cytoplasmic pH change. Future advances in this area are likely to result from the increased use of techniques and resources, such as, reverse genetics, novel mutants, confocal imaging, and microarray analyses of the guard cell transcriptome.

  13. CO2 cooling in terrestrial planet thermospheres

    NASA Technical Reports Server (NTRS)

    Bougher, S. W.; Hunten, D. M.; Roble, R. G.

    1994-01-01

    We examine the recent progress in the debate on the CO2-O relaxation rate, its temperature dependence, and its corresponding impact on the thermospheric heat budgets of Venus, Earth, and Mars. This comparative approach provides the broadest range of conditions under which a common CO2-O relaxation rate should provide consistent results. New global mean calculations are presented for the heat budgets of these three planets using large CO2-O relaxation rates that have been inferred recently from Earth CO2 radiance measurements and laboratory studies. Results indicate that available Venus and Mars data constrain the CO2-O relaxation rate to be 2-4 x 10(exp -12)/cu cm/s at 300 K. For Venus, this strong cooling serves as an effective thermostat that gives rise to a small variation of thermospheric temperatures over the solar cycle, just as observed. Conversely, CO2 cooling does not appear to be dominant in the dayside heat budget of the Mars thermosphere over most of the solar cycle. For the Earth, this strong cooling implies that the lower thermosphere does not typically require significant eddy diffusion or heat conduction. However, global-scale dynamics or an additional heating mechanism may be needed to restore calculated temperatures to observed values when relaxation rates exceeding 2 x 10(exp -12)/cu cm/s are employed.

  14. CO2 Acquisition Membrane (CAM) Project

    NASA Technical Reports Server (NTRS)

    Mason, Larry W.

    2003-01-01

    The CO2 Acquisition Membrane (CAM) project was performed to develop, test, and analyze thin film membrane materials for separation and purification of carbon dioxide (CO2) from mixtures of gases, such as those found in the Martian atmosphere. The membranes developed in this project are targeted toward In Situ Resource Utilization (ISRU) applications, such as In Situ Propellant Production (ISPP) and In Situ Consumables Production (ISCP). These membrane materials may be used in a variety of ISRU systems, for example as the atmospheric inlet filter for an ISPP process to enhance the concentration of CO2 for use as a reactant gas, to passively separate argon and nitrogen trace gases from CO2 for habitat pressurization, to provide a system for removal of CO2 from breathing gases in a closed environment, or within a process stream to selectively separate CO2 from other gaseous components. The membranes identified and developed for CAM were evaluated for use in candidate ISRU processes and other gas separation applications, and will help to lay the foundation for future unmanned sample return and human space missions. CAM is a cooperative project split among three institutions: Lockheed Martin Astronautics (LMA), the Colorado School of Mines (CSM), and Marshall Space Flight Center (MSFC).

  15. Advanced CO2 Removal and Reduction System

    NASA Technical Reports Server (NTRS)

    Alptekin, Gokhan; Dubovik, Margarita; Copeland, Robert J.

    2011-01-01

    An advanced system for removing CO2 and H2O from cabin air, reducing the CO2, and returning the resulting O2 to the air is less massive than is a prior system that includes two assemblies . one for removal and one for reduction. Also, in this system, unlike in the prior system, there is no need to compress and temporarily store CO2. In this present system, removal and reduction take place within a single assembly, wherein removal is effected by use of an alkali sorbent and reduction is effected using a supply of H2 and Ru catalyst, by means of the Sabatier reaction, which is CO2 + 4H2 CH4 + O2. The assembly contains two fixed-bed reactors operating in alternation: At first, air is blown through the first bed, which absorbs CO2 and H2O. Once the first bed is saturated with CO2 and H2O, the flow of air is diverted through the second bed and the first bed is regenerated by supplying it with H2 for the Sabatier reaction. Initially, the H2 is heated to provide heat for the regeneration reaction, which is endothermic. In the later stages of regeneration, the Sabatier reaction, which is exothermic, supplies the heat for regeneration.

  16. Density of aqueous solutions of CO2

    SciTech Connect

    Garcia, Julio E.

    2001-10-10

    In this report, we present a numerical representation for the partial molar volume of CO2 in water and the calculation of the corresponding aqueous solution density. The motivation behind this work is related to the importance of having accurate representations for aqueous phase properties in the numerical simulation of carbon dioxide disposal into aquifers as well as in geothermal applications. According to reported experimental data the density of aqueous solutions of CO2 can be as much as 2-3% higher than pure water density. This density variation might produce an influence on the groundwater flow regime. For instance, in geologic sequestration of CO2, convective transport mixing might occur when, several years after injection of carbon dioxide has stopped, the CO2-rich gas phase is concentrated at the top of the formation, just below an overlaying caprock. In this particular case the heavier CO2 saturated water will flow downward and will be replaced by water with a lesser CO2 content.

  17. Airborne Dial Remote Sensing of the Arctic Ozone Layer

    NASA Technical Reports Server (NTRS)

    Wirth, Martin; Renger, Wolfgang; Ehret, Gerhard

    1992-01-01

    A combined ozone and aerosol LIDAR was developed at the Institute of Physics of the Atmosphere at the DLR in Oberpfaffenhofen. It is an airborne version, that, based on the DIAL-principle, permits the recording of two-dimensional ozone profiles. This presentation will focus on the ozone-part; the aerosol subsection will be treated later.

  18. USAFETAC Online Climatology: Dial-In Service Users Manual

    DTIC Science & Technology

    1994-02-01

    Chapter 2 GETTING STARTED AND LOGGING ON Fanllarzaton Dial-In was designed to operate both online and offline. Before you log on to the ETAC computer, we...o; -a:-] WV Local Time Conversion: [SS (- tar East. + tef Wesit ) "o Six-digit Block Station te. o. ,.r listing of 6W .,...,., Numbr conaltional *ow.n

  19. MediDial cards: a quick win for service improvement.

    PubMed

    Davies, Mike; Panchal, Sonia

    2014-01-01

    One of the key roles of a junior doctor is co-ordinating the care of their patients and communicating with different departments or specialties within the hospital. To do this, junior doctors often spend a lot of time on a daily basis contacting the hospital switchboard in order to locate a required bleep/extension/fax number, or trying to navigate an intranet based directory which can be difficult to use. We aimed to improve this task for junior doctors as a pilot project for engaging junior doctors in service improvement. Our multi-disciplinary team, led by junior doctors and with the support of the Trust, produced and implemented lanyard (MediDial) cards containing common and relevant (fax, bleep, and extension) numbers for use by junior doctors. Through the introduction of our MediDial cards we not only reduced the frequency junior doctors needed to contact the switchboard on a daily basis, but also the length of time spent waiting to speak to an operator. The MediDial cards were also found to be time saving and more useful than the previous intranet based database. Since the introduction of the MediDial cards, the project has been rolled out across the Trust and presented at Grand Rounds as an example of junior doctor led service improvement, aiming to encourage trainees to engage with quality improvement projects.

  20. Will atmospheric CO2 concentration continue to increase if anthropogenic CO2 emissions cease?

    NASA Astrophysics Data System (ADS)

    MacDougall, A. H.; Eby, M.; Weaver, A. J.

    2013-12-01

    If anthropogenic CO2 emissions were to suddenly cease, the evolution of the atmospheric CO2 concentration would depend on the magnitude and sign of natural carbon sources and sinks. Experiments using Earth system models indicate that overall carbon sinks would dominate. However, these models have typically neglected the permafrost carbon pool, which has the potential to introduce an additional terrestrial source of carbon to the atmosphere. Here we use the University of Victoria Earth System Climate Model, which has recently been expanded to include permafrost carbon stocks and exchanges with the atmosphere. In a scenario of zeroed CO2 and sulphate aerosol emissions, we assess whether the warming induced by specified constant concentrations of non-CO2 greenhouse gases could slow the CO2 decline following zero emissions, or even reverse this trend and cause CO2 to increase over time. We find that a radiative forcing from non-CO2 gases of approximately 0.6 W m-2 results in a near balance of CO2 emissions from the terrestrial biosphere and uptake of CO2 by the oceans, resulting in near-constant atmospheric CO2 concentrations for at least a century after emissions are eliminated. At higher values of non-CO2 radiative forcing, CO2 concentrations increase over time, regardless of when emissions cease during the 21st century. Given that the present-day radiative forcing from non-CO2 greenhouse gases is about 0.95 W m-2, our results suggest that if we were to eliminate all CO2 and aerosols emissions without also decreasing non-CO2 greenhouse gas emissions, CO2 levels would increase over time, resulting in a small increase in climate warming. The sudden and total cessation of anthropogenic CO2 emissions is an unlikely future scenario. However, such cessation experiments provide a useful method for evaluating the relative strength of the terrestrial and oceanic carbon cycle feedbacks in the presence of forcing from non-CO2 greenhouse gasses.

  1. Global CO2 simulation using GOSAT-based surface CO2 flux estimates

    NASA Astrophysics Data System (ADS)

    Takagi, H.; Oda, T.; Saito, M.; Valsala, V.; Belikov, D.; Saeki, T.; Saito, R.; Morino, I.; Uchino, O.; Yoshida, Y.; Yokota, Y.; Bril, A.; Oshchepkov, S.; Andres, R. J.; Maksyutov, S.

    2012-04-01

    Investigating the distribution and temporal variability of surface CO2 fluxes is an active research topic in the field of contemporary carbon cycle dynamics. The technique central to this effort is atmospheric inverse modeling with which surface CO2 fluxes are estimated by making corrections to a priori flux estimates such that mismatches between model-predicted and observed CO2 concentrations are minimized. Past investigations were carried out by utilizing CO2 measurements collected in global networks of surface-based monitoring sites. Now, datasets of column-averaged CO2 dry air mole fraction (XCO2) retrieved from spectral soundings collected by GOSAT are available for complementing the surface-based CO2 observations. These space-based XCO2 data are expected to enhance the spatiotemporal coverage of the existing surface observation network and thus reduce uncertainty associated with the surface flux estimates. We estimated monthly CO2 fluxes in 64 sub-continental regions from a subset of the surface-based GLOBALVIEW CO2 data and the GOSAT FTS SWIR Level 2 XCO2 retrievals. We further simulated CO2 concentrations in 3-D model space using the surface flux estimates obtained. In this presentation, we report the result of a comparison between the simulated CO2 concentrations and independent surface observations. As part of an effort in inter-comparing GOSAT-based surface CO2 flux estimates, we also look at results yielded with XCO2 data retrieved with the PPDF-DOAS algorithm and those made available by the NASA Atmospheric CO2 Observations from Space team. For this study, we used version 08.1 of the National Institute for Environmental Studies atmospheric transport model, which was driven by the Japan Meteorological Agency's JCDAS wind analysis data. The CO2 forward simulations were performed on 2.5° × 2.5° horizontal grids at 32 vertical levels between the surface and the top of the atmosphere. The a priori flux dataset used was comprised of the sum of four

  2. Commitment accounting for CO2 emissions

    NASA Astrophysics Data System (ADS)

    Davis, S. J.; Socolow, R. H.

    2013-12-01

    Long-lived energy infrastructure that burns fossil fuels represents a multi-decade 'commitment' to emit CO2. Today's global power sector, alone, represents hundreds of billions of tons of still unrealized 'committed emissions' of CO2. And every year, substantial new commitments to future emissions are made, as new power plants are built. The socioeconomic inertia of these commitments is a major barrier to climate change mitigation. Here, we quantify these annual commitments by a bottom-up analysis of all power plants commissioned between 1950 and 2011; assigning emission commitments to the year when each generator came on line. We find, assuming 40-year commitments, that the global commitment to future emissions from the world's generators in 2011 (the most recent year in our analysis) was 318 Gt CO2, of which 216 Gt CO2 were commitments from the world's coal-fired generators and 134 Gt CO2 were commitments from China's generators. Annual new global commitments exceeded 15 Gt CO2 per year in every year since 2000. Moreover, between 2005-2010 (the latest year of available emissions data), new global commitments were more than twice as large as actual emissions from all power plants. Country-specific ratios of new committed emissions to actual emissions, averaged over 1990-2010 were 4.1 for China, 2.6 for India, 0.9 for the EU, and 0.6 for the US. We urge that the reporting of annual CO2 emissions, already widely institutionalized, be augmented by 'commitment accounting' which makes these future emissions salient. Annual committed emissions and annual emissions of primary power infrastructure. New committed emissions (light green) have grown from approximately 4 Gt CO2 per year in 1960 to roughly 10 Gt CO2 per year between 1970-1995, and then to more than 15 Gt CO2 per year since 2000. Throughout this period, new committed emissions have exceeded annual emissions (blue curve, source: IEA). Although the commitments made 30-40 years ago have largely been realized (dark

  3. Precursory volcanic CO2 signals from space

    NASA Astrophysics Data System (ADS)

    Schwandner, Florian M.; Carn, Simon A.; Kataoka, Fumie; Kuze, Akihiko; Shiomi, Kei; Goto, Naoki

    2016-04-01

    Identification of earliest signals heralding volcanic unrest benefits from the unambiguous detection of precursors that reflect deviation of magmatic systems from metastable background activity. Ascent and emplacement of new basaltic magma at depth may precede eruptions by weeks to months. Transient localized carbon dioxide (CO2) emissions stemming from exsolution from depressurized magma are expected, and have been observed weeks to months ahead of magmatic surface activity. Detecting such CO2 precursors by continuous ground-based monitoring operations is unfortunately not a widely implemented method yet, save a handful of volcanoes. Detecting CO2 emissions from space offers obvious advantages - however it is technologically challenging, not the least due to the increasing atmospheric burden of CO2, against which a surface emission signal is hard to discern. In a multi-year project, we have investigated the feasibility of space-borne detection of pre-eruptive volcanic CO2 passive degassing signals using observations from the Greenhouse Gas Observing SATellite (GOSAT). Since 2010, we have observed over 40 active volcanoes from space using GOSAT's special target mode. Over 72% of targets experienced at least one eruption over that time period, demonstrating the potential utility of space-borne CO2 observations in non-imaging target-mode (point source monitoring mode). While many eruption precursors don't produce large enough CO2 signals to exceed space-borne detection thresholds of current satellite sensors, some of our observations have nevertheless already shown significant positive anomalies preceding eruptions at basaltic volcanoes. In 2014, NASA launched its first satellite dedicated to atmospheric CO2 observation, the Orbiting Carbon Observatory (OCO-2). Its observation strategy differs from the single-shot GOSAT instrument. At the expense of GOSAT's fast time series capability (3-day repeat cycle, vs. 16 for OCO-2), its 8-footprint continuous swath can slice

  4. Primary, secondary, and tertiary amines for CO2 capture: designing for mesoporous CO2 adsorbents.

    PubMed

    Ko, Young Gun; Shin, Seung Su; Choi, Ung Su

    2011-09-15

    CO(2) emissions, from fossil-fuel-burning power plants, the breathing, etc., influence the global worming on large scale and the man's work efficiency on small scale. The reversible capture of CO(2) is a prominent feature of CO(2) organic-inorganic hybrid adsorbent to sequester CO(2). Herein, (3-aminopropyl) trimethoxysilane (APTMS), [3-(methylamino)propyl] trimethoxysilane (MAPTMS), and [3-(diethylamino) propyl] trimethoxysilane (DEAPTMS) are immobilized on highly ordered mesoporous silicas (SBA-15) to catch CO(2) as primary, secondary, and tertiary aminosilica adsorbents. X-ray photoelectron spectroscopy was used to analyze the immobilized APTMS, MAPTMS, and DEAPTMS on the SBA-15. We report an interesting discovery that the CO(2) adsorption and desorption on the adsorbent depend on the amine type of the aminosilica adsorbent. The adsorbed CO(2) was easily desorbed from the adsorbent with the low energy consumption in the order of tertiary, secondary, and primary amino-adsorbents while the adsorption amount and the bonding-affinity increased in the reverse order. The effectiveness of amino-functionalized (1(o), 2(o), and 3(o) amines) SBA-15s as a CO(2) capturing agent was investigated in terms of adsorption capacity, adsorption-desorption kinetics, and thermodynamics. This work demonstrates apt amine types to catch CO(2) and regenerate the adsorbent, which may open new avenues to designing "CO(2) basket".

  5. Nepenthes pitchers are CO2-enriched cavities, emit CO2 to attract preys.

    PubMed

    Baby, Sabulal; Johnson, Anil John; Zachariah, Elavinamannil Jacob; Hussain, Abdul Azeez

    2017-09-12

    Carnivorous plants of the genus Nepenthes supplement their nutrient deficiency by capturing arthropods or by mutualistic interactions, through their leaf-evolved biological traps (pitchers). Though there are numerous studies on these traps, mostly on their prey capture mechanisms, the gas composition inside them remains unknown. Here we show that, Nepenthes unopened pitchers are CO2-enriched 'cavities', when open they emit CO2, and the CO2 gradient around open pitchers acts as a cue attracting preys towards them. CO2 contents in near mature, unopened Nepenthes pitchers were in the range 2500-5000 ppm. Gas collected from inside open N. khasiana pitchers showed CO2 at 476.75 ± 59.83 ppm. CO2-enriched air-streaming through N. khasiana pitchers (at 619.83 ± 4.53 ppm) attracted (captured) substantially higher number of aerial preys compared to air-streamed pitchers (CO2 at 412.76 ± 4.51 ppm). High levels of CO2 dissolved in acidic Nepenthes pitcher fluids were also detected. We demonstrate respiration as the source of elevated CO2 within Nepenthes pitchers. Most unique features of Nepenthes pitchers, viz., high growth rate, enhanced carbohydrate levels, declined protein levels, low photosynthetic capacity, high respiration rate and evolved stomata, are influenced by the CO2-enriched environment within them.

  6. Evaluation of CO2 Sorption Capacity of Granite for CO2 Geological Sequestration

    NASA Astrophysics Data System (ADS)

    Fujii, T.; Sato, Y.; Lin, H.; Sasaki, K.; Takahashi, T.; Inomata, H.; Hashida, T.

    2007-03-01

    Anthropogenic effects on climate can be mitigated through various measures. Among them being CO2 sequestration into geological reservoirs including deep saline aquifers, depleted oil/gas reservoirs and coal seams are interested in a powerful means for drastically reducing emissions of CO2. When CO2 would be injected into geological reservoir, it should be necessary to know the potential of CO2 storing into the reservoir. In this study, amount of CO2 sorption of granite was to evaluate experimentally at temperatures 50, 70, 100 and 200°C and pressure up to 20 MPa using a magnetic suspension balance (MSB), which allows to measure under supercritical condition. As a result, we confirmed that the granite have the potential of CO2 sorption. Sorption isotherms obtained from the MSB experiment showed that amount of CO2 sorption increased with the increasing pressure and decreased with the increasing temperature for all experimental conditions. Especially, amount of CO2 sorption at 50°C compared with that at other temperatures (70, 100 and 200°C) increased rapidly in the vicinity of the critical state. In addition, the granite showed a maximum of CO2 sorption into granite could reach up to about 1.0% by weight at 50°C and 14.4MPa. The present results may provide a fundamental knowledge for the development of CO2 geological sequestration technology.

  7. Fingerprinting captured CO2 using natural tracers: Determining CO2 fate and proving ownership

    NASA Astrophysics Data System (ADS)

    Flude, Stephanie; Gilfillan, Stuart; Johnston, Gareth; Stuart, Finlay; Haszeldine, Stuart

    2016-04-01

    In the long term, captured CO2 will most likely be stored in large saline formations and it is highly likely that CO2 from multiple operators will be injected into a single saline formation. Understanding CO2 behavior within the reservoir is vital for making operational decisions and often uses geochemical techniques. Furthermore, in the event of a CO2 leak, being able to identify the owner of the CO2 is of vital importance in terms of liability and remediation. Addition of geochemical tracers to the CO2 stream is an effective way of tagging the CO2 from different power stations, but may become prohibitively expensive at large scale storage sites. Here we present results from a project assessing whether the natural isotopic composition (C, O and noble gas isotopes) of captured CO2 is sufficient to distinguish CO2 captured using different technologies and from different fuel sources, from likely baseline conditions. Results include analytical measurements of CO2 captured from a number of different CO2 capture plants and a comprehensive literature review of the known and hypothetical isotopic compositions of captured CO2 and baseline conditions. Key findings from the literature review suggest that the carbon isotope composition will be most strongly controlled by that of the feedstock, but significant fractionation is possible during the capture process; oxygen isotopes are likely to be controlled by the isotopic composition of any water used in either the industrial process or the capture technology; and noble gases concentrations will likely be controlled by the capture technique employed. Preliminary analytical results are in agreement with these predictions. Comparison with summaries of likely storage reservoir baseline and shallow or surface leakage reservoir baseline data suggests that C-isotopes are likely to be valuable tracers of CO2 in the storage reservoir, while noble gases may be particularly valuable as tracers of potential leakage.

  8. Exercise carbon dioxide (CO2) retention with inhaled CO2 and breathing resistance.

    PubMed

    Shykoff, Barbara E; Warkander, Dan E

    2012-01-01

    Combined effects on respiratory minute ventilation (VE)--and thus, on end-tidal carbon dioxide partial pressure (P(ET)CO2)--of breathing resistance and elevated inspired carbon dioxide (CO2) had not been determined during heavy exercise. In this Institutional Review Board-approved, dry, sea-level study, 12 subjects in each of three phases exercised to exhaustion at 85% peak oxygen uptake while V(E) and P(ET)CO2 were measured. Participants inhaled 0%, 1%, 2% or 3% CO2 in air, or 0% or 2% CO2 in oxygen, with or without breathing resistance, mimicking the U.S. Navy's MK 16 rebreather underwater breathing apparatus (UBA). Compared to air baseline (0% inspired CO2 in air without resistance): (1) Oxygen decreased baseline V(E) (p < 0.01); (2) Inspired CO2 increased V(E) and P(ET)CO2 (p < 0.01); (3) Resistance decreased V(E) (p < 0.01); (4) Inspired CO2 with resistance elevated P(ET)CO2 (p < 0.01). In air, V(E) did not change from that with resistance alone. In oxygen, V(E) returned to oxygen baseline. End-exercise P(ET)CO2 exceeded 60 Torr (8.0 kPa) in three tests. Subjects identified hypercapnia poorly. Results support dual optimization of arterial carbon dioxide partial pressure and respiratory effort. Because elevated CO2 may not increase V(E) if breathing resistance and VE are high, rebreather UBA safety requires very low inspired CO2.

  9. Wavelength Scanning Employing the Return to Zero Modulation Technique to Retrieve Atmospheric CO2 Profiles

    NASA Astrophysics Data System (ADS)

    Burris, J., Jr.

    2014-12-01

    The ability to make range resolved measurements of CO2 in the lower atmosphere is critical to helping understand regional scale sources and sinks while providing data essential for validating the future ASCENDS mission. The Return-to-Zero Pseudo Noise modulation technique has been explored for making range resolved retrievals of CO2 within the lower troposphere using commercial off the shelf technology. It generates multiple laser pulses within the detector's field of view while still enabling range resolved measurements. This permits a much higher duty cycle to be achieved than if using a normal pulsed laser. Because of issues relating to how this technique treats background counts a different approach to the conventional DIAL online/offline has been explored. This involves stepping over an absorption line using a number of discrete wavelengths to map out the line. The data is then fit to a theoretical curve which permits the accurate determination of CO2 over the path. This approach is similar in implementation to that employed by the Goddard ASCENDS instrument except that the laser is now modulated with the RZPN technique. An assessment of this approach with particular emphasis on how it treats background counts will be discussed.

  10. Advanced CO2 Removal Technology Development

    NASA Technical Reports Server (NTRS)

    Finn, John E.; Verma, Sunita; Forrest, Kindall; LeVan, M. Douglas

    2001-01-01

    The Advanced CO2 Removal Technical Task Agreement covers three active areas of research and development. These include a study of the economic viability of a hybrid membrane/adsorption CO2 removal system, sorbent materials development, and construction of a database of adsorption properties of important fixed gases on several adsorbent material that may be used in CO2 removal systems. The membrane/adsorption CO2 removal system was proposed as a possible way to reduce the energy consumption of the four-bed molecular sieve system now in use. Much of the energy used by the 4BMS is used to desorb water removed in the device s desiccant beds. These beds might be replaced by a desiccating membrane that moves the water from [he incoming stream directly into the outlet stream. The approach may allow the CO2 removal beds to operate at a lower temperature. A comparison between models of the 4BMS and hybrid systems is underway at Vanderbilt University. NASA Ames Research Center has been investigating a Ag-exchanged zeolites as a possible improvement over currently used Ca and Na zeolites for CO2 removal. Silver ions will complex with n:-bonds in hydrocarbons such as ethylene, giving remarkably improved selectivity for adsorption of those materials. Bonds with n: character are also present in carbon oxides. NASA Ames is also continuing to build a database for adsorption isotherms of CO2, N2, O2, CH4, and Ar on a variety of sorbents. This information is useful for analysis of existing hardware and design of new processes.

  11. Photolytic production of CO2 on Iapetus

    NASA Astrophysics Data System (ADS)

    Palmer, Eric; Brown, R. H.

    2008-09-01

    Carbon Dioxide has been detected on the surface of Iapetus by Cassini's VIMS instrument at the 4.26 micron band. This CO2 is concentrated on the equatorial leading side, where we also see an abundance of dark material. The residence time of free CO2 on the surface of Iapetus is very short, thus the CO2 is unlikely to be in the form of frost; it is more likely that the CO2 is tightly bound in the form of complexed molecules. We explore the possibility of photolytically generating CO2 from a mixture of the carbon rich material and water ice that matches the expected composition of the dark material on Iapetus' surface. An ice regolith was created with flash frozen water that was crushed into sub-millimeter shards and mixed with amorphous 13C. The regolith was placed in a vacuum chamber with a surface area of 10 cm2 and a thickness of 2 cm and exposed to UV light from a deuterium lamp with peaks of flux centered around 121 and 160 nm. Temperatures were varied between 60 and 130K at a pressure of 10-8 torr. Both CO and CO2 were produced by photolytic reactions and detected by a mass spectrometer. Applying these results to Iapetus, Jeans escape calculations show that CO2 generated by photolysis will remain gravitationally bound to Iapetus for between 100 and 200 years, ballistically scattering across the surface until it is sequestered in a polar cold trap or escapes to space. The average particle will interact with the surface more than 1000 times before escaping unless interactions with surface grains causes it to become complexed, such as adsorption. We are continuing to evaluate the photochemistry for this simulated Iapetus surface using a Nicolet IR spectrometer to identify all the products generated and estimate the associated production rate.

  12. Advanced CO2 Removal Technology Development

    NASA Technical Reports Server (NTRS)

    Finn, John E.; Verma, Sunita; Forrest, Kindall; LeVan, M. Douglas

    2001-01-01

    The Advanced CO2 Removal Technical Task Agreement covers three active areas of research and development. These include a study of the economic viability of a hybrid membrane/adsorption CO2 removal system, sorbent materials development, and construction of a database of adsorption properties of important fixed gases on several adsorbent material that may be used in CO2 removal systems. The membrane/adsorption CO2 removal system was proposed as a possible way to reduce the energy consumption of the four-bed molecular sieve system now in use. Much of the energy used by the 4BMS is used to desorb water removed in the device s desiccant beds. These beds might be replaced by a desiccating membrane that moves the water from [he incoming stream directly into the outlet stream. The approach may allow the CO2 removal beds to operate at a lower temperature. A comparison between models of the 4BMS and hybrid systems is underway at Vanderbilt University. NASA Ames Research Center has been investigating a Ag-exchanged zeolites as a possible improvement over currently used Ca and Na zeolites for CO2 removal. Silver ions will complex with n:-bonds in hydrocarbons such as ethylene, giving remarkably improved selectivity for adsorption of those materials. Bonds with n: character are also present in carbon oxides. NASA Ames is also continuing to build a database for adsorption isotherms of CO2, N2, O2, CH4, and Ar on a variety of sorbents. This information is useful for analysis of existing hardware and design of new processes.

  13. Carbon Dioxide Clusters: (CO_2)_6 to (CO_2)13

    NASA Astrophysics Data System (ADS)

    McKellar, A. R. W.; Oliaee, J. Norooz; Dehghany, M.; Moazzen-Ahmadi, N.

    2011-06-01

    We recenty reported assignments of specific infrared bands in the CO_2 νb{3} region (˜2350 wn) to (CO_2)_6, (CO_2)_7, (CO_2)_9, (CO_2)10, (CO_2)11, (CO_2)12, and (CO_2)13. Spectra are obtained by direct absorption using a rapid-scan tuneable diode laser spectrometer to probe a pulsed supersonic slit-jet expansion and assignments are facilitated by recent calculations of Takeuchi based on the Murthy potential. (CO_2)_6 is a symmetric top with S_6 point group symmetry which can be thought of as a stack of two planar cyclic trimers. (CO_2)13 is also an S_6 symmetric top, and consists of a single CO_2 monomer surrounded by an slightly distorted icosahedral cage. The remaining clusters are asymmetric tops without symmetry. Here we report additional CO_2 cluster results. Calculations based on the SAPT-s potential indicate that the structure of (CO_2)10 may be slightly different from that given by Takeuchi/Murthy. An additional band is observed for each of (CO_2)13 and (CO_2)10. A feature observed at 2378.2 wn is assigned as a (CO_2)_6 parallel combination band involving the sum of a fundamental and a low-lying intermolecular vibration. Most significantly, two bands are assigned to a second isomer of (CO_2)_6. This is also a symmetric top, but now with S_4 symmetry. The two symmetric hexamer isomers observed spectroscopically correspond well with the lowest energy structures given by both the SAPT-s and Murthy intermolecular potentials. [1] J. Norooz Oliaee, M. Dehgany, N. Moazzen-Ahmadi, and A.R.W. McKellar, Phys. Chem. Chem. Phys. 13, 1297 (2011). [2] H. Takeuchi, J. Phys. Chem. A 107, 5703 (2008); C.S. Murthy, S.F. O'Shea, and I.R. McDonald, Mol. Phys. 50, 531 (1983). [3] R. Bukowski, J. Sadlej, B. Jeziorski, P. Jankowski, K. Szalewicz, S.A. Kucharski, H.L. Williams, and B.M. Rice, J. Chem. Phys. 110, 3785 (1999)

  14. CO2-Water-Rock Wettability: Variability, Influencing Factors, and Implications for CO2 Geostorage.

    PubMed

    Iglauer, Stefan

    2017-05-16

    Carbon geosequestration (CGS) has been identified as a key technology to reduce anthropogenic greenhouse gas emissions and thus significantly mitigate climate change. In CGS, CO2 is captured from large point-source emitters (e.g., coal fired power stations), purified, and injected deep underground into geological formations for disposal. However, the CO2 has a lower density than the resident formation brine and thus migrates upward due to buoyancy forces. To prevent the CO2 from leaking back to the surface, four trapping mechanisms are used: (1) structural trapping (where a tight caprock acts as a seal barrier through which the CO2 cannot percolate), (2) residual trapping (where the CO2 plume is split into many micrometer-sized bubbles, which are immobilized by capillary forces in the pore network of the rock), (3) dissolution trapping (where CO2 dissolves in the formation brine and sinks deep into the reservoir due to a slight increase in brine density), and (4) mineral trapping (where the CO2 introduced into the subsurface chemically reacts with the formation brine or reservoir rock or both to form solid precipitates). The efficiency of these trapping mechanisms and the movement of CO2 through the rock are strongly influenced by the CO2-brine-rock wettability (mainly due to the small capillary-like pores in the rock which form a complex network), and it is thus of key importance to rigorously understand CO2-wettability. In this context, a substantial number of experiments have been conducted from which several conclusions can be drawn: of prime importance is the rock surface chemistry, and hydrophilic surfaces are water-wet while hydrophobic surfaces are CO2-wet. Note that CO2-wet surfaces dramatically reduce CO2 storage capacities. Furthermore, increasing pressure, salinity, or dissolved ion valency increases CO2-wettability, while the effect of temperature is not well understood. Indeed theoretical understanding of CO2-wettability and the ability to

  15. Correction function in the Lidar equation and the solution techniques for CO2 Lidar date reduction

    NASA Technical Reports Server (NTRS)

    Zhao, Y.; Lea, T. K.; Schotland, R. M.

    1986-01-01

    For lidar systems with long laser pulses the unusual behavior of the near-range signals causes serious difficulties and large errors in reduction. The commonly used lidar equation is no longer applicable since the convolution of the laser pulse with the atmospheric parameter distributions should be taken into account. It is important to give more insight into this problem and find the solution techniques. Starting from the original equation, a general form is suggested for the single scattering lidar equation where a correction function Cr is introduced. The correction Function Cr(R) derived from the original equation indicates the departure from the normal lidar equation. Examples of Cr(R) for a coaxial CO2 lidar system are presented. The Differential Absorption Lidar (DIAL) errors caused by the differences of Cr(R) for H2O measurements are plotted against height.

  16. CO2 and CO Simulations and Their Source Signature Indicated by CO/CO2

    NASA Technical Reports Server (NTRS)

    Kawa, Randy; Huisheng, Bian

    2004-01-01

    Three years (2000-2002) atmospheric CO2 and CO fields are simulated by a Chemistry Transport Model driven by the assimilated meteorological fields from GEOS-4. The simulated CO2 and CO are evaluated by measurements from surface (CMDL), satellite (MOPITT/CO), and aircraft. The model-observation comparisons indicate reasonable agreement in both source and remote regions, and in the lower and upper troposphere. The simulation also captures the seasonality of CO2 and CO variations. The ratios of CO/CO2 are analyzed over different representative regions to identify the source signature, since the anthropogenic CO comes fiom the same combustion processes as CO2. This work enables us to improve satellite inversion estimates of CO2 sources and sinks by simultaneously using satellite CO measurement.

  17. CO2 and CO Simulations and Their Source Signature Indicated by CO/CO2

    NASA Technical Reports Server (NTRS)

    Kawa, Randy; Huisheng, Bian

    2004-01-01

    Three years (2000-2002) atmospheric CO2 and CO fields are simulated by a Chemistry Transport Model driven by the assimilated meteorological fields from GEOS-4. The simulated CO2 and CO are evaluated by measurements from surface (CMDL), satellite (MOPITT/CO), and aircraft. The model-observation comparisons indicate reasonable agreement in both source and remote regions, and in the lower and upper troposphere. The simulation also captures the seasonality of CO2 and CO variations. The ratios of CO/CO2 are analyzed over different representative regions to identify the source signature, since the anthropogenic CO comes fiom the same combustion processes as CO2. This work enables us to improve satellite inversion estimates of CO2 sources and sinks by simultaneously using satellite CO measurement.

  18. CO2 sensing and CO2 regulation of stomatal conductance: advances and open questions

    PubMed Central

    Engineer, Cawas; Hashimoto-Sugimoto, Mimi; Negi, Juntaro; Israelsson-Nordstrom, Maria; Azoulay-Shemer, Tamar; Rappel, Wouter-Jan; Iba, Koh; Schroeder, Julian

    2015-01-01

    Guard cells form epidermal stomatal gas exchange valves in plants and regulate the aperture of stomatal pores in response to changes in the carbon dioxide (CO2) concentration in leaves. Moreover, the development of stomata is repressed by elevated CO2 in diverse plant species. Evidence suggests that plants can sense CO2 concentration changes via guard cells and via mesophyll tissues in mediating stomatal movements. We review new discoveries and open questions on mechanisms mediating CO2-regulated stomatal movements and CO2 modulation of stomatal development, which together function in CO2-regulation of stomatal conductance and gas exchange in plants. Research in this area is timely in light of the necessity of selecting and developing crop cultivars which perform better in a shifting climate. PMID:26482956

  19. Validation of Airborne CO2 Laser Measurements

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    This paper discusses the flight test validation of a unique, multi-frequency, intensity-modulated, single-beam laser absorption spectrometer (LAS) that operates near 1.57 μm for remote column CO2 measurements. This laser system is under development for a future space-based mission to determine the global distribution of regional-scale CO2 sources and sinks, which is the objective of the NASA Active Sensing of CO2 Emissions during Nights, Days, and Seasons (ASCENDS) mission. A prototype of this LAS system, called the Multi-frequency Fiber Laser Lidar (MFLL), was developed by ITT, and it has been flight tested in nine airborne campaigns since May 2005. This paper focuses on the most recent results obtained over the last two years of flight-testing where the MFLL remote CO2 column measurements were evaluated against airborne in situ CO2 profile measurements traceable to World Meteorological Organization standards. A comprehensive multiple-aircraft flight test program was conducted over Oklahoma and Virginia in July-August 2009. The MFLL obtained surface reflectance and average CO2 column variations along the 50-km flight legs over the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Central Facility (CF) in Lamont, Oklahoma; over rural Virginia and North Carolina; and over the Chesapeake Bay. For a flight altitude of 4.6 km, the average signal to noise ratio (SNR) for a 1-s CO2 column measurement was found to be 760, which is the equivalent of a CO2 mixing ratio precision of 0.60 ppmv, and for a 10-s average the SNR was found to be 2002 or 0.20 ppmv. Absolute comparisons of MFLL-derived and in situ-derived CO2 column measurements were made for all daytime flights conducted over Oklahoma and Virginia with an average agreement to within 0.32 ppmv. A major ASCENDS flight test campaign was conducted using the NASA DC-8 during 6-18 July 2010. The MFLL system and associated in situ CO2 instrumentation were operated on DC-8 flights over the Central Valley

  20. Monitoring of near surface CO2

    NASA Astrophysics Data System (ADS)

    Faber, E.; Möller, I.; Teschner, M.; Poggenburg, J.; Spickenbom, K.; Schulz, H. J.

    2009-04-01

    Monitoring of near surface CO2 ECKHARD FABER1, INGO MÖLLER1, MANFRED TESCHNER1, JÜRGEN POGGENBURG1, KAI SPICKENBOM1, HANS-MARTIN SCHULZ1,2 1Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Stilleweg 2, D-30655 Hannover, e.faber@bgr.de 2present adress: GeoForschungsZentrum Potsdam (GFZ), Telegrafenberg, D-14473 Potsdam Underground gas storage and sequestration of carbon dioxide is one of the methods to reduce the input of antropogenic CO2 into the atmosphere and its greenhouse effect. Storage of CO2 is planned in depleted reservoirs, in aquifers and in salt caverns. Storage sites must have very small leakage rates to safely store the CO2 for centuries. Thus, a careful investigation and site selection is crucial. However, any leakage of CO2 to the surface is potentially dangerous for humans and environment. Therefore, instruments and systems for the detection of any CO2 escaping the storage sites and reaching the atmosphere have to be developed. Systems to monitor gases in deep wells, groundwater and surface sediments for leaking CO2 are developed, tested and are contnuously improved. Our group is mainly analysing CO2 in shallow (down to 3 m) soil samples using automatically operating monitoring systems. The systems are equipped with sensors to measure CO2 (and other gases) concentrations and other environmental parameters (atmospheric pressure, ambient and soil temperatures, etc.). Data are measured in short intervals (minute to subminute), are stored locally and are transferred by telemetrical systems into the BGR laboratory (Weinlich et al., 2006). In addition to soil gases monitoring systems technical equipment is available for continuous underwater gas flow measurements. Several of those monitoring systems are installed in different areas like Czech Republic, Austria, Italy and Germany. To detect any leaking gas from a sequestration site after CO2 injection, the naturally existing CO2 concentration (before injection) must be known. Thus, the natural

  1. Direct Copolymerization of CO2 and Diols

    PubMed Central

    Tamura, Masazumi; Ito, Kazuki; Honda, Masayoshi; Nakagawa, Yoshinao; Sugimoto, Hiroshi; Tomishige, Keiichi

    2016-01-01

    Direct polymerization of CO2 and diols is promising as a simple and environmental-benign method in place of conventional processes using high-cost and/or hazardous reagents such as phosgene, carbon monoxide and epoxides, however, there are no reports on the direct method due to the inertness of CO2 and severe equilibrium limitation of the reaction. Herein, we firstly substantiate the direct copolymerization of CO2 and diols using CeO2 catalyst and 2-cyanopyridine promotor, providing the alternating cooligomers in high diol-based yield (up to 99%) and selectivity (up to >99%). This catalyst system is applicable to various diols including linear C4-C10 α,ω-diols to provide high yields of the corresponding cooligomers, which cannot be obtained by well-known methods such as copolymerization of CO2 and cyclic ethers and ring-opening polymerization of cyclic carbonates. This process provides us a facile synthesis method for versatile polycarbonates from various diols and CO2 owing to simplicity of diols modification. PMID:27075987

  2. The supply chain of CO2 emissions

    PubMed Central

    Davis, Steven J.; Peters, Glen P.; Caldeira, Ken

    2011-01-01

    CO2 emissions from the burning of fossil fuels are conventionally attributed to the country where the emissions are produced (i.e., where the fuels are burned). However, these production-based accounts represent a single point in the value chain of fossil fuels, which may have been extracted elsewhere and may be used to provide goods or services to consumers elsewhere. We present a consistent set of carbon inventories that spans the full supply chain of global CO2 emissions, finding that 10.2 billion tons CO2 or 37% of global emissions are from fossil fuels traded internationally and an additional 6.4 billion tons CO2 or 23% of global emissions are embodied in traded goods. Our results reveal vulnerabilities and benefits related to current patterns of energy use that are relevant to climate and energy policy. In particular, if a consistent and unavoidable price were imposed on CO2 emissions somewhere along the supply chain, then all of the parties along the supply chain would seek to impose that price to generate revenue from taxes collected or permits sold. The geographical concentration of carbon-based fuels and relatively small number of parties involved in extracting and refining those fuels suggest that regulation at the wellhead, mine mouth, or refinery might minimize transaction costs as well as opportunities for leakage. PMID:22006314

  3. Direct Copolymerization of CO2 and Diols

    NASA Astrophysics Data System (ADS)

    Tamura, Masazumi; Ito, Kazuki; Honda, Masayoshi; Nakagawa, Yoshinao; Sugimoto, Hiroshi; Tomishige, Keiichi

    2016-04-01

    Direct polymerization of CO2 and diols is promising as a simple and environmental-benign method in place of conventional processes using high-cost and/or hazardous reagents such as phosgene, carbon monoxide and epoxides, however, there are no reports on the direct method due to the inertness of CO2 and severe equilibrium limitation of the reaction. Herein, we firstly substantiate the direct copolymerization of CO2 and diols using CeO2 catalyst and 2-cyanopyridine promotor, providing the alternating cooligomers in high diol-based yield (up to 99%) and selectivity (up to >99%). This catalyst system is applicable to various diols including linear C4-C10 α,ω-diols to provide high yields of the corresponding cooligomers, which cannot be obtained by well-known methods such as copolymerization of CO2 and cyclic ethers and ring-opening polymerization of cyclic carbonates. This process provides us a facile synthesis method for versatile polycarbonates from various diols and CO2 owing to simplicity of diols modification.

  4. The supply chain of CO2 emissions.

    PubMed

    Davis, Steven J; Peters, Glen P; Caldeira, Ken

    2011-11-08

    CO(2) emissions from the burning of fossil fuels are conventionally attributed to the country where the emissions are produced (i.e., where the fuels are burned). However, these production-based accounts represent a single point in the value chain of fossil fuels, which may have been extracted elsewhere and may be used to provide goods or services to consumers elsewhere. We present a consistent set of carbon inventories that spans the full supply chain of global CO(2) emissions, finding that 10.2 billion tons CO(2) or 37% of global emissions are from fossil fuels traded internationally and an additional 6.4 billion tons CO(2) or 23% of global emissions are embodied in traded goods. Our results reveal vulnerabilities and benefits related to current patterns of energy use that are relevant to climate and energy policy. In particular, if a consistent and unavoidable price were imposed on CO(2) emissions somewhere along the supply chain, then all of the parties along the supply chain would seek to impose that price to generate revenue from taxes collected or permits sold. The geographical concentration of carbon-based fuels and relatively small number of parties involved in extracting and refining those fuels suggest that regulation at the wellhead, mine mouth, or refinery might minimize transaction costs as well as opportunities for leakage.

  5. Atmospheric CO2 stabilization and ocean acidification

    NASA Astrophysics Data System (ADS)

    Cao, Long; Caldeira, Ken

    2008-10-01

    We use a coupled climate/carbon-cycle model to examine the consequences of stabilizing atmospheric CO2 at different levels for ocean chemistry. Our simulations show the potential for major damage to at least some ocean ecosystems at atmospheric CO2 stabilization levels as low as 450 ppm. Before the industrial revolution, more than 98% of corals reefs were surrounded by waters that were >3.5 times saturated with respect to their skeleton materials (aragonite). If atmospheric CO2 is stabilized at 450 ppm only 8% of existing coral reefs will be surrounded by water with this saturation level. Also at this CO2 level 7% of the ocean South of 60°S will become undersaturated with respect to aragonite, and parts of the high latitude ocean will experience a decrease in pH by more than 0.2 units. Results presented here provide an independent and additional basis for choosing targets of atmospheric CO2 stabilization levels.

  6. A Doppler lidar with CO2-laser intracavity detection

    NASA Astrophysics Data System (ADS)

    Godlevskii, A. P.; Gordov, E. P.; Zhiliba, A. I.; Sharin, P. P.

    A version of a high-sensitive Doppler lidar, based on intracavity coherent laser detection is described. The device consists of a CO2 laser, transmitting-receiving optical system, and signal-processing unit. Laser-intensity stabilization is achieved by decreasing the mechanical disturbance of the laser resonator, and the optical tract is formed by a Cassegrain telescope. A portion of the laser beam reflected back by a Breuster window of the gas discharge tube is focused by a spherical mirror onto a photodetector. Results of laboratory and real-atmosphere experiments are reported, and it is shown that vibrations of a retroreflector with an amplitude of 50 micron are detected at distances up to 500 m.

  7. CO2 efflux, CO2 concentration and photosynthetic refixation in stems of Eucalyptus globulus (Labill.).

    PubMed

    Cerasoli, S; McGuire, M A; Faria, J; Mourato, M; Schmidt, M; Pereira, J S; Chaves, M M; Teskey, R O

    2009-01-01

    In spite of the importance of respiration in forest carbon budgets, the mechanisms by which physiological factors control stem respiration are unclear. An experiment was set up in a Eucalyptus globulus plantation in central Portugal with monoculture stands of 5-year-old and 10-year-old trees. CO(2) efflux from stems under shaded and unshaded conditions, as well as the concentration of CO(2) dissolved in sap [CO(2)(*)], stem temperature, and sap flow were measured with the objective of improving our understanding of the factors controlling CO(2) release from stems of E. globulus. CO(2) efflux was consistently higher in 5-year-old, compared with 10-year-old, stems, averaging 3.4 versus 1.3 mumol m(-2) s(-1), respectively. Temperature and [CO(2)(*)] both had important, and similar, influences on the rate of CO(2) efflux from the stems, but neither explained the difference in the magnitude of CO(2) efflux between trees of different age and size. No relationship was found between efflux and sap flow, and efflux was independent of tree volume, suggesting the presence of substantial barriers to the diffusion of CO(2) from the xylem to the atmosphere in this species. The rate of corticular photosynthesis was the same in trees of both ages and only reduced CO(2) efflux by 7%, probably due to the low irradiance at the stem surface below the canopy. The younger trees were growing at a much faster rate than the older trees. The difference between CO(2) efflux from the younger and older stems appears to have resulted from a difference in growth respiration rather than a difference in the rate of diffusion of xylem-transported CO(2).

  8. pCO2 and CO2 Exchange During High Bora Winds in the Northern Adriatic

    DTIC Science & Technology

    2013-03-05

    coastal ocean , has not been adequately assessed. Here we show the response of surfacewater pCO2 and CO2 fluxes during high borawind in the Northern...m−2 day−1 day in thewinter cases and 29 mmol m−2 day−1 in the summer case) over themag- nitude of the mean annual value. Oceanic data measured...simultaneously to surface pCO2 measurements suggest that themost likely responsiblemechanisms for the observed pCO2 increaseswere oceanic verticalmixing and

  9. The Abundance of Atmospheric CO2 in Ocean Exoplanets: a Novel CO2 Deposition Mechanism

    NASA Astrophysics Data System (ADS)

    Levi, A.; Sasselov, D.; Podolak, M.

    2017-03-01

    We consider super-Earth sized planets which have a water mass fraction large enough to form an external mantle composed of high-pressure water-ice polymorphs and also lack a substantial H/He atmosphere. We consider such planets in their habitable zone, so that their outermost condensed mantle is a global, deep, liquid ocean. For these ocean planets, we investigate potential internal reservoirs of CO2, the amount of CO2 dissolved in the ocean for the various saturation conditions encountered, and the ocean-atmosphere exchange flux of CO2. We find that, in a steady state, the abundance of CO2 in the atmosphere has two possible states. When wind-driven circulation is the dominant CO2 exchange mechanism, an atmosphere of tens of bars of CO2 results, where the exact value depends on the subtropical ocean surface temperature and the deep ocean temperature. When sea-ice formation, acting on these planets as a CO2 deposition mechanism, is the dominant exchange mechanism, an atmosphere of a few bars of CO2 is established. The exact value depends on the subpolar surface temperature. Our results suggest the possibility of a negative feedback mechanism, unique to water planets, where a reduction in the subpolar temperature drives more CO2 into the atmosphere to increase the greenhouse effect.

  10. Behavior of CO2/water flow in porous media for CO2 geological storage.

    PubMed

    Jiang, Lanlan; Yu, Minghao; Liu, Yu; Yang, Mingjun; Zhang, Yi; Xue, Ziqiu; Suekane, Tetsuya; Song, Yongchen

    2017-04-01

    A clear understanding of two-phase fluid flow properties in porous media is of importance to CO2 geological storage. The study visually measured the immiscible and miscible displacement of water by CO2 using MRI (magnetic resonance imaging), and investigated the factor influencing the displacement process in porous media which were filled with quartz glass beads. For immiscible displacement at slow flow rates, the MR signal intensity of images increased because of CO2 dissolution; before the dissolution phenomenon became inconspicuous at flow rate of 0.8mLmin(-1). For miscible displacement, the MR signal intensity decreased gradually independent of flow rates, because supercritical CO2 and water became miscible in the beginning of CO2 injection. CO2 channeling or fingering phenomena were more obviously observed with lower permeable porous media. Capillary force decreases with increasing particle size, which would increase permeability and allow CO2 and water to invade into small pore spaces more easily. The study also showed CO2 flow patterns were dominated by dimensionless capillary number, changing from capillary finger to stable flow. The relative permeability curve was calculated using Brooks-Corey model, while the results showed the relative permeability of CO2 slightly decreases with the increase of capillary number.

  11. Light-duty vehicle CO2 targets consistent with 450 ppm CO2 stabilization.

    PubMed

    Winkler, Sandra L; Wallington, Timothy J; Maas, Heiko; Hass, Heinz

    2014-06-03

    We present a global analysis of CO2 emission reductions from the light-duty vehicle (LDV) fleet consistent with stabilization of atmospheric CO2 concentration at 450 ppm. The CO2 emission reductions are described by g CO2/km emission targets for average new light-duty vehicles on a tank-to-wheel basis between 2010 and 2050 that we call CO2 glide paths. The analysis accounts for growth of the vehicle fleet, changing patterns in driving distance, regional availability of biofuels, and the changing composition of fossil fuels. New light-duty vehicle fuel economy and CO2 regulations in the U.S. through 2025 and in the EU through 2020 are broadly consistent with the CO2 glide paths. The glide path is at the upper end of the discussed 2025 EU range of 68-78 g CO2/km. The proposed China regulation for 2020 is more stringent than the glide path, while the 2017 Brazil regulation is less stringent. Existing regulations through 2025 are broadly consistent with the light-duty vehicle sector contributing to stabilizing CO2 at approximately 450 ppm. The glide paths provide long-term guidance for LDV powertrain/fuel development.

  12. Metal-CO2 Batteries on the Road: CO2 from Contamination Gas to Energy Source.

    PubMed

    Xie, Zhaojun; Zhang, Xin; Zhang, Zhang; Zhou, Zhen

    2017-04-01

    Rechargeable nonaqueous metal-air batteries attract much attention for their high theoretical energy density, especially in the last decade. However, most reported metal-air batteries are actually operated in a pure O2 atmosphere, while CO2 and moisture in ambient air can significantly impact the electrochemical performance of metal-O2 batteries. In the study of CO2 contamination on metal-O2 batteries, it has been gradually found that CO2 can be utilized as the reactant gas alone; namely, metal-CO2 batteries can work. On the other hand, investigations on CO2 fixation are in focus due to the potential threat of CO2 on global climate change, especially for its steadily increasing concentration in the atmosphere. The exploitation of CO2 in energy storage systems represents an alternative approach towards clean recycling and utilization of CO2 . Here, the aim is to provide a timely summary of recent achievements in metal-CO2 batteries, and inspire new ideas for new energy storage systems. Moreover, critical issues associated with reaction mechanisms and potential directions for future studies are discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. CO2-Binding-Organic-Liquids-Enhanced CO2 Capture using Polarity-Swing-Assisted Regeneration

    SciTech Connect

    Zhang, Jian; Kutnyakov, Igor; Koech, Phillip K.; Zwoster, Andy; Howard, Chris; Zheng, Feng; Freeman, Charles J.; Heldebrant, David J.

    2013-01-01

    A new solvent-based CO2 capture process couples the unique attributes of non-aqueous, CO2-binding organic liquids (CO2BOLs) with the newly discovered polarity-swing-assisted regeneration (PSAR) process that is unique to switchable ionic liquids. Laboratory measurements with PSAR indicate the ability to achieve a regeneration effect at 75°C comparable to that at 120°C using thermal regeneration only. Initial measurements also indicate that the kinetic behavior of CO2 release is also improved with PSAR. Abstract cleared PNWD-SA-9743

  14. Measuring Nitrous Oxide Mass Transfer into Non-Aqueous CO2BOL CO2 Capture Solvents

    SciTech Connect

    Whyatt, Greg A.; Freeman, Charles J.; Zwoster, Andy; Heldebrant, David J.

    2016-03-28

    This paper investigates CO2 absorption behavior in CO2BOL solvents by decoupling the physical and chemical effects using N2O as a non-reactive mimic. Absorption measurements were performed using a wetted-wall contactor. Testing was performed using a “first generation” CO2 binding organic liquid (CO2BOL), comprised of an independent base and alcohol. Measurements were made with N2O at a lean (0.06 mol CO2/mol BOL) and rich (0.26 mol CO2/mol BOL) loading, each at three temperatures (35, 45 and 55 °C). Liquid-film mass transfer coefficients (kg') were calculated by subtracting the gas film resistance – determined from a correlation from literature – from the overall mass transfer measurement. The resulting kg' values for N2O in CO2BOLs were found to be higher than that of 5 M aqueous MEA under comparable conditions, which is supported by published measurements of Henry’s coefficients for N2O in various solvents. These results suggest that the physical solubility contribution for CO2 absorption in CO2BOLs is greater than that of aqueous amines, an effect that may pertain to other non-aqueous solvents.

  15. 2-μm high-power multiple-frequency single-mode Q-switched Ho:YLF laser for DIAL application

    NASA Astrophysics Data System (ADS)

    Gibert, Fabien; Edouart, Dimitri; Cénac, Claire; Le Mounier, Florian

    2014-09-01

    We report on the development and the demonstration of a two-wavelength single-frequency laser oscillator based on Ho:YLF crystal. This laser is especially suitable for application as a transmitter in differential absorption lidar (DIAL)/integrated path differential absorption (IPDA) measurements of atmospheric carbon dioxide (CO2) using the R30 CO2 absorption line at 2,050.967 nm. The oscillator consists in a fiber-coupled and free-space solid-state hybrid system and can be used in high-energy middle-rate or moderate-energy high-rate configurations. The latter produced On and Off sequentially single-frequency laser pulses with 13 mJ of energy at a repetition rate of 2 kHz and pulse duration of 42 ns. The pulse energy and frequency stabilities are specially documented in free-running, single-frequency and two-frequency seeding single-mode operations. Standard deviation is 7.7 % for pulse energy and 2 MHz for frequency stability for the two-wavelength seeding operation. Allan variance plot shows that frequency fluctuations are reduced below 70 kHz for 10 s of averaging which is suitable for accurate CO2 DIAL or IPDA measurements.

  16. Membraneless water filtration using CO2

    NASA Astrophysics Data System (ADS)

    Shin, Sangwoo; Shardt, Orest; Warren, Patrick; Stone, Howard

    2016-11-01

    Water purification technologies such as ultrafiltration and reverse osmosis utilize porous membranes to remove suspended particles and solutes. These membranes, however, cause many drawbacks such as a high pumping cost and a need for periodic replacement due to fouling. Here we show an alternative membraneless method for separating suspended particles by exposing the colloidal suspension to CO2. Dissolution of CO2 into the suspension creates solute gradients that drive phoretic motion of particles, or so-called diffusiophoresis. Due to the large diffusion potential built up by the dissociation of carbonic acid, colloidal particles move either away from or towards the gas-liquid interface depending on their surface charge. Our findings suggest a means to separate particles without membranes or filters, thus reducing operating and maintenance costs. Using the directed motion of particles induced by exposure to CO2, we demonstrate a scalable, continuous flow, membraneless particle filtration process that exhibits very low pressure drop and is essentially free from fouling.

  17. Membraneless water filtration using CO2

    NASA Astrophysics Data System (ADS)

    Shin, Sangwoo; Shardt, Orest; Warren, Patrick B.; Stone, Howard A.

    2017-05-01

    Water purification technologies such as microfiltration/ultrafiltration and reverse osmosis utilize porous membranes to remove suspended particles and solutes. These membranes, however, cause many drawbacks such as a high pumping cost and a need for periodic replacement due to fouling. Here we show an alternative membraneless method for separating suspended particles by exposing the colloidal suspension to CO2. Dissolution of CO2 into the suspension creates solute gradients that drive phoretic motion of particles. Due to the large diffusion potential generated by the dissociation of carbonic acid, colloidal particles move either away from or towards the gas-liquid interface depending on their surface charge. Using the directed motion of particles induced by exposure to CO2, we demonstrate a scalable, continuous flow, membraneless particle filtration process that exhibits low energy consumption, three orders of magnitude lower than conventional microfiltration/ultrafiltration processes, and is essentially free from fouling.

  18. Sequestration of CO2 by concrete carbonation.

    PubMed

    Galan, Isabel; Andrade, Carmen; Mora, Pedro; Sanjuan, Miguel A

    2010-04-15

    Carbonation of reinforced concrete is one of the causes of corrosion, but it is also a way to sequester CO2. The characteristics of the concrete cover should ensure alkaline protection for the steel bars but should also be able to combine CO2 to a certain depth. This work attempts to advance the knowledge of the carbon footprint of cement. As it is one of the most commonly used materials worldwide, it is very important to assess its impact on the environment. In order to quantify the capacity of cement based materials to combine CO2 by means of the reaction with hydrated phases to produce calcium carbonate, Thermogravimetry and the phenolphthalein indicator have been used to characterize several cement pastes and concretes exposed to different environments. The combined effect of the main variables involved in this process is discussed. The moisture content of the concrete seems to be the most influential parameter.

  19. CO2 sequestration in basalts: laboratory measurements

    NASA Astrophysics Data System (ADS)

    Otheim, L. T.; Adam, L.; van Wijk, K.; McLing, T. L.; Podgorney, R. K.

    2010-12-01

    Geologic sequestration of CO2 is proposed as the only promising large-scale method to help reduce CO2 gas emission by its capture at large point sources and subsequent long-term storage in deep geologic formations. Reliable and cost-effective monitoring will be important aspect of ensuring geological sequestration is a safe, effective, and acceptable method for CO2 emissions mitigation. Once CO2 injection starts, seismic methods can be used to monitor the migration of the carbon dioxide plume. To calibrate changes in rock properties from field observations, we propose to first analyze changes in elastic properties on basalt cores. Carbon dioxide sequestration in basalt rocks results in fluid substitution and mixing of CO2 with water and rock mineralizations. Carbon dioxide sequestration in mafic rocks creates reactions such as Mg2SiO 4 + CaMgSi2O 6 + 4CO2 = Mg 3Ca(CO 3) 4 + 3SiO2 whereby primary silicate minerals within the basalt react with carbonic acid laden water to creating secondary carbonate minerals and silicates. Using time-lapse laboratory scale experiments, such as laser generated ultrasonic wave propagation; it is possible to observe small changes in the physical properties of a rock. We will show velocity and modulus measurements on three basalt core samples for different saturation. The ultimate goal of the project is to track seismic changes due to fluid substitution and mineralization. The porosity of our basalts ranges from 8% to 12%, and the P-wave velocity increases by 20% to 40% from dry to water saturated conditions. Petrographic analysis (CT-scans, thin sections, XRF, XRf) will aid in the characterization of the mineral structure in these basalts and its correlation to seismic properties changes resulting from fluid substitution and mineralization.

  20. CO2 Orbital Trends in Comets

    NASA Astrophysics Data System (ADS)

    Kelley, Michael; Bodewits, Dennis; Feaga, Lori; Knight, Matthew; McKay, Adam; Snodgrass, Colin; Wooden, Diane

    2016-08-01

    Carbon dioxide is a primary volatile in comet nuclei, and potentially a major contributor to comet activity (i.e., the process of mass loss). However, CO2 cannot be observed directly from the ground, and past surveys of this molecule in comets were limited to space-borne snapshot observations. This situation limits our understanding of the behavior of CO2 in comets, and its role in driving comet mass loss. To address this deficiency, we were awarded a Cy11 Spitzer program designed to quantify the production rate of CO2 on >month-long timescales for 21 comets. We request an additional 269~hr in Cy13 to complete the Spitzer portion of our survey, and to add three more comets (46P/Wirtanen and 2 Target of Opportunity Oort cloud comets). Our survey is designed to probe the orbital trends of CO2 production in the comet population. We aim to: 1) examine the role of CO2 in the persistent post-perihelion activity observed in Jupiter-family comets; 2) measure the seasonal variations of CO2/H2O as a proxy for nucleus heterogeneity, when possible; 3) search for orbital trends sensitive to cumulative insolation as a proxy for nucleus layering; and 4) examine how Oort cloud comets evolve by comparing dynamically new and old targets. The final data set will allow us to investigate the effects of heating on the evolution of comets, if nucleus structures can be inferred through activity, and set the stage for JWST investigations into comet activity and composition.

  1. Local CO2-induced swelling of shales

    NASA Astrophysics Data System (ADS)

    Pluymakers, Anne; Dysthe, Dag Kristian

    2017-04-01

    In heterogeneous shale rocks, CO2 adsorbs more strongly to organic matter than to the other components. CO2-induced swelling of organic matter has been shown in coal, which is pure carbon. The heterogeneity of the shale matrix makes an interesting case study. Can local swelling through adsorption of CO2 to organic matter induce strain in the surrounding shale matrix? Can fractures close due to CO2-induced swelling of clays and organic matter? We have developed a new generation of microfluidic high pressure cells (up to 100 bar), which can be used to study flow and adsorption phenomena at the microscale in natural geo-materials. The devices contain one transparent side and a shale sample on the other side. The shale used is the Pomeranian shale, extracted from 4 km depth in Poland. This formation is a potential target of a combined CO2-storage and gas extraction project. To answer the first question, we place the pressure cell under a Veeco NT1100 Interferometer, operated in Vertical Scanning Interferometry mode and equipped with a Through Transmissive Media objective. This allows for observation of local swelling or organic matter with nanometer vertical resolution and micrometer lateral resolution. We expose the sample to CO2 atmospheres at different pressures. Comparison of the interferometry data and using SEM-EDS maps plus optical microscopy delivers local swelling maps where we can distinguish swelling of different mineralogies. Preliminary results indicate minor local swelling of organic matter, where the total amount is both time- and pressure-dependent.

  2. Forest carbon balance under elevated CO2.

    PubMed

    Hamilton, Jason G; DeLucia, Evan H; George, Kate; Naidu, Shawna L; Finzi, Adrien C; Schlesinger, William H

    2002-04-01

    Free-air CO2 enrichment (FACE) technology was used to expose a loblolly pine (Pinus taeda L.) forest to elevated atmospheric CO2 (ambient + 200 µl l(-1)). After 4 years, basal area of pine trees was 9.2% larger in elevated than in ambient CO2 plots. During the first 3 years the growth rate of pine was stimulated by ~26%. In the fourth year this stimulation declined to 23%. The average net ecosystem production (NEP) in the ambient plots was 428 gC m(-2) year(-1), indicating that the forest was a net sink for atmospheric CO2. Elevated atmospheric CO2 stimulated NEP by 41%. This increase was primarily an increase in plant biomass increment (57%), and secondarily increased accumulation of carbon in the forest floor (35%) and fine root increment (8%). Net primary production (NPP) was stimulated by 27%, driven primarily by increases in the growth rate of the pines. Total heterotrophic respiration (R h) increased by 165%, but total autotrophic respiration (R a) was unaffected. Gross primary production was increased by 18%. The largest uncertainties in the carbon budget remain in separating belowground heterotrophic (soil microbes) and autotrophic (root) respiration. If applied to temperate forests globally, the increase in NEP that we measured would fix less than 10% of the anthropogenic CO2 projected to be released into the atmosphere in the year 2050. This may represent an upper limit because rising global temperatures, land disturbance, and heterotrophic decomposition of woody tissues will ultimately cause an increased flux of carbon back to the atmosphere.

  3. Progress in coherent laser radar

    NASA Technical Reports Server (NTRS)

    Vaughan, J. M.

    1986-01-01

    Considerable progress with coherent laser radar has been made over the last few years, most notably perhaps in the available range of high performance devices and components and the confidence with which systems may now be taken into the field for prolonged periods of operation. Some of this increasing maturity was evident at the 3rd Topical Meeting on Coherent Laser Radar: Technology and Applications. Topics included in discussions were: mesoscale wind fields, nocturnal valley drainage and clear air down bursts; airborne Doppler lidar studies and comparison of ground and airborne wind measurement; wind measurement over the sea for comparison with satellite borne microwave sensors; transport of wake vortices at airfield; coherent DIAL methods; a newly assembled Nd-YAG coherent lidar system; backscatter profiles in the atmosphere and wavelength dependence over the 9 to 11 micrometer region; beam propagation; rock and soil classification with an airborne 4-laser system; technology of a global wind profiling system; target calibration; ranging and imaging with coherent pulsed and CW system; signal fluctuations and speckle. Some of these activities are briefly reviewed.

  4. Tunable diode laser absorption spectroscopy on 2.05 μm for the CO2 concentration measurement

    NASA Astrophysics Data System (ADS)

    Pranovich, Alina; Divoky, Martin; Prochazka, Ivan; Mocek, Tomas

    2015-05-01

    An experimental setup for the CO2 concentration measurement operating at 2.05 μm in pulsed mode and its characterization are presented. The system consists of a light source, which is a tunable laser diode operating in pulse mode. The initial radiation from the diode laser is divided into two parts: the first part of the beam is directed to a retro reflector, and the second part is used for diode output power monitoring. The receiving system consists of a focusing optic and a photodiode. The absorption is determined by comparing the intensities of the detected light on wavelengths absorbed and not absorbed by CO2 molecules. The prospects of the system change to a differential absorption lidar (DIAL) with a parametric generator as a light source that increases precision and range of generated wavelengths up to 10 μm are outlined.

  5. CO2 Acquisition Membrane (CAM) Project

    NASA Technical Reports Server (NTRS)

    Mason, L. W.; Way, J. D.; Vlasse, M.

    2001-01-01

    The CO2 Acquisition Membrane (CAM) project will develop, test, and analyze membrane materials for separation and purification of carbon dioxide (CO2) from mixtures of gases, such as those found in the Martian atmosphere. The CAM technology will enable passive separation of these gases, allow energy efficient acquisition and purification of these important resources, and lay the foundation for future unmanned sample return and human space missions. The CAM membranes are targeted toward In Situ Resource Utilization (ISRU) applications, such as In Situ Propellant Production (ISPP) and In Situ Consumables Production (ISCP).

  6. Do Tree Stems Recapture Respired CO2?

    NASA Astrophysics Data System (ADS)

    Hilman, B.; Angert, A.

    2016-12-01

    Tree stem respiration is an important, yet not well understood, component of the terrestrial carbon cycle. Predicting how trees as whole organisms respond to changes in climate and atmospheric CO2 requires understanding of the variability in the fraction of assimilated carbon allocated to respiration, versus the allocation to growth, damage repair, and to rhizosphere symbionts. Here we used the ratio of CO2 efflux/O2 influx (Apparent Respiratory Quotient, ARQ) to study stem respiration. The ARQ in trees stems is predicted to be 1.0, as a result of carbohydrates metabolism. Lower than 1.0 ARQ values may indicate a local assimilation of respired CO2, or dissolution and transport of CO2 in the xylem stream. We measured stems ARQ in 16 tree species at tropical, Mediterranean and temperate ecosystems using stem chambers and in-vitro incubations. The CO2 and O2 were measured by a system we developed, which is based on an IRGA and a Fuel-cell O2 analyzer (Hilman and Angert 2016). We found typical values of ARQ in the range of 0.4-0.8. Since incubations of detach stem tissues yielded similar ARQ values, and since the influence of natural variations in the transpiration stream on ARQ was found to be small, we conclude that the removal of the respired CO2 is not via dissolution in the xylem stream. Using 13C labeling, dark fixation of stem tissues was detected, which is most probably phosphoenolpyruvate carboxylase (PEPC) mediated. Hence, we suggest that in-stem dark fixation of respired CO2 to organic acids (e.g. malate) affects the outgoing efflux. Further research should determine if these organic acids are transported to the canopy, stored in the stem, or transported to the roots to serve as exudates. Hilman B, Angert A (2016) Measuring the ratio of CO2 efflux to O2 influx in tree stem respiration. Tree Physiol 2016, doi: 10.1093/treephys/tpw057

  7. Leak Path Development in CO2 Wells

    NASA Astrophysics Data System (ADS)

    Torsater, M.; Todorovic, J.; Opedal, N.; Lavrov, A.

    2014-12-01

    Wells have in numerous scientific works been denoted the "weak link" of safe and cost-efficient CO2 Capture and Storage (CCS). Whether they are active or abandoned, all wells are man-made intrusions into the storage reservoir with sealing abilities depending on degradable materials like steel and cement. If dense CO2 is allowed to expand (e.g. due to leakage) it will cool down its surroundings and cause strong thermal and mechanical loading on the wellbore. In addition, CO2 reacts chemically with rock, cement and steel. To ensure long-term underground containment, it is therefore necessary to study how, why, where and when leakage occurs along CO2wells. If cement bonding to rock or casing is poor, leak paths can form already during drilling and completion of the well. In the present work, we have mapped the bonding quality of cement-rock and cement-steel interfaces - and measured their resistance towards CO2 flow. This involved a large experimental matrix including different rocks, steels, cement types and well fluids. The bonding qualities were measured on composite cores using micro computed tomography (µ-CT), and CO2 was flooded through the samples to determine leakage rates. These were further compared to numerical simulations of leakage through the digitalized µ-CT core data, and CO2chemical interactions with the materials were mapped using electron microscopy. We also present a new laboratory set-up for measuring how well integrity is affected by downhole temperature variations - and we showcase some initial results. Our work concludes that leak path development in CO2 wells depends critically on the drilling fluids and presflushes/spacers chosen already during drilling and completion of a well. Fluid films residing on rock and casing surfaces strongly degrade the quality of cement bonding. The operation of the well is also important, as even slight thermal cycling (between 10°C and 95°C on casing) leads to significant de-bonding of the annular cement.

  8. CO2 laser cutting of natural granite

    NASA Astrophysics Data System (ADS)

    Riveiro, A.; Mejías, A.; Soto, R.; Quintero, F.; del Val, J.; Boutinguiza, M.; Lusquiños, F.; Pardo, J.; Pou, J.

    2016-01-01

    Commercial black granite boards (trade name: "Zimbabwe black granite") 10 mm thick, were successfully cut by a 3.5 kW CO2 laser source. Cutting quality, in terms of kerf width and roughness of the cut wall, was assessed by means of statistically planned experiments. No chemical modification of the material in the cutting walls was detected by the laser beam action. Costs associated to the process were calculated, and the main factors affecting them were identified. Results reported here demonstrate that cutting granite boards could be a new application of CO2 laser cutting machines provided a supersonic nozzle is used.

  9. 10 MW Supercritical CO2 Turbine Test

    SciTech Connect

    Turchi, Craig

    2014-01-29

    The Supercritical CO2 Turbine Test project was to demonstrate the inherent efficiencies of a supercritical carbon dioxide (s-CO2) power turbine and associated turbomachinery under conditions and at a scale relevant to commercial concentrating solar power (CSP) projects, thereby accelerating the commercial deployment of this new power generation technology. The project involved eight partnering organizations: NREL, Sandia National Laboratories, Echogen Power Systems, Abengoa Solar, University of Wisconsin at Madison, Electric Power Research Institute, Barber-Nichols, and the CSP Program of the U.S. Department of Energy. The multi-year project planned to design, fabricate, and validate an s-CO2 power turbine of nominally 10 MWe that is capable of operation at up to 700°C and operates in a dry-cooled test loop. The project plan consisted of three phases: (1) system design and modeling, (2) fabrication, and (3) testing. The major accomplishments of Phase 1 included: Design of a multistage, axial-flow, s-CO2 power turbine; Design modifications to an existing turbocompressor to provide s-CO2 flow for the test system; Updated equipment and installation costs for the turbomachinery and associated support infrastructure; Development of simulation tools for the test loop itself and for more efficient cycle designs that are of greater commercial interest; Simulation of s-CO2 power cycle integration into molten-nitrate-salt CSP systems indicating a cost benefit of up to 8% in levelized cost of energy; Identification of recuperator cost as a key economic parameter; Corrosion data for multiple alloys at temperatures up to 650ºC in high-pressure CO2 and recommendations for materials-of-construction; and Revised test plan and preliminary operating conditions based on the ongoing tests of related equipment. Phase 1 established that the cost of the facility needed to test the power turbine at its full power and temperature would exceed the planned funding for Phases 2 and 3. Late

  10. Geophysical monitoring of near surface CO2 injection at Svelvik - Learnings from the CO2FieldLab experiments.

    NASA Astrophysics Data System (ADS)

    Querendez, Etor; Romdhane, Anouar; Jordan, Michael; Eliasson, Peder; Grimstad, Alv-Arne

    2014-05-01

    A CO2 migration field laboratory for testing monitoring methods and tools has been established in the glaciofluvial-glaciomarine Holocene deposits of the Svelvik ridge, near Oslo (Norway). At the site, feasibility, sensitivity, acquisition geometry and usefulness of various surface and subsurface monitoring tools are investigated during controlled CO2 injection experiments. In a first stage, a shallow CO2 injection experiment was conducted in September 2011. Approximately 1700 kg of CO2 was injected at 18 m depth below surface in an unconsolidated sand formation. The objectives of this experiment were to (i) detect and, where possible, quantify migrated CO2 concentrations at the surface and very shallow subsurface, (ii) evaluate the sensitivity of the monitoring tools and (iii) study the impact of the vadose zone on observed measurements. Results showed that all deployed monitoring tools (for surface and near-surface gas monitoring, subsurface water monitoring and subsurface geophysical monitoring) where able to detect the presence of CO2 even though the CO2 plume did not migrate vertically as expected in what was thought to be an homogeneous unconsolidated sand structure. The upper part of the site revealed to be more heterogeneous than expected, mainly due to the highly variable lamination and channelling of the morainic sediments and to the presence of pebble and cobble beds sporadically showing throughout the deposits. Building on the learnings from the 18m depth injection experiment, a second experiment is being planned for a deeper injection, at a depth of 65m. Re-processing of the appraisal 2D multi-channel seismic with state-of-the-art processing techniques, like Linear Radon coherent and random noise attenuation and Full Waveform Inversion followed by pre-stack depth migration, corroborate the presence of heterogeneities at the near surface. Based on the re-interpreted seismic sections, a more realistic 3D geomodel, where the complex topography of the site

  11. Winter crop CO2 uptake inferred from CONTRAIL CO2 measurements over Delhi, India

    NASA Astrophysics Data System (ADS)

    Umezawa, T.; Niwa, Y.; Sawa, Y.; Machida, T.; Matsueda, H.

    2016-12-01

    CONTRAIL is an ongoing project that measures atmospheric trace gases onboard aircraft of Japan Airlines. Atmospheric CO2 concentration is analyzed using Continuous CO2 Measuring Equipment (CME) during intercontinental flights. Since 2005, we have obtained >7 millions of data points of CO2 concentration along level-flight and ascent/descent tracks of >12 thousands flights with extensive coverage of the Asia-Pacific region. In this study, we analyze 787 vertical profiles of CO2 over Delhi, India. The surrounding area is mainly covered by irrigated croplands with patchy urban areas. We observed a general increase of CO2 toward the ground in the boundary layer throughout December-April due to urban CO2 emissions from the Delhi metropolitan area. In January-March, however, we frequently observed sharp decreases of CO2 below 2 km, indicating the existence of local CO2 sinks in this season. We calculated enhancement/depletion of CO2 amount in the boundary layer, and found clear depletion in February-March, coincident with the growing season of the winter crops (mainly wheat) in the region. It is also inferred that the crop uptake may exceed in magnitude the urban anthropogenic emissions from the Delhi area, indicating significance of agricultural CO2 fluxes in the regional carbon budget. Due to the winter crop uptake, CO2 concentration over Delhi shows no increasing/decreasing temporal trends during January-March when that at baseline stations at similar latitudes in the northern hemisphere increases steadily. This suggests that the CONTRAIL measurements capture local to regional flux signals that are not well resolved by the existing observation network.

  12. Crystallization of CO2 ice and the absence of amorphous CO2 ice in space.

    PubMed

    Escribano, Rafael M; Muñoz Caro, Guillermo M; Cruz-Diaz, Gustavo A; Rodríguez-Lazcano, Yamilet; Maté, Belén

    2013-08-06

    Carbon dioxide (CO2) is one of the most relevant and abundant species in astrophysical and atmospheric media. In particular, CO2 ice is present in several solar system bodies, as well as in interstellar and circumstellar ice mantles. The amount of CO2 in ice mantles and the presence of pure CO2 ice are significant indicators of the temperature history of dust in protostars. It is therefore important to know if CO2 is mixed with other molecules in the ice matrix or segregated and whether it is present in an amorphous or crystalline form. We apply a multidisciplinary approach involving IR spectroscopy in the laboratory, theoretical modeling of solid structures, and comparison with astronomical observations. We generate an unprecedented highly amorphous CO2 ice and study its crystallization both by thermal annealing and by slow accumulation of monolayers from the gas phase under an ultrahigh vacuum. Structural changes are followed by IR spectroscopy. We also devise theoretical models to reproduce different CO2 ice structures. We detect a preferential in-plane orientation of some vibrational modes of crystalline CO2. We identify the IR features of amorphous CO2 ice, and, in particular, we provide a theoretical explanation for a band at 2,328 cm(-1) that dominates the spectrum of the amorphous phase and disappears when the crystallization is complete. Our results allow us to rule out the presence of pure and amorphous CO2 ice in space based on the observations available so far, supporting our current view of the evolution of CO2 ice.

  13. Crystallization of CO2 ice and the absence of amorphous CO2 ice in space

    PubMed Central

    Escribano, Rafael M.; Muñoz Caro, Guillermo M.; Cruz-Diaz, Gustavo A.; Rodríguez-Lazcano, Yamilet; Maté, Belén

    2013-01-01

    Carbon dioxide (CO2) is one of the most relevant and abundant species in astrophysical and atmospheric media. In particular, CO2 ice is present in several solar system bodies, as well as in interstellar and circumstellar ice mantles. The amount of CO2 in ice mantles and the presence of pure CO2 ice are significant indicators of the temperature history of dust in protostars. It is therefore important to know if CO2 is mixed with other molecules in the ice matrix or segregated and whether it is present in an amorphous or crystalline form. We apply a multidisciplinary approach involving IR spectroscopy in the laboratory, theoretical modeling of solid structures, and comparison with astronomical observations. We generate an unprecedented highly amorphous CO2 ice and study its crystallization both by thermal annealing and by slow accumulation of monolayers from the gas phase under an ultrahigh vacuum. Structural changes are followed by IR spectroscopy. We also devise theoretical models to reproduce different CO2 ice structures. We detect a preferential in-plane orientation of some vibrational modes of crystalline CO2. We identify the IR features of amorphous CO2 ice, and, in particular, we provide a theoretical explanation for a band at 2,328 cm−1 that dominates the spectrum of the amorphous phase and disappears when the crystallization is complete. Our results allow us to rule out the presence of pure and amorphous CO2 ice in space based on the observations available so far, supporting our current view of the evolution of CO2 ice. PMID:23858474

  14. Sustained effects of atmospheric [CO2] and nitrogen availability on forest soil CO2 efflux

    Treesearch

    A. Christopher Oishi; Sari Palmroth; Kurt H. Johnsen; Heather R. McCarthy; Ram. Oren

    2014-01-01

    Soil CO2 efflux (Fsoil) is the largest source of carbon from forests and reflects primary productivity as well as how carbon is allocated within forest ecosystems. Through early stages of stand development, both elevated [CO2] and availability of soil nitrogen (N; sum of mineralization, deposition, and fixation) have been shown to increase gross primary productivity,...

  15. Atmospheric CO2 enrichment and grassland productivity: Scaling CO2 effects through the plant community

    USDA-ARS?s Scientific Manuscript database

    Ecosystem responses to atmospheric CO2 enrichment, as to other climate change drivers, depend on plant community responses to CO2 (community response) and feedbacks from community change on ecosystem processes (community effect). We used data from two multi-year experiments in central Texas, USA to...

  16. Bosch CO2 Reduction System Development

    NASA Technical Reports Server (NTRS)

    Holmes, R. F.; King, C. D.; Keller, E. E.

    1976-01-01

    Development of a Bosch process CO2 reduction unit was continued, and, by means of hardware modifications, the performance was substantially improved. Benefits of the hardware upgrading were demonstrated by extensive unit operation and data acquisition in the laboratory. This work was accomplished on a cold seal configuration of the Bosch unit.

  17. 76 FR 15249 - Deferral for CO2

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-21

    ... deforestation. 2. Treatment of Biogenic CO 2 Emissions in the U.S. GHG Inventory National-level GHG inventories... solicited comment on the benefits and limitations of this proposed metric. \\15\\ U.S. EPA, ``Inventory of U.S...

  18. CO2 laser used in cosmetology

    NASA Astrophysics Data System (ADS)

    Su, Chenglie

    1993-03-01

    Cases of various kinds of warts, nevi, papillomas, skin angiomas, ephilises, skin vegetation, scars and brandy noses were vaporized and solidified with a 2.5 - 8 W low power CO2 laser with an overall satisfaction rate up to 99.8% and the satisfaction rate for one time 92%.

  19. Ocean acidification: the other CO2 problem.

    PubMed

    Doney, Scott C; Fabry, Victoria J; Feely, Richard A; Kleypas, Joan A

    2009-01-01

    Rising atmospheric carbon dioxide (CO2), primarily from human fossil fuel combustion, reduces ocean pH and causes wholesale shifts in seawater carbonate chemistry. The process of ocean acidification is well documented in field data, and the rate will accelerate over this century unless future CO2 emissions are curbed dramatically. Acidification alters seawater chemical speciation and biogeochemical cycles of many elements and compounds. One well-known effect is the lowering of calcium carbonate saturation states, which impacts shell-forming marine organisms from plankton to benthic molluscs, echinoderms, and corals. Many calcifying species exhibit reduced calcification and growth rates in laboratory experiments under high-CO2 conditions. Ocean acidification also causes an increase in carbon fixation rates in some photosynthetic organisms (both calcifying and noncalcifying). The potential for marine organisms to adapt to increasing CO2 and broader implications for ocean ecosystems are not well known; both are high priorities for future research. Although ocean pH has varied in the geological past, paleo-events may be only imperfect analogs to current conditions.

  20. A validation study on CO2 chemistry

    NASA Astrophysics Data System (ADS)

    Koelman, Peter; Heijkers, Stijn; Tadayon Musavi, Samaneh; Graef, Wouter; Bogaerts, Annemie; Dijk, Van, Jan; Elementary Processes in Gas Discharges Team; Plasmant Team

    2016-09-01

    The demand for renewable energy has increased the popularity of various energy sources, such as solar and wind energy. These sources are intermittent by nature, which typically does not match the demand of energy. Therefore, storage of energy is needed. Current tools for this are, however, costly, slow, and inefficient. Storing energy by the formation of valuable fuels from CO2 is potentially an improvement. By plasma assisted CO2 dissociation CO is produced. In subsequent steps the CO is transformed in valuable fuels. An extensive CO2 microwave plasma chemistry is studied, with special attention to the vibrational modes, which provide a pathway for the dissociation. To that end we developed a global model, which is only time resolved and needs less computational time than spatially resolved models. We present the results from a verification study of the CO2 chemistry. This is done by verification of input data, and by comparison of results obtained by two independent models: ZDPlaskin and PLASIMO's Global Model. We also present results from a sensitivity study of the input data.

  1. Agriculture waste and rising CO2

    USDA-ARS?s Scientific Manuscript database

    Currently, there are many uncertainties concerning agriculture’s role in global environmental change including the effects of rising atmospheric CO2 concentration. A viable and stable world food supply depends on productive agricultural systems, but environmental concerns within agriculture have to...

  2. 76 FR 43489 - Deferral for CO2

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-20

    ..., and wood pellet fuel manufacturing. 322 Pulp and paper manufacturing. Municipal solid waste 562213..., however, EPA also received information supporting the position that biogenic CO 2 should not be excluded... certain types of biomass can be part of the national strategy to reduce dependence on fossil fuels...

  3. Stereotactic CO2 laser therapy for hydrocephalus

    NASA Astrophysics Data System (ADS)

    Kozodoy-Pins, Rebecca L.; Harrington, James A.; Zazanis, George A.; Nosko, Michael G.; Lehman, Richard M.

    1994-05-01

    A new fiber-optic delivery system for CO2 radiation has been used to successfully treat non-communicating hydrocephalus. This system consists of a hollow sapphire waveguide employed in the lumen of a stereotactically-guided neuroendoscope. CO2 gas flows through the bore of the hollow waveguide, creating a path for the laser beam through the cerebrospinal fluid (CSF). This delivery system has the advantages of both visualization and guided CO2 laser radiation without the same 4.3 mm diameter scope. Several patients with hydrocephalus were treated with this new system. The laser was used to create a passage in the floor of the ventricle to allow the flow of CSF from the ventricles to the sub-arachnoid space. Initial postoperative results demonstrated a relief of the clinical symptoms. Long-term results will indicate if this type of therapy will be superior to the use of implanted silicone shunts. Since CO2 laser radiation at 10.6 micrometers is strongly absorbed by the water in tissue and CSF, damage to tissue surrounding the lesion with each laser pulse is limited. The accuracy and safety of this technique may prove it to be an advantageous therapy for obstructive hydrocephalus.

  4. Porous Hexacyanometalates for CO2 capture applications

    SciTech Connect

    Motkuri, Radha K.; Thallapally, Praveen K.; McGrail, B. Peter

    2013-07-30

    Prussian blue analogues of M3[Fe(CN)6]2 x H2O (where M=Fe, Mn and Ni) were synthesized, characterized and tested for their gas sorption capabilities. The sorption studies reveal that, these Prussian blue materials preferentially sorb CO2 over N2 and CH4 at low pressure (1bar).

  5. Transdermal CO2 application in chronic wounds.

    PubMed

    Wollina, U; Heinig, Birgit; Uhlemann, Christine

    2004-06-01

    Chronic wounds are a challenge to treatment. In this retrospective study, the effect of transdermal CO2 application on wound healing in chronic ulcers was investigated and compared to the effect of CO2 on acute surgical wounds. Eighty-six patients (52 females and 34 males) with chronic wounds of different origin except arterial occlusive disease were included. In addition, 17 patients (5 females, 12 males) with wide excision wounds after surgical therapy of acne inversa were considered. The indication for CO2 application was a wound at risk for infection. Treatment was performed with a Carboflow device once daily for 30 to 60 minutes. There was clinical evidence of improvement of granulation and reduction of discharge and malodor within 1 week of treatment in both chronic and acute wounds. Only 9 patients, all diabetics, needed an additional systemic antibiosis. The treatment was well tolerated. No adverse effects have been noted. Transdermal CO2 application is a useful method to reduce the risk of infection and improve wound healing in both chronic and certain acute wounds. Systematic prospective trials are needed.

  6. The ATLAS IBL CO2 cooling system

    NASA Astrophysics Data System (ADS)

    Verlaat, B.; Ostrega, M.; Zwalinski, L.; Bortolin, C.; Vogt, S.; Godlewski, J.; Crespo-Lopez, O.; Van Overbeek, M.; Blaszcyk, T.

    2017-02-01

    The ATLAS Pixel detector has been equipped with an extra pixel layer in the space obtained by a smaller radius beam pipe. This new pixel layer called the Insertable B-Layer (IBL) was installed in 2014 and is operational in the current ATLAS data taking. The IBL detector is cooled with evaporative CO2 and is the first of its kind in ATLAS. The ATLAS IBL CO2 cooling system is designed for lower temperature operation (< ‑35oC) than the previous developed CO2 cooling systems in High Energy Physics experiments. The cold temperatures are required to protect the pixel sensors for the expected high radiation dose received at an integrated luminosity of 550 fb1. This paper describes the design, development, construction and commissioning of the IBL CO2 cooling system. It describes the challenges overcome and the important lessons learned for the development of future systems which are now under design for the Phase-II upgrade detectors.

  7. Blackbody-pumped CO2 laser experiment

    NASA Astrophysics Data System (ADS)

    Christiansen, W. H.; Insuik, R. J.

    1983-07-01

    Thermal radiation from a high temperature oven was used as an optical pump to achieve lasing from CO2 mixtures. Laser output as a function of blackbody temperature and gas conditions is described. This achievement represents the first blackbody cavity pumped laser and has potential for solar pumping. Previously announced in STAR as N83-10420

  8. CO2 dispersion modelling over Paris region within the CO2-MEGAPARIS project

    NASA Astrophysics Data System (ADS)

    Lac, C.; Donnelly, R. P.; Masson, V.; Pal, S.; Donier, S.; Queguiner, S.; Tanguy, G.; Ammoura, L.; Xueref-Remy, I.

    2012-10-01

    Accurate simulation of the spatial and temporal variability of tracer mixing ratios over urban areas is challenging, but essential in order to utilize CO2 measurements in an atmospheric inverse framework to better estimate regional CO2 fluxes. This study investigates the ability of a high-resolution model to simulate meteorological and CO2 fields around Paris agglomeration, during the March field campaign of the CO2-MEGAPARIS project. The mesoscale atmospheric model Meso-NH, running at 2 km horizontal resolution, is coupled with the Town-Energy Balance (TEB) urban canopy scheme and with the Interactions between Soil, Biosphere and Atmosphere CO2-reactive (ISBA-A-gs) surface scheme, allowing a full interaction of CO2 between the surface and the atmosphere. Statistical scores show a good representation of the Urban Heat Island (UHI) and urban-rural contrasts. Boundary layer heights (BLH) at urban, sub-urban and rural sites are well captured, especially the onset time of the BLH increase and its growth rate in the morning, that are essential for tall tower CO2 observatories. Only nocturnal BLH at sub-urban sites are slightly underestimated a few nights, with a bias less than 50 m. At Eiffel tower, the observed spikes of CO2 maxima occur every morning exactly at the time at which the Atmospheric Boundary Layer (ABL) growth reaches the measurement height. The timing of the CO2 cycle is well captured by the model, with only small biases on CO2 concentrations, mainly linked to the misrepresentation of anthropogenic emissions, as the Eiffel site is at the heart of trafic emission sources. At sub-urban ground stations, CO2 measurements exhibit maxima at the beginning and at the end of each night, when the ABL is fully contracted, with a very strong spatio-temporal variability. The CO2 cycle at these sites is generally well reproduced by the model, even if some biases on the nocturnal maxima appear in the Paris plume parly due to small errors on the vertical transport, or in

  9. Development of Novel CO2 Adsorbents for Capture of CO2 from Flue Gas

    SciTech Connect

    Fauth, D.J.; Filburn, T.P.; Gray, M.L.; Hedges, S.W.; Hoffman, J.; Pennline, H.W.; Filburn, T.

    2007-06-01

    Capturing CO2 emissions generated from fossil fuel-based power plants has received widespread attention and is considered a vital course of action for CO2 emission abatement. Efforts are underway at the Department of Energy’s National Energy Technology Laboratory to develop viable energy technologies enabling the CO2 capture from large stationary point sources. Solid, immobilized amine sorbents (IAS) formulated by impregnation of liquid amines within porous substrates are reactive towards CO2 and offer an alternative means for cyclic capture of CO2 eliminating, to some degree, inadequacies related to chemical absorption by aqueous alkanolamine solutions. This paper describes synthesis, characterization, and CO2 adsorption properties for IAS materials previously tested to bind and release CO2 and water vapor in a closed loop life support system. Tetraethylenepentamine (TEPA), acrylonitrile-modified tetraethylenepentamine (TEPAN), and a single formulation consisting of TEPAN and N, N’-bis(2-hydroxyethyl)ethylenediamine (BED) were individually supported on a poly (methyl methacrylate) (PMMA) substrate and examined. CO2 adsorption profiles leading to reversible CO2 adsorption capacities were obtained using thermogravimetry. Under 10% CO2 in nitrogen at 25°C and 1 atm, TEPA supported on PMMA over 60 minutes adsorbed ~3.2 mmol/g{sorbent} whereas, TEPAN supported on PMMA along with TEPAN and BED supported on PMMA adsorbed ~1.7 mmol/g{sorbent} and ~2.3 mmol/g{sorbent} respectively. Cyclic experiments with a 1:1 weight ratio of TEPAN and BED supported on poly (methyl methacrylate) beads utilizing a fixed-bed flow system with 9% CO2, 3.5% O2, nitrogen balance with trace gas constituents were studied. CO2 adsorption capacity was ~ 3 mmols CO2/g{sorbent} at 40°C and 1.4 atm. No beneficial effect on IAS performance was found using a moisture-laden flue gas mixture. Tests with 750 ppmv NO in a humidified gas stream revealed negligible NO sorption onto the IAS. A high SO2

  10. CO2 adsorption isotherm on clay minerals and the CO2 accessibility into the clay interlayer

    NASA Astrophysics Data System (ADS)

    Gensterblum, Yves; Bertier, Pieter; Busch, Andreas; Rother, Gernot; Krooß, Bernhard

    2013-04-01

    Large-scale CO2 storage in porous rock formations at 1-3 km depth is seen as a global warming mitigation strategy. In this process, CO2 is separated from the flue gas of coal or gas power plants, compressed, and pumped into porous subsurface reservoirs with overlying caprocks (seals). Good seals are mechanically and chemically stable caprocks with low porosity and permeability. They prevent leakage of buoyant CO2 from the reservoir. Caprocks are generally comprised of thick layers of shale, and thus mainly consist of clay minerals. These clays can be affected by CO2-induced processes, such as swelling or dissolution. The interactions of CO2 with clay minerals in shales are at present poorly understood. Sorption measurements in combination scattering techniques could provide fundamental insight into the mechanisms governing CO2-clay interaction. Volumetric sorption techniques have assessed the sorption of supercritical CO2 onto coal (Gensterblum et al., 2010; Gensterblum et al., 2009), porous silica (Rother et al., 2012a) and clays as a means of exploring the potential of large-scale storage of anthropogenic CO2 in geological reservoirs (Busch et al., 2008). On different clay minerals and shales, positive values of excess sorption were measured at gas pressures up to 6 MPa, where the interfacial fluid is assumed to be denser than the bulk fluid. However, zero and negative values were obtained at higher densities, which suggests the adsorbed fluid becomes equal to and eventually less dense than the corresponding bulk fluid, or that the clay minerals expand on CO2 charging. Using a combination of neutron diffraction and excess sorption measurements, we recently deduced the interlayer density of scCO2 in Na-montmorillonite clay in its single-layer hydration state (Rother et al., 2012b), and confirmed its low density, as well as the expansion of the basal spacings. We performed neutron diffraction experiments at the FRMII diffractometer on smectite, kaolinite and illite

  11. Flash scanning the CO2 laser: a revival of the CO2 laser in plastic surgery

    NASA Astrophysics Data System (ADS)

    Lach, Elliot

    1994-09-01

    The CO2 laser has broad clinical application yet also presents a number of practical disadvantages. These drawbacks have limited the success and utilization of this laser in plastic surgery. Flashscanner technology has recently been used for char-free CO2 laser surgery of the oropharynx, the external female genital tract, and perirectal mucosa. A commercially available optomechanical flashscanner unit `Swiftlase,' was adapted to a CO2 laser and used for treatment in numerous plastic surgical applications. Conditions and situations that were treated in this study included generalized neurofibromatosis, tuberous sclerosis, rhinophyma, viral warts, breast reconstruction, and deepithelialization prior to microsurgery or local flap transfer and/or skin graft placement. There were no significant wound healing complications. Some patients previously sustained undue scarring from conventional CO2 laser surgery. Conservative, primarily ablative CO2 laser surgery with the Swiftlase has usefulness for treatment of patients in plastic surgery including those that were previously unsuccessfully treated.

  12. Extraction of lipids from microalgae using CO2-expanded methanol and liquid CO2.

    PubMed

    Paudel, Ashok; Jessop, Michael J; Stubbins, Spencer H; Champagne, Pascale; Jessop, Philip G

    2015-05-01

    The use of CO2-expanded methanol (cxMeOH) and liquid carbon dioxide (lCO2) is proposed to extract lipids from Botryococcus braunii. When compressed CO2 dissolves in methanol, the solvent expands in volume, decreases in polarity and so increases in its selectivity for biodiesel desirable lipids. Solid phase extraction of the algal extract showed that the cxMeOH extracted 21 mg of biodiesel desirable lipids per mL of organic solvent compared to 3mg/mL using either neat methanol or chloroform/methanol mixture. The non-polar lCO2 showed a high affinity for non-polar lipids. Using lCO2, it is possible to extract up to 10% neutral lipids relative to the mass of dry algae. Unlike extractions using conventional solvents, these new methods require little to no volatile, flammable, or chlorinated organic solvents. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Sensitivity of simulated CO2 concentration to regridding of global fossil fuel CO2 emissions

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Gurney, K. R.; Rayner, P.; Liu, Y.; Asefi-Najafabady, S.

    2014-06-01

    Errors in the specification or utilization of fossil fuel CO2 emissions within carbon budget or atmospheric CO2 inverse studies can alias the estimation of biospheric and oceanic carbon exchange. A key component in the simulation of CO2 concentrations arising from fossil fuel emissions is the spatial distribution of the emission near coastlines. Finite grid resolution can give rise to mismatches between the emissions and simulated atmospheric dynamics which differ over land or water. We test these mismatches by examining simulated global atmospheric CO2 concentration driven by two different approaches to regridding fossil fuel CO2 emissions. The two approaches are: (1) a commonly-used method that allocates emissions to gridcells with no attempt to ensure dynamical consistency with atmospheric transport; (2) an improved method that reallocates emissions to gridcells to ensure dynamically consistent results. Results show large spatial and temporal differences in the simulated CO2 concentration when comparing these two approaches. The emissions difference ranges from -30.3 Tg C gridcell-1 yr-1 (-3.39 kg C m-2 yr-1) to +30.0 Tg C gridcell-1 yr-1 (+2.6 kg C m-2 yr-1) along coastal margins. Maximum simulated annual mean CO2 concentration differences at the surface exceed ±6 ppm at various locations and times. Examination of the current CO2 monitoring locations during the local afternoon, consistent with inversion modeling system sampling and measurement protocols, finds maximum hourly differences at 38 stations exceed ±0.10 ppm with individual station differences exceeding -32 ppm. The differences implied by not accounting for this dynamical consistency problem are largest at monitoring sites proximal to large coastal urban areas and point sources. These results suggest that studies comparing simulated to observed atmospheric CO2 concentration, such as atmospheric CO2 inversions, must take measures to correct for this potential problem and ensure flux and dynamical

  14. Sustained effects of atmospheric [CO2] and nitrogen availability on forest soil CO2 efflux.

    PubMed

    Oishi, A Christopher; Palmroth, Sari; Johnsen, Kurt H; McCarthy, Heather R; Oren, Ram

    2014-04-01

    Soil CO2 efflux (Fsoil ) is the largest source of carbon from forests and reflects primary productivity as well as how carbon is allocated within forest ecosystems. Through early stages of stand development, both elevated [CO2] and availability of soil nitrogen (N; sum of mineralization, deposition, and fixation) have been shown to increase gross primary productivity, but the long-term effects of these factors on Fsoil are less clear. Expanding on previous studies at the Duke Free-Air CO2 Enrichment (FACE) site, we quantified the effects of elevated [CO2] and N fertilization on Fsoil using daily measurements from automated chambers over 10 years. Consistent with previous results, compared to ambient unfertilized plots, annual Fsoil increased under elevated [CO2] (ca. 17%) and decreased with N (ca. 21%). N fertilization under elevated [CO2] reduced Fsoil to values similar to untreated plots. Over the study period, base respiration rates increased with leaf productivity, but declined after productivity saturated. Despite treatment-induced differences in aboveground biomass, soil temperature and water content were similar among treatments. Interannually, low soil water content decreased annual Fsoil from potential values - estimated based on temperature alone assuming nonlimiting soil water content - by ca. 0.7% per 1.0% reduction in relative extractable water. This effect was only slightly ameliorated by elevated [CO2]. Variability in soil N availability among plots accounted for the spatial variability in Fsoil , showing a decrease of ca. 114 g C m(-2) yr(-1) per 1 g m(-2) increase in soil N availability, with consistently higher Fsoil in elevated [CO2] plots ca. 127 g C per 100 ppm [CO2] over the +200 ppm enrichment. Altogether, reflecting increased belowground carbon partitioning in response to greater plant nutritional needs, the effects of elevated [CO2] and N fertilization on Fsoil in this stand are sustained beyond the early stages of stand development and

  15. Rapid CO2 permeation across biological membranes: implications for CO2 venting from tissue.

    PubMed

    Hulikova, Alzbeta; Swietach, Pawel

    2014-07-01

    The degree to which cell membranes are barriers to CO2 transport remains controversial. Proteins, such as aquaporins and Rh complex, have been proposed to facilitate CO2 transport, implying that the nonchannel component of membranes must have greatly reduced CO2 permeability. To determine whether membrane CO2 permeation is rate limiting for gas transport, the spread of CO2 across multicellular tissue growths (spheroids) was measured using intracellular pH as a spatial readout. Colorectal HCT116 cells have basal water and NH3 permeability, indicating the functional absence of aquaporins and gas channels. However, CO2 diffusivity in HCT116 spheroids was only 24 ± 4% lower than in pure water, which can be accounted for fully by volume exclusion due to proteins. Diffusivity was unaffected by blockers of aquaporins and Rh complex (Hg(2+), p-chloromercuribenzoic acid, and 4,4'-diisothiocyano-2,2'-stilbene-disulfonic acid) but decreased under hypertonic conditions (by addition of 300 mOsm mannitol), which increases intracellular protein crowding. Similar CO2 diffusivity was measured in spheroids of T47D breast cells (basal water permeability) and NHDF-Ad fibroblasts (aquaporin-facilitated water permeability). In contrast, diffusivity of NH3, a smaller but less lipophilic gas, was considerably slower than in pure water, as expected from rate-limiting membrane permeation. In conclusion, membranes, even in the functional absence of proposed gas channels, do not restrict CO2 venting from tissue growths.-Hulikova, A., Swietach, P. Rapid CO2 permeation across biological membranes: implications for CO2 venting from tissue.

  16. Vadose Zone Remediation of CO2 Leakage from Geologic CO2 Storage Sites

    SciTech Connect

    Zhang, Yingqi; Oldenburg, Curtis M.; Benson, Sally M.

    2004-03-03

    In the unlikely event that CO2 leakage from deep geologic CO2 sequestration sites reaches the vadose zone, remediation measures for removing the CO2 gas plume may have to be undertaken. Carbon dioxide leakage plumes are similar in many ways to volatile organic compound (VOC) vapor plumes, and the same remediation approaches are applicable. We present here numerical simulation results of passive and active remediation strategies for CO2 leakage plumes in the vadose zone. The starting time for the remediation scenarios is assumed to be after a steady-state CO2 leakage plume is established in the vadose zone, and the source of this plume has been cut off. We consider first passive remediation, both with and without barometric pumping. Next, we consider active methods involving extraction wells in both vertical and horizontal configurations. To compare the effectiveness of the various remediation strategies, we define a half-life of the CO2 plume as a convenient measure of the CO2 removal rate. For CO2 removal by passive remediation approaches such as barometric pumping, thicker vadose zones generally require longer remediation times. However, for the case of a thin vadose zone where a significant fraction of the CO2 plume mass resides within the high liquid saturation region near the water table, the half-life of the CO2 plume without barometric pumping is longer than for somewhat thicker vadose zones. As for active strategies, results show that a combination of horizontal and vertical wells is the most effective among the strategies investigated, as the performance of commonly used multiple vertical wells was not investigated.

  17. Isolation of microorganisms from CO2 sequestration sites through enrichments under high pCO2

    NASA Astrophysics Data System (ADS)

    Peet, K. C.; Freedman, A. J.; Boreham, C.; Thompson, J. R.

    2012-12-01

    Carbon Capture and Storage (CCS) in geologic formations has the potential to reduce greenhouse gas emissions from fossil fuel processing and combustion. However, little is known about the effects that CO2 may have on biological activity in deep earth environments. To understand microorganisms associated with these environments, we have developed a simple high-pressure enrichment methodology to cultivate organisms capable of growth under supercritical CO2 (scCO2). Growth media targeting different subsurface functional metabolic groups is added to sterilized 316 stainless steel tubing sealed with quarter turn plug valves values and pressurized to 120-136 atm using a helium-padded CO2 tank, followed by incubation at 37 °C to achieve the scCO2 state. Repeated passages of crushed subsurface rock samples and growth media under supercritical CO2 headspaces are assessed for growth via microscopic enumeration. We have utilized this method to survey sandstone cores for microbes capable of growth under scCO2 from two different geologic sites targeted for carbon sequestration activities. Reproducible growth of microbial biomass under high pCO2 has been sustained from each site. Cell morphologies consist of primarily 1-2 μm rods and oval spores, with densities from 1E5-1E7 cells per ml of culture. We have purified and characterized a bacterial strain most closely related to Bacillus subterraneus (99% 16S rRNA identity) capable of growth under scCO2. Preliminary physiological characterization of this strain indicates it is a spore-forming facultative anaerobe able to grow in 0.5 to 50 ppt salinity. Genome sequencing and analysis currently in progress will help reveal genetic mechanisms of acclimation to high pCO2 conditions associated with geologic carbon sequestration.

  18. The Role of the CO2 Laser and Fractional CO2 Laser in Dermatology

    PubMed Central

    Omi, Tokuya; Numano, Kayoko

    2014-01-01

    Background: Tremendous advances have been made in the medical application of the laser in the past few decades. Many diseases in the dermatological field are now indications for laser treatment that qualify for reimbursement by many national health insurance systems. Among laser types, the carbon dioxide (CO2) laser remains an important system for the dermatologist. Rationale: The lasers used in photosurgery have wavelengths that differ according to their intended use and are of various types, but the CO2 laser is one of the most widely used lasers in the dermatology field. With its wavelength in the mid-infrared at 10,600 nm, CO2 laser energy is wellabsorbed in water. As skin contains a very high water percentage, this makes the CO2 laser ideal for precise, safe ablation with good hemostasis. In addition to its efficacy in ablating benign raised lesions, the CO2 laser has been reported to be effective in the field of esthetic dermatology in the revision of acne scars as well as in photorejuvenation. With the addition of fractionation of the beam of energy into myriad microbeams, the fractional CO2 laser has offered a bridge between the frankly full ablative indications and the nonablative skin rejuvenation systems of the 2000s in the rejuvenation of photoaged skin on and off the face. Conclusions: The CO2 laser remains an efficient, precise and safe system for the dermatologist. Technological advances in CO2 laser construction have meant smaller spot sizes and greater precision for laser surgery, and more flexibility in tip sizes and protocols for fractional CO2 laser treatment. The range of dermatological applications of the CO2 laser is expected to continue to increase in the future. PMID:24771971

  19. CO2 Orbital Trends in Comets

    NASA Astrophysics Data System (ADS)

    Kelley, Michael; Feaga, Lori; Bodewits, Dennis; McKay, Adam; Snodgrass, Colin; Wooden, Diane

    2014-12-01

    Spacecraft missions to comets return a treasure trove of details of their targets, e.g., the Rosetta mission to comet 67P/Churyumov-Gerasimenko, the Deep Impact experiment at comet 9P/Tempel 1, or even the flyby of C/2013 A1 (Siding Spring) at Mars. Yet, missions are rare, the diversity of comets is large, few comets are easily accessible, and comet flybys essentially return snapshots of their target nuclei. Thus, telescopic observations are necessary to place the mission data within the context of each comet's long-term behavior, and to further connect mission results to the comet population as a whole. We propose a large Cycle 11 project to study the long-term activity of past and potential future mission targets, and select bright Oort cloud comets to infer comet nucleus properties, which would otherwise require flyby missions. In the classical comet model, cometary mass loss is driven by the sublimation of water ice. However, recent discoveries suggest that the more volatile CO and CO2 ices are the likely drivers of some comet active regions. Surprisingly, CO2 drove most of the activity of comet Hartley 2 at only 1 AU from the Sun where vigorous water ice sublimation would be expected to dominate. Currently, little is known about the role of CO2 in comet activity because telluric absorptions prohibit monitoring from the ground. In our Cycle 11 project, we will study the CO2 activity of our targets through IRAC photometry. In conjunction with prior observations of CO2 and CO, as well as future data sets (JWST) and ongoing Earth-based projects led by members of our team, we will investigate both long-term activity trends in our target comets, with a particular goal to ascertain the connections between each comet's coma and nucleus.

  20. Raindrop Impact, Disaggregation & CO2 emissions

    NASA Astrophysics Data System (ADS)

    Gao, Xin; Wang, Rui; Hu, Yaxian; Guo, Shengli

    2017-04-01

    On the Chinese Loess Plateau, heave storms often occur from July to September, which happens to be fallow season. Without protections from crop coverage, soil surface is completely exposed to rainfalls, receives much more enhanced raindrop impact, thus potentially experience advanced disaggregation. After breaking into smaller fragments, and exposing those previously encapsulated soil organic carbon (SOC), soil surface is very likely to release additional CO2 emissions. However, the possible addition of CO2 emissions from fallow season on the Chinese Loess Plateau, and its potential contribution to local carbon balances, have not yet been systematically investigated. In order to compare the effects of raindrop impacts to CO2 emissions on bare soil during fallow season, two erosion plots (100 cm * 40 cm *35 cm) were set up. Both plots were filled with the loess soil. One plot was covered with two meshes (1 mm * 1mm)overlapping each other, to simulate crop coverage; the other plot was directly exposed to raindrops. Both plots were placed underneath simulated rainfalls (intensity of 90 mm h-1), for 5 min and 10 min. After 24 hours post rainfalls, soil moisture and CO2 emissions from both plots were measured every day for one week. Soil particle size distributions from surface soil were also determined to compare the changes of soil composition. Our results show that raindrop impacted soil in general released more CO2 emissions than the covered soil, and this pattern was more pronounced after experiencing longer period of rainfall events (20.6% more after 5 min; 48.3% more after 10 min). This agreed well with the increase of soil particles < 0.01 mm observed on the raindrop impacted soil surface.

  1. CO2 profile retrievals from TCCON spectra

    NASA Astrophysics Data System (ADS)

    Dohe, Susanne; Hase, Frank; Sepúlveda, Eliezer; García, Omaira; Wunch, Debra; Wennberg, Paul; Gómez-Peláez, Angel; Abshire, James B.; Wofsy, Steven C.; Schneider, Matthias; Blumenstock, Thomas

    2014-05-01

    The Total Carbon Column Observing Network (TCCON) is a global network of ground-based Fourier Transform Spectrometers recording direct solar spectra in the near-infrared spectral region. With stringent requirements on the instrumentation, data processing and calibration, accurate and precise column-averaged abundances of CO2, CH4, N2O, HF, CO, H2O, and HDO are retrieved being an essential contribution for the validation of satellite data (e.g. GOSAT, OCO-2) and carbon cycle research (Olsen and Randerson, 2004). However, the determined column-averaged dry air mole fraction (DMF) contains no information about the vertical CO2 profile, due to the use of a simple scaling retrieval within the common TCCON analysis, where the fitting algorithm GFIT (e.g. Yang et al., 2005) is used. In this presentation we will apply a different procedure for calculating trace gas abundances from the measured spectra, the fitting algorithm PROFFIT (Hase et. al., 2004) which has been shown to be in very good accordance with GFIT. PROFFIT additionally offers the ability to perform profile retrievals in which the pressure broadening effect of absorption lines is used to retrieve vertical gas profiles, being of great interest especially for the CO2 modelling community. A new analyzing procedure will be shown and retrieved vertical CO2 profiles of the TCCON sites Izaña (Tenerife, Canary Islands, Spain) and Lamont (Oklahoma, USA) will be presented and compared with simultaneously performed surface in-situ measurements and CO2 profiles from different aircraft campaigns. References: - Hase, F. et al., J.Q.S.R.T. 87, 25-52, 2004. - Olsen, S.C. and Randerson, J.T., J.G.Res., 109, D023012, 2004. - Yang, Z. et al., J.Q.S.R.T., 90, 309-321, 2005.

  2. Efficient 1.6 Micron Laser Source for Methane DIAL

    NASA Technical Reports Server (NTRS)

    Shuman, Timothy; Burnham, Ralph; Nehrir, Amin R.; Ismail, Syed; Hair, Johnathan W.

    2013-01-01

    Methane is a potent greenhouse gas and on a per molecule basis has a warming influence 72 times that of carbon dioxide over a 20 year horizon. Therefore, it is important to look at near term radiative effects due to methane to develop mitigation strategies to counteract global warming trends via ground and airborne based measurements systems. These systems require the development of a time-resolved DIAL capability using a narrow-line laser source allowing observation of atmospheric methane on local, regional and global scales. In this work, a demonstrated and efficient nonlinear conversion scheme meeting the performance requirements of a deployable methane DIAL system is presented. By combining a single frequency 1064 nm pump source and a seeded KTP OPO more than 5 mJ of 1.6 µm pulse energy is generated with conversion efficiencies in excess of 20%. Even without active cavity control instrument limited linewidths (50 pm) were achieved with an estimated spectral purity of 95%. Tunable operation over 400 pm (limited by the tuning range of the seed laser) was also demonstrated. This source demonstrated the critical needs for a methane DIAL system motivating additional development of the technology.

  3. Indoor radon and lung cancer in the radium dial workers

    SciTech Connect

    Neuberger, J.S.; Rundo, J.

    1996-12-31

    Internally deposited radium has long been known to have tumorigenic effects in the form of sarcomas of the bone and carcinomas of the paranasal sinuses and mastoid air cells. However, the radium dial workers were also exposed to radiation hazards other than that occurring from ingestion of the radium paint, viz., external gamma radiation and elevated concentrations of airborne radon. The uranium miners were also exposed to high concentrations of radon in the 1950s and later, and numerous cases of lung cancer have occurred in that population. However, unlike the atmosphere in the uranium mines, the air in the dial painting plants was probably rather clean and perhaps not much different from the air in many houses. In view of the current concern over the possibility of lung cancer fin the general population being caused by radon (progeny) in houses, it is important to examine the mortality due to this usually fatal disease in the dial workers and to attempt to relate it to their exposure to radon, to the extent that this is possible.

  4. Airborne UV DIAL Measurements of Ozone and Aerosols

    NASA Technical Reports Server (NTRS)

    Grant, William B.; Browell, Edward V.

    2000-01-01

    The NASA Langley Research Center's airborne UV Differential Absorption Lidar (DIAL) system measures vertical profiles of ozone and aerosols above and below the aircraft along its flight track. This system has been used in over 20 airborne field missions designed to study the troposphere and stratosphere since 1980. Four of these missions involved tropospheric measurement programs in the Pacific Ocean with two in the western North Pacific and two in the South Pacific. The UV DIAL system has been used in these missions to study such things as pollution outflow, long-range transport, and stratospheric intrusions; categorize the air masses encountered; and to guide the aircraft to altitudes where interesting features can be studied using the in situ instruments. This paper will highlight the findings with the UV DIAL system in the Pacific Ocean field programs and introduce the mission planned for the western North Pacific for February-April 2001. This will be an excellent opportunity for collaboration between the NASA airborne mission and those with ground-based War systems in Asia Pacific Rim countries to make a more complete determination of the transport of air from Asia to the western Pacific.

  5. Detection of CO2 leakage by the surface-soil CO2-concentration monitoring (SCM) system in a small scale CO2 release test

    NASA Astrophysics Data System (ADS)

    Chae, Gitak; Yu, Soonyoung; Sung, Ki-Sung; Choi, Byoung-Young; Park, Jinyoung; Han, Raehee; Kim, Jeong-Chan; Park, Kwon Gyu

    2015-04-01

    Monitoring of CO2 release through the ground surface is essential to testify the safety of CO2 storage projects. We conducted a feasibility study of the multi-channel surface-soil CO2-concentration monitoring (SCM) system as a soil CO2 monitoring tool with a small scale injection. In the system, chambers are attached onto the ground surface, and NDIR sensors installed in each chamber detect CO2 in soil gas released through the soil surface. Before injection, the background CO2 concentrations were measured. They showed the distinct diurnal variation, and were positively related with relative humidity, but negatively with temperature. The negative relation of CO2 measurements with temperature and the low CO2 concentrations during the day imply that CO2 depends on respiration. The daily variation of CO2 concentrations was damped with precipitation, which can be explained by dissolution of CO2 and gas release out of pores through the ground surface with recharge. For the injection test, 4.2 kg of CO2 was injected 1 m below the ground for about 30 minutes. In result, CO2 concentrations increased in all five chambers, which were located less than 2.5 m of distance from an injection point. The Chamber 1, which is closest to the injection point, showed the largest increase of CO2 concentrations; while Chamber 2, 3, and 4 showed the peak which is 2 times higher than the average of background CO2. The CO2 concentrations increased back after decreasing from the peak around 4 hours after the injection ended in Chamber 2, 4, and 5, which indicated that CO2 concentrations seem to be recovered to the background around 4 hours after the injection ended. To determine the leakage, the data in Chamber 2 and 5, which had low increase rates in the CO2 injection test, were used for statistical analysis. The result shows that the coefficient of variation (CV) of CO2 measurements for 30 minutes is efficient to determine a leakage signal, with reflecting the abnormal change in CO2

  6. CO2 dispersion modelling over Paris region within the CO2-MEGAPARIS project

    NASA Astrophysics Data System (ADS)

    Lac, C.; Donnelly, R. P.; Masson, V.; Pal, S.; Riette, S.; Donier, S.; Queguiner, S.; Tanguy, G.; Ammoura, L.; Xueref-Remy, I.

    2013-05-01

    Accurate simulation of the spatial and temporal variability of tracer mixing ratios over urban areas is a challenging and interesting task needed to be performed in order to utilise CO2 measurements in an atmospheric inverse framework and to better estimate regional CO2 fluxes. This study investigates the ability of a high-resolution model to simulate meteorological and CO2 fields around Paris agglomeration during the March field campaign of the CO2-MEGAPARIS project. The mesoscale atmospheric model Meso-NH, running at 2 km horizontal resolution, is coupled with the Town Energy Balance (TEB) urban canopy scheme and with the Interactions between Soil, Biosphere and Atmosphere CO2-reactive (ISBA-A-gs) surface scheme, allowing a full interaction of CO2 modelling between the surface and the atmosphere. Statistical scores show a good representation of the urban heat island (UHI) with stronger urban-rural contrasts on temperature at night than during the day by up to 7 °C. Boundary layer heights (BLH) have been evaluated on urban, suburban and rural sites during the campaign, and also on a suburban site over 1 yr. The diurnal cycles of the BLH are well captured, especially the onset time of the BLH increase and its growth rate in the morning, which are essential for tall tower CO2 observatories. The main discrepancy is a small negative bias over urban and suburban sites during nighttime (respectively 45 m and 5 m), leading to a few overestimations of nocturnal CO2 mixing ratios at suburban sites and a bias of +5 ppm. The diurnal CO2 cycle is generally well captured for all the sites. At the Eiffel tower, the observed spikes of CO2 maxima occur every morning exactly at the time at which the atmospheric boundary layer (ABL) growth reaches the measurement height. At suburban ground stations, CO2 measurements exhibit maxima at the beginning and at the end of each night, when the ABL is fully contracted, with a strong spatio-temporal variability. A sensitivity test without

  7. Laser Sounder for Measuring Atmospheric CO2 Concentrations: Progress Toward Ascends

    NASA Technical Reports Server (NTRS)

    Abshire, J. B.; Kawa, S. R.; Riris, H.; Allan, G. R.; Sun, X.; Stephen, M. A.; Wilson, E.; Burris, J. F.; Mao, J.

    2008-01-01

    the on and off-line singnals via the DIAL technique. We used pulsed laser signals, photon counting detectors, and time gating to isolate the laser returns from the surface, and to reject photons scattered from thin clouds and aerosols. High signal-to-noise ratios are required and the CO2 estimates can be sensitive to small drifts or other errors in the instrument, so the absorption estimates need to be quite stable for hours. We have constructed a breadboard version of the CO2 sensor that uses a low power fiber laser and a 20 cm diameter telescope. We have used it to make measurements of CO2 absorption in the laboratory and over 200-m to 2-km long open horizontal paths. These have been done in several sessions extending over multiple days, which allows us to assess the measurement stability and to compare absorption variations to readings from an external in situ CO2 sensor. We have also calculated characteristics of the technique for space including its expected measurement performance for different modulation types, and have performed an initial space mission accommodation study. We sill describe these results in the presentation.

  8. Laser Sounder for Measuring Atmospheric CO2 Concentrations: Progress Toward Ascends

    NASA Technical Reports Server (NTRS)

    Abshire, J. B.; Kawa, S. R.; Riris, H.; Allan, G. R.; Sun, X.; Stephen, M. A.; Wilson, E.; Burris, J. F.; Mao, J.

    2008-01-01

    the on and off-line singnals via the DIAL technique. We used pulsed laser signals, photon counting detectors, and time gating to isolate the laser returns from the surface, and to reject photons scattered from thin clouds and aerosols. High signal-to-noise ratios are required and the CO2 estimates can be sensitive to small drifts or other errors in the instrument, so the absorption estimates need to be quite stable for hours. We have constructed a breadboard version of the CO2 sensor that uses a low power fiber laser and a 20 cm diameter telescope. We have used it to make measurements of CO2 absorption in the laboratory and over 200-m to 2-km long open horizontal paths. These have been done in several sessions extending over multiple days, which allows us to assess the measurement stability and to compare absorption variations to readings from an external in situ CO2 sensor. We have also calculated characteristics of the technique for space including its expected measurement performance for different modulation types, and have performed an initial space mission accommodation study. We sill describe these results in the presentation.

  9. CO2-helium and CO2-neon mixtures at high pressures

    NASA Astrophysics Data System (ADS)

    Mallick, B.; Ninet, S.; Le Marchand, G.; Munsch, P.; Datchi, F.

    2013-01-01

    The properties of mixtures of carbon dioxide with helium or neon have been investigated as a function of CO2 concentration and pressure up to 30 GPa at room temperature. The binary phase diagrams of these mixtures are determined over the full range of CO2 concentrations using visual observations and Raman scattering measurements. Both diagrams are of eutectic type, with a fluid-fluid miscibility gap for CO2 concentrations in the range [5, 75] mol. % for He and [8, 55] mol. % for Ne, and a complete separation between the two components in the solid phase. The absence of alloys or stoichiometric compounds for these two binary systems is consistent with the Hume-Rothery rules of hard sphere mixtures. The Raman spectra and x-ray diffraction patterns of solid CO2 embedded in He or Ne for various initial concentrations have been measured up to 30 GPa and 12 GPa, respectively. The frequencies of the Raman modes and the volume of solid phase I are identical, within error bars, to those reported for 100% CO2 samples, thus confirming the total immiscibility of CO2 with He and Ne in the solid phase. These results demonstrate the possibility to perform high-pressure experiments on solid CO2 under (quasi-)hydrostatic conditions using He or Ne as pressure transmitting medium.

  10. Root-derived CO2 efflux via xylem stream rivals soil CO2 efflux.

    SciTech Connect

    Aubrey, Doug, P.; Teskey, Robert, O.

    2009-07-01

    • Respiration consumes a large portion of annual gross primary productivity in forest ecosystems and is dominated by belowground metabolism. Here, we present evidence of a previously unaccounted for internal CO2 flux of large magnitude from tree roots through stems. If this pattern is shown to persist over time and in other forests, it suggests that belowground respiration has been grossly underestimated. • Using an experimental Populus deltoides plantation as a model system, we tested the hypothesis that a substantial portion of the CO2 released from belowground autotrophic respiration remains within tree root systems and is transported aboveground through the xylem stream rather than diffusing into the soil atmosphere. • On a daily basis, the amount of CO2 that moved upward from the root system into the stem via the xylem stream (0.26 mol CO2 m-2 d-1) rivalled that which diffused from the soil surface to the atmosphere (0.27 mol CO2 m-2 d-1). We estimated that twice the amount of CO2 derived from belowground autotrophic respiration entered the xylem stream as diffused into the soil environment. • Our observations indicate that belowground autotrophic respiration consumes substantially more carbohydrates than previously recognized and challenge the paradigm that all root-respired CO2 diffuses into the soil atmosphere.

  11. CO2-helium and CO2-neon mixtures at high pressures.

    PubMed

    Mallick, B; Ninet, S; Le Marchand, G; Munsch, P; Datchi, F

    2013-01-28

    The properties of mixtures of carbon dioxide with helium or neon have been investigated as a function of CO(2) concentration and pressure up to 30 GPa at room temperature. The binary phase diagrams of these mixtures are determined over the full range of CO(2) concentrations using visual observations and Raman scattering measurements. Both diagrams are of eutectic type, with a fluid-fluid miscibility gap for CO(2) concentrations in the range [5, 75] mol. % for He and [8, 55] mol. % for Ne, and a complete separation between the two components in the solid phase. The absence of alloys or stoichiometric compounds for these two binary systems is consistent with the Hume-Rothery rules of hard sphere mixtures. The Raman spectra and x-ray diffraction patterns of solid CO(2) embedded in He or Ne for various initial concentrations have been measured up to 30 GPa and 12 GPa, respectively. The frequencies of the Raman modes and the volume of solid phase I are identical, within error bars, to those reported for 100% CO(2) samples, thus confirming the total immiscibility of CO(2) with He and Ne in the solid phase. These results demonstrate the possibility to perform high-pressure experiments on solid CO(2) under (quasi-)hydrostatic conditions using He or Ne as pressure transmitting medium.

  12. Effects of CO2 doped ice on CO2 and CH4 hydrate formation rates

    NASA Astrophysics Data System (ADS)

    Ambuehl, D.; Elwood-Madden, M.

    2012-12-01

    Reports of methane plumes on Mars have prompted the proposal of many source and reservoir models for methane, one of which is methane hydrate. A hydrate reservoir could sequester methane for prolonged periods. This reservoir could form as subsurface methane advects, coming into contact with a layer of permafrost. Within 1.5 m of the Martian surface, the permafrost is likely in communication with the Martian atmosphere. Therefore, diffused atmospheric gases in the ice, especially CO2, could affect hydrate formations rates. We tested the effects of diffused CO2 on gas hydrate formation rates using CO2 doped and ultrapure water ice. The resulting data was fit with a third order polynomial trend line and the instantaneous rates were determined using the first derivative of the headspace gas pressure vs. time curve and normalized for surface area. The results have shown that CO2 hydrate formation rates increased by half an order of magnitude and CH4 hydrate formation rates increased by an order of magnitude. The accelerated rate of CO2 hydrate formation is likely due to clathration of the diffused CO2, making further hydrate formation kinetically more favorable. The CH4 hydrate formation rates show a greater acceleration due to the thermodynamic stability imparted by a mixed hydrate phase. This indicates that CO2 trapped in the permafrost layer would facilitate the formation of near-surface methane hydrate on Mars.

  13. The Relationship Between CO2 Levels and CO2 Related Symptoms Reported on the ISS

    NASA Technical Reports Server (NTRS)

    VanBaalen, M.; Law, J.; Foy, M.; Wear, M. L.; Mason, S.; Mendez, C.; Meyers, V.

    2014-01-01

    Medical Operations, Toxicology, and the Lifetime Surveillance of Astronaut Health collaborated to assess the association of CO2 levels on board the International Space Station and USOS crew reported symptoms inflight, i.e. headache and vision changes. Private Medical Conference (PMC) documents and the weekly Space Medicine Operations Team (SMOT) Notes were used to provide a robust data set of inflight medical events. All events and non-events were documented independent of CO2 levels and other potential contributors. Average (arithmetic mean) and single point maximum ppCO2 was calculated for the 24 hours and 7 days prior to the PMC or SMOT date and time provided by LSAH. Observations falling within the first 7 days of flight (147) were removed from the datasets analyzed to avoid confounding with Space Adaptation Syndrome. The final analysis was based on 1716 observations. For headache, 46 headaches were observed. CO2 level, age at launch, time inflight, and data source were all significantly associated with headache. In particular, for each 1 mmHg increase in CO2, the odds of a crewmember reporting a headache doubled. For vision changes, 29 reports of vision changes were observed. These observations were not found to be statistically associated with CO2 levels as analyzed. While the incidence of headache has was not high (3%), headaches may be an indicator of underlying increases in intracranial pressure, which may result likely from the synergy between CO2-induced cerebral vasodilatation and decreased venous drainage in microgravity. Vision changes were inconsistently reported and as a result did not align appropriately with the CO2 levels. Further analysis is needed. Our results support ongoing efforts to lower the CO2 exposure limits in spacecraft.

  14. Geochemical Interaction of Middle Bakken Reservoir Rock and CO2 during CO2-Based Fracturing

    NASA Astrophysics Data System (ADS)

    Nicot, J. P.; Lu, J.; Mickler, P. J.; Ribeiro, L. H.; Darvari, R.

    2015-12-01

    This study was conducted to investigate the effects of geochemical interactions when CO2 is used to create the fractures necessary to produce hydrocarbons from low-permeability Middle Bakken sandstone. The primary objectives are to: (1) identify and understand the geochemical reactions related to CO2-based fracturing, and (2) assess potential changes of reservoir property. Three autoclave experiments were conducted at reservoir conditions exposing middle Bakken core fragments to supercritical CO2 (sc-CO2) only and to CO2-saturated synthetic brine. Ion-milled core samples were examined before and after the reaction experiments using scanning electron microscope, which enabled us to image the reaction surface in extreme details and unambiguously identify mineral dissolution and precipitation. The most significant changes in the reacted rock samples exposed to the CO2-saturated brine is dissolution of the carbonate minerals, particularly calcite which displays severely corrosion. Dolomite grains were corroded to a lesser degree. Quartz and feldspars remained intact and some pyrite framboids underwent slight dissolution. Additionally, small amount of calcite precipitation took place as indicated by numerous small calcite crystals formed at the reaction surface and in the pores. The aqueous solution composition changes confirm these petrographic observations with increase in Ca and Mg and associated minor elements and very slight increase in Fe and sulfate. When exposed to sc-CO2 only, changes observed include etching of calcite grain surface and precipitation of salt crystals (halite and anhydrite) due to evaporation of residual pore water into the sc-CO2 phase. Dolomite and feldspars remained intact and pyrite grains were slightly altered. Mercury intrusion capillary pressure tests on reacted and unreacted samples shows an increase in porosity when an aqueous phase is present but no overall porosity change caused by sc-CO2. It also suggests an increase in permeability

  15. High Power and Frequency-Agile Optical Parametric Oscillators for Airborne DIAL Measurements of CH4 and H2O

    NASA Astrophysics Data System (ADS)

    Nehrir, A. R.; Shuman, T.; Chuang, T.; Hair, J. W.; Refaat, T. F.; Ismail, S.; Kooi, S. A.; Notari, A.

    2014-12-01

    Atmospheric methane (CH4) has the second largest radiative forcing of the long-lived greenhouse gasses (GHG) after carbon dioxide. However, methane's much shorter atmospheric lifetime and much stronger warming potential make its radiative forcing equivalent to that for CO2 over a 20-year time horizon which makes CH4 a particularly attractive target for mitigation strategies. Similar to CH4, water vapor (H2O) is the most dominant of the short-lived GHG in the atmosphere and plays a key role in many atmospheric processes. Atmospheric H2O concentrations span over four orders of magnitude from the planetary boundary layer where high impact weather initiates to lower levels in the upper troposphere and lower stratosphere (UTLS) where water vapor has significant and long term impacts on the Earth's radiation budget. NASA Langley has fostered the technology development with Fibertek, Inc. to develop frequency agile and high power (> 3 W) pulsed lasers using similar architectures in the 1645 nm and 935 nm spectral bands for DIAL measurements of CH4 and H2O, respectively. Both systems utilize high power 1 kHz pulse repetition frequency Nd:YAG lasers to generate high power laser emission at the desired wavelength via optical parametric oscillators (OPO). The CH4 OPO, currently in its final build stage in a SBIR Phase II program has demonstrated >2 W average power with injection seeding from a distributed feedback (DFB) laser during risk reduction experiments. The H2O OPO has demonstrated high power operation (>2 W) during the SBIR Phase I program while being injection seeded with a DFB laser, and is currently funded via an SBIR Phase II to build a robust system for future integration into an airborne water vapor DIAL system capable of profiling from the boundary layer up to the UTLS. Both systems have demonstrated operation with active OPO wavelength control to allow for optimization of the DIAL measurements for operation at different altitudes and geographic regions. An

  16. Raman spectroscopy of CO 2-acetone and CO 2-ethanol complexes

    NASA Astrophysics Data System (ADS)

    Cabaço, M. Isabel; Danten, Y.; Tassaing, T.; Longelin, S.; Besnard, M.

    2005-09-01

    The IVV and IHV Raman profiles of the ν2 bending mode of CO 2 diluted in acetone and in ethanol have been measured at pressures up to 10 MPa at 313 K. Upon the addition of CO 2, the spectra exhibit a new polarised band interpreted as the spectral signature of transient electron donor-acceptor complexes formed between CO 2 and acetone or ethanol. This band is assigned to the lower frequency ν2(1) component of the bending mode after the degeneracy removal predicted in our previous work.

  17. CO2 mineralization-bridge between storage and utilization of CO2.

    PubMed

    Geerlings, Hans; Zevenhoven, Ron

    2013-01-01

    CO2 mineralization comprises a chemical reaction between suitable minerals and the greenhouse gas carbon dioxide. The CO2 is effectively sequestered as a carbonate, which is stable on geological timescales. In addition, the variety of materials that can be produced through mineralization could find applications in the marketplace, which makes implementation of the technology more attractive. In this article, we review recent developments and assess the current status of the CO2 mineralization field. In an outlook, we briefly describe a few mineralization routes, which upon further development have the potential to be implemented on a large scale.

  18. Effects of CO2 on stomatal conductance: do stomata open at very high CO2 concentrations?

    NASA Technical Reports Server (NTRS)

    Wheeler, R. M.; Mackowiak, C. L.; Yorio, N. C.; Sager, J. C.

    1999-01-01

    Potato and wheat plants were grown for 50 d at 400, 1000 and 10000 micromoles mol-1 carbon dioxide (CO2). and sweetpotato and soybean were grown at 1000 micromoles mol-1 CO2 in controlled environment chambers to study stomatal conductance and plant water use. Lighting was provided with fluorescent lamps as a 12 h photoperiod with 300 micromoles m-2 s-1 PAR. Mid-day stomatal conductances for potato were greatest at 400 and 10000 micromoles mol-1 and least at 1000 micromoles mol-1 CO2. Mid-day conductances for wheat were greatest at 400 micromoles mol-1 and least at 1000 and 10000 micromoles mol-1 CO2. Mid-dark period conductances for potato were significantly greater at 10000 micromoles mol-1 than at 400 or 1000 micromoles mol-1, whereas dark conductance for wheat was similar in all CO2 treatments. Temporarily changing the CO2 concentration from the native 1000 micromoles mol-1 to 400 micromoles mol-1 increased mid-day conductance for all species, while temporarily changing from 1000 to 10000 micromoles mol-1 also increased conductance for potato and sweetpotato. Temporarily changing the dark period CO2 from 1000 to 10000 micromoles mol-1 increased conductance for potato, soybean and sweetpotato. In all cases, the stomatal responses were reversible, i.e. conductances returned to original rates following temporary changes in CO2 concentration. Canopy water use for potato was greatest at 10000, intermediate at 400, and least at 1000 micromoles mol-1 CO2, whereas canopy water use for wheat was greatest at 400 and similar at 1000 and 10000 micromoles mol-1 CO2. Elevated CO2 treatments (i.e. 1000 and 10000 micromoles mol-1) resulted in increased plant biomass for both wheat and potato relative to 400 micromoles mol-1, and no injurious effects were apparent from the 10000 micromoles mol-1 treatment. Results indicate that super-elevated CO2 (i.e. 10000 micromoles mol-1) can increase stomatal conductance in some species, particularly during the dark period, resulting in

  19. Effects of CO2 on stomatal conductance: do stomata open at very high CO2 concentrations?

    NASA Technical Reports Server (NTRS)

    Wheeler, R. M.; Mackowiak, C. L.; Yorio, N. C.; Sager, J. C.

    1999-01-01

    Potato and wheat plants were grown for 50 d at 400, 1000 and 10000 micromoles mol-1 carbon dioxide (CO2). and sweetpotato and soybean were grown at 1000 micromoles mol-1 CO2 in controlled environment chambers to study stomatal conductance and plant water use. Lighting was provided with fluorescent lamps as a 12 h photoperiod with 300 micromoles m-2 s-1 PAR. Mid-day stomatal conductances for potato were greatest at 400 and 10000 micromoles mol-1 and least at 1000 micromoles mol-1 CO2. Mid-day conductances for wheat were greatest at 400 micromoles mol-1 and least at 1000 and 10000 micromoles mol-1 CO2. Mid-dark period conductances for potato were significantly greater at 10000 micromoles mol-1 than at 400 or 1000 micromoles mol-1, whereas dark conductance for wheat was similar in all CO2 treatments. Temporarily changing the CO2 concentration from the native 1000 micromoles mol-1 to 400 micromoles mol-1 increased mid-day conductance for all species, while temporarily changing from 1000 to 10000 micromoles mol-1 also increased conductance for potato and sweetpotato. Temporarily changing the dark period CO2 from 1000 to 10000 micromoles mol-1 increased conductance for potato, soybean and sweetpotato. In all cases, the stomatal responses were reversible, i.e. conductances returned to original rates following temporary changes in CO2 concentration. Canopy water use for potato was greatest at 10000, intermediate at 400, and least at 1000 micromoles mol-1 CO2, whereas canopy water use for wheat was greatest at 400 and similar at 1000 and 10000 micromoles mol-1 CO2. Elevated CO2 treatments (i.e. 1000 and 10000 micromoles mol-1) resulted in increased plant biomass for both wheat and potato relative to 400 micromoles mol-1, and no injurious effects were apparent from the 10000 micromoles mol-1 treatment. Results indicate that super-elevated CO2 (i.e. 10000 micromoles mol-1) can increase stomatal conductance in some species, particularly during the dark period, resulting in

  20. Effects of CO2 on stomatal conductance: do stomata open at very high CO2 concentrations?

    PubMed

    Wheeler, R M; Mackowiak, C L; Yorio, N C; Sager, J C

    1999-03-01

    Potato and wheat plants were grown for 50 d at 400, 1000 and 10000 micromoles mol-1 carbon dioxide (CO2). and sweetpotato and soybean were grown at 1000 micromoles mol-1 CO2 in controlled environment chambers to study stomatal conductance and plant water use. Lighting was provided with fluorescent lamps as a 12 h photoperiod with 300 micromoles m-2 s-1 PAR. Mid-day stomatal conductances for potato were greatest at 400 and 10000 micromoles mol-1 and least at 1000 micromoles mol-1 CO2. Mid-day conductances for wheat were greatest at 400 micromoles mol-1 and least at 1000 and 10000 micromoles mol-1 CO2. Mid-dark period conductances for potato were significantly greater at 10000 micromoles mol-1 than at 400 or 1000 micromoles mol-1, whereas dark conductance for wheat was similar in all CO2 treatments. Temporarily changing the CO2 concentration from the native 1000 micromoles mol-1 to 400 micromoles mol-1 increased mid-day conductance for all species, while temporarily changing from 1000 to 10000 micromoles mol-1 also increased conductance for potato and sweetpotato. Temporarily changing the dark period CO2 from 1000 to 10000 micromoles mol-1 increased conductance for potato, soybean and sweetpotato. In all cases, the stomatal responses were reversible, i.e. conductances returned to original rates following temporary changes in CO2 concentration. Canopy water use for potato was greatest at 10000, intermediate at 400, and least at 1000 micromoles mol-1 CO2, whereas canopy water use for wheat was greatest at 400 and similar at 1000 and 10000 micromoles mol-1 CO2. Elevated CO2 treatments (i.e. 1000 and 10000 micromoles mol-1) resulted in increased plant biomass for both wheat and potato relative to 400 micromoles mol-1, and no injurious effects were apparent from the 10000 micromoles mol-1 treatment. Results indicate that super-elevated CO2 (i.e. 10000 micromoles mol-1) can increase stomatal conductance in some species, particularly during the dark period, resulting in

  1. CO2 permeability of fractured cap rocks - experiments and numerical simulations (CO2Seals)

    NASA Astrophysics Data System (ADS)

    (Draeger), Ines Rick; Clauser, Christoph

    2010-05-01

    In CO2 sequestration and underground gas storage the sealing capacity of a cap rock is of paramount importance. The main question is therefore how the leakage of CO2 through fissures and faults within the cap rock may affect the CO2 sealing efficiency of low-permeable seal lithotypes. In many cases, these structures provide the main pathways for leakage of CO2. Here, we provide an overview of one part of the joint research project CO2Seals, which deals with the effect of structural features - such as tectonic faults and fissures in the overburden - on the migration of CO2 in addition to mineralogical, petrophysical, and geochemical properties of different lithotypes. The primary contribution of the entire project consists of an improvement of the present quantitative understanding of CO2 transport and retention processes and associated interactions in cap rocks between rock and CO2 or brine. To this end, we are adapting different numerical tools for simulating the relevant petrophysical and geochemical processes of CO2 in cap rocks, in close operation with: (1) large-scale CO2-percolation experiments on fractured cap rock samples; (2) permeability, gas breakthrough, and diffusion experiments; (3) measurements of the mechanical stability of cap rocks and the geochemical alterations of fault zone rock. The observed resulting changes in petrophysical properties, such as porosity, relative rock permeability (CO2 and brine), and fault permeability provide basics for the following numerical simulations. For example, first permeability tests of a marl and clay cap rock out of Cretaceous and Jurassic formations revealed gas permeability of 10-18 m2 down to 10-22 m2. In addition, first percolation experiments indicated that the influence of fault zones on the measured CO2 permeability of clays is very low. Furthermore, numerical bench-scale models are performed to provide confidence for the subsequent transfer to reservoir systems. Large-scale numerical models were created

  2. Increasing CO2 threatens human nutrition.

    PubMed

    Myers, Samuel S; Zanobetti, Antonella; Kloog, Itai; Huybers, Peter; Leakey, Andrew D B; Bloom, Arnold J; Carlisle, Eli; Dietterich, Lee H; Fitzgerald, Glenn; Hasegawa, Toshihiro; Holbrook, N Michele; Nelson, Randall L; Ottman, Michael J; Raboy, Victor; Sakai, Hidemitsu; Sartor, Karla A; Schwartz, Joel; Seneweera, Saman; Tausz, Michael; Usui, Yasuhiro

    2014-06-05

    Dietary deficiencies of zinc and iron are a substantial global public health problem. An estimated two billion people suffer these deficiencies, causing a loss of 63 million life-years annually. Most of these people depend on C3 grains and legumes as their primary dietary source of zinc and iron. Here we report that C3 grains and legumes have lower concentrations of zinc and iron when grown under field conditions at the elevated atmospheric CO2 concentration predicted for the middle of this century. C3 crops other than legumes also have lower concentrations of protein, whereas C4 crops seem to be less affected. Differences between cultivars of a single crop suggest that breeding for decreased sensitivity to atmospheric CO2 concentration could partly address these new challenges to global health.

  3. Retrospective Analysis Of CO2 Laser Myringotomy

    NASA Astrophysics Data System (ADS)

    Lipman, Sidney P.; Guelcher, Robert T.

    1988-06-01

    A retrospective review of the author's series of 91 carbon dioxide (CO2) laser myringotomy cases performed between 1983 and 1986 is presented. Patients with chronic otitis media with effusion (COME) were selected on the basis of possible benefit from shorter ventilation time than tympanostomy tube insertion. The proceedings were performed on an outpatient basis with topical iontophoretic anesthesia, which offers significant cost savings and a lack of possible complications. The CO2 laser gives clean precise 0.8mm perforations which remain open for 2-4 weeks, this shorter ventilation time minimizing the period of water precautions and other side effects. The laser perforations heal well. With a success rate of 52 % reported, which could be increased with careful patient selection, we feel that the advantages of carbon dioxide laser myringotomy over myringotomy plus intubation outweight the risk of recurrent otitis media with effusion formation in those patients to whom this procedure is applicable.

  4. Streamer parameters and breakdown in CO2

    NASA Astrophysics Data System (ADS)

    Seeger, M.; Avaheden, J.; Pancheshnyi, S.; Votteler, T.

    2017-01-01

    CO2 is a promising gas for the replacement of SF6 in high-voltage transmission and distribution networks due to its lower environmental impact. The insulation properties of CO2 are, therefore, of great interest. For this, the properties of streamers are important, since they determine the initial discharge propagation and possibly the transition to a leader. The present experimental investigation addresses the streamer inception and propagation at ambient temperature in the pressure range 0.05-0.5 MPa at both polarities. Streamer parameters, namely the stability field, radius and velocity, were deduced in uniform and in strongly non-uniform background fields. The measured breakdown fields can then be understood by streamer propagation and streamer-to-leader transition.

  5. Aridity under conditions of increased CO2

    NASA Astrophysics Data System (ADS)

    Greve, Peter; Roderick, Micheal L.; Seneviratne, Sonia I.

    2016-04-01

    A string of recent of studies led to the wide-held assumption that aridity will increase under conditions of increasing atmospheric CO2 concentrations and associated global warming. Such results generally build upon analyses of changes in the 'aridity index' (the ratio of potential evaporation to precipitation) and can be described as a direct thermodynamic effect on atmospheric water demand due to increasing temperatures. However, there is widespread evidence that contradicts the 'warmer is more arid' interpretation, leading to the 'global aridity paradox' (Roderick et al. 2015, WRR). Here we provide a comprehensive assessment of modeled changes in a broad set of dryness metrics (primarily based on a range of measures of water availability) over a large range of realistic atmospheric CO2 concentrations. We use an ensemble of simulations from of state-of-the-art climate models to analyse both equilibrium climate experiments and transient historical simulations and future projections. Our results show that dryness is, under conditions of increasing atmospheric CO2 concentrations and related global warming, generally decreasing at global scales. At regional scales we do, however, identify areas that undergo changes towards drier conditions, located primarily in subtropical climate regions and the Amazon Basin. Nonetheless, the majority of regions, especially in tropical and mid- to northern high latitudes areas, display wetting conditions in a warming world. Our results contradict previous findings and highlight the need to comprehensively assess all aspects of changes in hydroclimatological conditions at the land surface. Roderick, M. L., P. Greve, and G. D. Farquhar (2015), On the assessment of aridity with changes in atmospheric CO2, Water Resour. Res., 51, 5450-5463

  6. Pulpotomies with CO2 laser in dogs

    NASA Astrophysics Data System (ADS)

    Figueiredo, Jose A. P.; Chavantes, Maria C.; Gioso, Marco A.; Pesce, Hildeberto F.; Jatene, Adib D.

    1995-05-01

    The aim of this study was to evaluate the clinical aspects of dental pulps submitted to shallow pulpotomy followed by CO2 laser radiation at five different procedures. For this purpose, initially 66 dogs' teeth were opened and about 2 or 3 mm of coronal dental pulp was removed. Continuous irrigation with saline solution was implemented. The teeth were randomly divided into 6 groups of 11 each. After cessation of bleeding, in group I, CO2 laser (Xanar-20, USA) was irradiated for 1 second at a power of 5 watts; in group II, 2 seconds at 3 watts; in Group III, 2 seconds at 5 watts; in Group IV, 1 second at 3 watts; in Group V, a continuous mode at 3 watts; Group VI served as a control, with no laser irradiation. The results showed no clinical differences between the 3 W and 5 W powers. Time period of irradiation exposition influenced definitively the clinical appearance of the dental pulps. Groups I and IV (1 second) were unable to stop the bleeding, which persisted over 15 minutes for all teeth. This may be due to the intense heat generated by CO2 laser, causing vasodilatation. Groups II and III displayed a similar appearance, but bleeding stopped in about 10 minutes. Group V (continuous mode) had no bleeding after irradiation, but a plasma-like liquid would come out for almost 2 minutes. When comparing to the control (Group VI), all the pulps would assume a jelly-like aspect, with black granulated tissue on the surface, covering totally the pulps of Group V and partially the other groups. The histological results will be discussed in a further study. From the data obtained, it seems that CO2 laser irradiation for pulpotomies should be done in a continuous mode, for clinical convenience in terms of time taken and effective irradiation.

  7. Continuous CO2 extractor and methods

    SciTech Connect

    None listed

    2010-06-15

    The purpose of this CRADA was to assist in technology transfer from Russia to the US and assist in development of the technology improvements and applications for use in the U.S. and worldwide. Over the period of this work, ORNL has facilitated design, development and demonstration of a low-pressure liquid extractor and development of initial design for high-pressure supercritical CO2 fluid extractor.

  8. New Electronic Materials and CO2 Reduction.

    DTIC Science & Technology

    1988-02-02

    Curie Point determination. 3. The extension of the H2 reduction studies to CO- using rhodium - catalysts dispersed on ZrO 2 . TI or .. ..... PO A. Page...current of 240 mA with an overall current efficiency greater than 36%. Yhe addition of colloidal metal particles to solutions containing benzene - 21...continual renewal e the qcti,- oatlyst surface. Preliminary experiments carried out on the reduction of CO 2 with hydrogen using a metallic rhodium catalyst

  9. Towards Overhauser DNP in supercritical CO2

    NASA Astrophysics Data System (ADS)

    van Meerten, S. G. J.; Tayler, M. C. D.; Kentgens, A. P. M.; van Bentum, P. J. M.

    2016-06-01

    Overhauser Dynamic Nuclear Polarization (ODNP) is a well known technique to improve NMR sensitivity in the liquid state, where the large polarization of an electron spin is transferred to a nucleus of interest by cross-relaxation. The efficiency of the Overhauser mechanism for dipolar interactions depends critically on fast local translational dynamics at the timescale of the inverse electron Larmor frequency. The maximum polarization enhancement that can be achieved for 1H at high magnetic fields benefits from a low viscosity solvent. In this paper we investigate the option to use supercritical CO2 as a solvent for Overhauser DNP. We have investigated the diffusion constants and longitudinal nuclear relaxation rates of toluene in high pressure CO2. The change in 1H T1 by addition of TEMPO radical was analyzed to determine the Overhauser cross-relaxation in such a mixture, and is compared with calculations based on the Force Free Hard Sphere (FFHS) model. By analyzing the relaxation data within this model we find translational correlation times in the range of 2-4 ps, depending on temperature, pressure and toluene concentration. Such short correlation times may be instrumental for future Overhauser DNP applications at high magnetic fields, as are commonly used in NMR. Preliminary DNP experiments have been performed at 3.4 T on high pressure superheated water and model systems such as toluene in high pressure CO2.

  10. Towards Overhauser DNP in supercritical CO(2).

    PubMed

    van Meerten, S G J; Tayler, M C D; Kentgens, A P M; van Bentum, P J M

    2016-06-01

    Overhauser Dynamic Nuclear Polarization (ODNP) is a well known technique to improve NMR sensitivity in the liquid state, where the large polarization of an electron spin is transferred to a nucleus of interest by cross-relaxation. The efficiency of the Overhauser mechanism for dipolar interactions depends critically on fast local translational dynamics at the timescale of the inverse electron Larmor frequency. The maximum polarization enhancement that can be achieved for (1)H at high magnetic fields benefits from a low viscosity solvent. In this paper we investigate the option to use supercritical CO2 as a solvent for Overhauser DNP. We have investigated the diffusion constants and longitudinal nuclear relaxation rates of toluene in high pressure CO2. The change in (1)H T1 by addition of TEMPO radical was analyzed to determine the Overhauser cross-relaxation in such a mixture, and is compared with calculations based on the Force Free Hard Sphere (FFHS) model. By analyzing the relaxation data within this model we find translational correlation times in the range of 2-4ps, depending on temperature, pressure and toluene concentration. Such short correlation times may be instrumental for future Overhauser DNP applications at high magnetic fields, as are commonly used in NMR. Preliminary DNP experiments have been performed at 3.4T on high pressure superheated water and model systems such as toluene in high pressure CO2. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. CO2 flux geothermometer for geothermal exploration

    NASA Astrophysics Data System (ADS)

    Harvey, M. C.; Rowland, J. V.; Chiodini, G.; Rissmann, C. F.; Bloomberg, S.; Fridriksson, T.; Oladottir, A. A.

    2017-09-01

    A new geothermometer (TCO2 Flux) is proposed based on soil diffuse CO2 flux and shallow temperature measurements made on areas of steam heated, thermally altered ground above active geothermal systems. This CO2 flux geothermometer is based on a previously reported CO2 geothermometer that was designed for use with fumarole analysis. The new geothermometer provides a valuable additional exploration tool for estimating subsurface temperatures in high-temperature geothermal systems. Mean TCO2 Flux estimates fall within the range of deep drill hole temperatures at Wairakei (New Zealand), Tauhara (New Zealand), Rotokawa (New Zealand), Ohaaki (New Zealand), Reykjanes (Iceland) and Copahue (Argentina). The spatial distribution of geothermometry estimates is consistent with the location of major upflow zones previously reported at the Wairakei and Rotokawa geothermal systems. TCO2 Flux was also evaluated at White Island (New Zealand) and Reporoa (New Zealand), where limited sub-surface data exists. Mode TCO2 Flux at White Island is high (320 °C), the highest of the systems considered in this study. However, the geothermometer relies on mineral-water equilibrium in neutral pH reservoir fluids, and would not be reliable in such an active and acidic environment. Mean TCO2 Flux at Reporoa (310 °C) is high, which indicates Reporoa has a separate upflow from the nearby Waiotapu geothermal system; an outflow from Waiotapu would not be expected to have such high temperature.

  12. Breadboard CO2 and humidity control system

    NASA Technical Reports Server (NTRS)

    Boehm, A. M.

    1976-01-01

    A regenerable CO2 and humidity control system is being developed for potential use on shuttle as an alternate to the baseline lithium hydroxide (LiOH)/condensing heat exchanger system. The system utilizes a sorbent material, designated HS-C, to adsorb CO2 and water vapor from the cabin atmosphere. The material is regenerated by exposing it to space vacuum. A half-size breadboard system, utilizing a flight representative HS-C canister, was designed, built, and performance tested to shuttle requirements for total CO2 and total humidity removal. The use of a new chemical matrix material allowed significant optimization of the system design by packing the HS-C chemical into the core of a heat exchanger which is manifolded to form two separate and distinct beds. Breadboard system performance was proven by parametric testing and simulated mission testing over the full range of shuttle crew sizes and metabolic loadings. Vacuum desorption testing demonstrated considerable savings in previously projected shuttle vacuum duct sizing.

  13. CO 2 laser cutting of slate

    NASA Astrophysics Data System (ADS)

    Boutinguiza, M.; Pou, J.; Lusquiños, F.; Quintero, F.; Soto, R.; Pérez-Amor, M.; Watkins, K.; Steen, W. M.

    2002-01-01

    Slate is a natural stone which has the characteristic that shows a well-developed defoliation plane, allowing to easily split it in plates parallel to that plane which are particularly used as tiles for roof building. At present, the manufacturing of slate is mostly manual, being noisy, powdery and unsafe for the worker. Thus, there is a need to introduce new processing methods in order to improve both the working conditions and the quality of the products made of slate. Following the previous work focused on the drilling and cutting of slate tiles using a Nd : YAG laser, we present in this paper the results of the work carried out to explore the possibilities to cut slate plates by using a CO 2 laser. A 1.5 kW CO 2 laser was used to perform different experiments in which, the influence of some processing parameters (average power, assist gas pressure) on the geometry and quality of the cut was studied. The results obtained show that the CO 2 laser is a feasible tool for a successful cutting of slate.

  14. Martian Gullies: Formation by CO2 Fluidification

    NASA Astrophysics Data System (ADS)

    Cedillo-Flores, Y.; Durand-Manterola, H. J.

    2006-12-01

    Some of the geomorphological features in Mars are the gullies. Some theories developed tried explain its origin, either by liquid water, liquid carbon dioxide or flows of dry granular material. We made a comparative analysis of the Martian gullies with the terrestrial ones. We propose that the mechanism of formation of the gullies is as follows: In winter CO2 snow mixed with sand falls in the terrain. In spring the CO2 snow sublimate and gaseous CO2 make fluid the sand which flows like liquid eroding the terrain and forming the gullies. By experimental work with dry granular material, we simulated the development of the Martian gullies injecting air in the granular material. We present the characteristics of some terrestrial gullies forms at cold environment, sited at Nevado de Toluca Volcano near Toluca City, México. We compare them with Martian gullies choose from four different areas, to target goal recognize or to distinguish, (to identify) possible processes evolved in its formation. Also, we measured the lengths of those Martian gullies and the range was from 24 m to 1775 meters. Finally, we present results of our experimental work at laboratory with dry granular material.

  15. Low-Power CO2 Compression Technology

    NASA Technical Reports Server (NTRS)

    Finn, John E.; Sridhar, K. R.; Kliss, Mark (Technical Monitor)

    1998-01-01

    Presently, the most feasible processes for extracting oxygen from the Martian atmosphere either require or are much more efficient if the atmospheric CO2 feed is provided at pressures well above the Martian ambient. Electrical power for performing the desired compression is likely to be an extremely limited resource on the Mars surface. Even if "cheap" nuclear power is available at a central site/launch facility where rocket propellent and oxidant are manufactured, life support applications needing oxygen production capabilities, such as rovers, portable life support, and remote or independent exploration stations, will benefit from extremely low-power atmospheric compression technology, such as the one discussed here. Our experiments show the potential of one very low-power approach to performing CO2 compression that uses the Mars diurnal temperature cycle to drive a heat engine. The 1 kg compressor has been tested over an extended period in a Mars environmental simulation chamber that mimics the composition, pressure, and temperature cycles that can occur on the Martian surface. The simple design, which has very few moving parts and can easily be scaled to larger or smaller sizes, produces a CO2 stream at a rate of 100 g/ day at a quality and pressure suitable for a variety of oxygen production processes.

  16. Ultraviolet DIAL measurements of O3 profiles in regions of spatially inhomogeneous aerosols. [differential absorption lidar

    NASA Technical Reports Server (NTRS)

    Browell, E. V.; Shipley, S. T.; Ismail, S.

    1985-01-01

    The differential absorption lidar (DIAL) technique generally assumes that atmospheric optical scattering is the same at the two laser wavelengths used in the DIAL measurement of a gas concentration profile. Erros can arise in this approach when the wavelengths are significantly separated, and there is a range dependence in the aerosol scattering distribution. This paper discusses the errors introduced by large DIAL wavelength separations and spatial inhomogeneity of aerosols in the atmosphere. A Bernoulli solution for determining the relative distribution of aerosol backscattering in the UV region is presented, and scattering ratio boundary values for these solutions are discussed. The results of this approach are used to derive a backscatter correction to the standard DIAL analysis method. It is shown that for the worst cases of severe range dependence in aerosol backscattering, the residual errors in the corrected DIAL O3 measurements were less than 10 ppbv for DIAL wavelengths at 286 and 300 nm.

  17. Correction of Doppler-broadened Rayleigh backscattering effects in H2O dial measurements

    NASA Technical Reports Server (NTRS)

    Ansmann, A.; Bosenberg, J.

    1986-01-01

    A general method of solutions for treating effects of Doppler-broadened Rayleigh backscattering in H2O Differential Absorption Lidar (DIAL) measurements are described and discussed. Errors in vertical DIAL measuremtns caused by this laser line broadening effect can be very large and, therfore, this effect has to be accounted for accurately. To analyze and correct effects of Doppler-broadened Rayleigh backscattering in DIAL experiments, a generalized DIAL approximation was derived starting from a lidar equation, which includes Doppler broadening. To evaluate the accuracy of H2O DIAL measurements, computer simulations were performed. It was concluded that correction of Doppler broadened Rayleigh backscattering is possible with good accuracy in most cases of tropospheric H2O DIAL measurements, but great care has to be taken when layers with steep gradients of Mie backscattering like clouds or inversion layers are present.

  18. Global CO2 rise leads to reduced maximum stomatal conductance in Florida vegetation

    PubMed Central

    Lammertsma, Emmy I.; de Boer, Hugo Jan; Dekker, Stefan C.; Dilcher, David L.; Lotter, André F.; Wagner-Cremer, Friederike

    2011-01-01

    A principle response of C3 plants to increasing concentrations of atmospheric CO2 (CO2) is to reduce transpirational water loss by decreasing stomatal conductance (gs) and simultaneously increase assimilation rates. Via this adaptation, vegetation has the ability to alter hydrology and climate. Therefore, it is important to determine the adaptation of vegetation to the expected anthropogenic rise in CO2. Short-term stomatal opening–closing responses of vegetation to increasing CO2 are described by free-air carbon enrichments growth experiments, and evolutionary adaptations are known from the geological record. However, to date the effects of decadal to centennial CO2 perturbations on stomatal conductance are still largely unknown. Here we reconstruct a 34% (±12%) reduction in maximum stomatal conductance (gsmax) per 100 ppm CO2 increase as a result of the adaptation in stomatal density (D) and pore size at maximal stomatal opening (amax) of nine common species from Florida over the past 150 y. The species-specific gsmax values are determined by different evolutionary development, whereby the angiosperms sampled generally have numerous small stomata and high gsmax, and the conifers and fern have few large stomata and lower gsmax. Although angiosperms and conifers use different D and amax adaptation strategies, our data show a coherent response in gsmax to CO2 rise of the past century. Understanding these adaptations of C3 plants to rising CO2 after decadal to centennial environmental changes is essential for quantification of plant physiological forcing at timescales relevant for global warming, and they are likely to continue until the limits of their phenotypic plasticity are reached. PMID:21330552

  19. Discriminating and continuous measurement of photosynthesis and respiration by monitoring 13CO2 and 12CO2 as tracers.

    PubMed

    Nishi, I; Futami, J; Ma, P; Ishii, H; Takakura, T; Goto, E

    1996-12-01

    The simultaneous and discriminative measurement of the photosynthesis and the respiration of the plant was attained by simultaneous monitoring of 13CO2 and 12CO2 by artificial control of 13CO2 abundance of ambient air. The principle of the measurement is based on the following physiological processes. 6CO2 + 12H2O --> C6H12O6 + 6O2 + 6H2O, 6(13C)O2 + 12H2O --> (13C6)H12O6 + 6O2 + 6H2O, 6CO2 + 12H2(18O) --> C6H12O6 + 6(18O)18O + 6H20. Assuming that respiratory consumption of the new born carbon substrate fixed by photosynthesis is negligible during the measurement, the photosynthetic CO2 consumption VPCO2 and the respiratory CO2 production VRCO2 are measured according to the estimation (1) or (2), (1) for closed method, VPCO2 = k(V0 - V t)¿ F13CO2 + (F12CO2/F13CO2)F13CO2 ¿, VRCO2 = k(V0 - V t)¿ F12CO2 - (F12CO2/F13CO2)F13CO2 ¿, (2) for open method, VPCO2 = kVE ¿ (FI13CO2 - FE13CO2) + (F12CO2/F13CO2)(FI13CO2 - FE13CO2) ¿, VRCO2 = kVE ¿ (FI12CO2 - FE12CO2) - (F12CO2/F13CO2)(FI13CO2 - FE13CO2) ¿ where V0 is initial volume of growth chamber including attached flexible bag, FICO2 is the inlet or initial gas concentration of CO2 and FECO2 is the ambient gas concentration of CO2 in the chamber, V and VE are the sampling rate of mass spectrometer and the ventilation rate of the growth chamber respectively, k is the STPD conversion factor = ¿273(PB-PH2O)/760(273+tE)¿, tE(degrees C) is the ambient gas temperature. In the closed method, the gas container of the growth chamber is circulated, resulting FECO2 is varied according to the balance of consumption and production of CO2, while in the open method VE is controlled to keep FECO2 at a constant value. Both (1) and (2) methods were examined and evaluated on the measurements of komatsuna and maize.

  20. Range Resolved CO2 Atmospheric Backscattering Measurements Using Fiber Lasers and RZPN Code Modulation

    NASA Astrophysics Data System (ADS)

    Burris, J.; Sun, X.

    2011-12-01

    We report the use of a return-to- zero (RZPN) pseudo noise modulation technique for making range resolved measurements of CO2 within the planetary boundary layer (PBL) using commercial, off-the-shelf, components. Conventional, range resolved, DIAL measurements require laser pulse widths that are significantly shorter than the desired spatial resolution and necessitate using pulses whose temporal spacing is such that scattered returns from only a single pulse are observed by the receiver at any one time (for the PBL pulse separations must be >~20 microseconds). This imposes significant operational limitations when using currently available fiber lasers because of the resulting low duty cycle (<~0.0005) and consequent low average laser output power. The RZPN modulation technique enables a fiber laser to operate at much higher duty cycles (approaching 0.04) thereby more effectively utilizing the amplifier's output. This increases the counts received by approximately two orders of magnitude. Our approach involves employing two distributed feedback lasers (DFB), each modulated by a different RPZN code, whose outputs are then amplified by a CW fiber amplifier. One laser is tuned to a CO2 absorption line; the other operates offline thereby permitting the simultaneous acquisition of both on and offline signals using independent RZPN codes. This minimizes the impact of atmospheric turbulence on the measurement. The on and offline signals are retrieved by deconvolving the return signal using the appropriate kernels. An assessment of the technique, discussions of measurement precision and error sources as well as preliminary data will be presented.

  1. Range Resolved CO2 Atmospheric Backscattering Measurements Using Fiber Lasers and RZPN Code Modulation

    NASA Technical Reports Server (NTRS)

    Burris, John

    2011-01-01

    We report the use of a return-to- zero (RZPN) pseudo noise modulation technique for making range resolved measurements of CO2 within the planetary boundary layer (PBL) using commercial, off-the-shelf, components. Conventional, range resolved, DIAL measurements require laser pulse widths that are significantly shorter than the desired spatial resolution and necessitate using pulses whose temporal spacing is such that scattered returns from only a single pulse are observed by the receiver at any one time (for the PBL pulse separations must be greater than approximately 20 microseconds). This imposes significant operational limitations when using currently available fiber lasers because of the resulting low duty cycle (less than approximately 0.0005) and consequent low average laser output power. The RZPN modulation technique enables a fiber laser to operate at much higher duty cycles (approaching 0.04) thereby more effectively utilizing the amplifier's output. This increases the counts received by approximately two orders of magnitude. Our approach involves employing two distributed feedback lasers (DFB), each modulated by a different RPZN code, whose outputs are then amplified by a CW fiber amplifier. One laser is tuned to a CO2 absorption line; the other operates offline thereby permitting the simultaneous acquisition of both on and offline signals using independent RZPN codes. This minimizes the impact of atmospheric turbulence on the measurement. The on and offline signals are retrieved by deconvolving the return signal using the appropriate kernels.

  2. Biosequestration of atmospheric CO2 and flue gas-containing CO2 by microalgae.

    PubMed

    Cheah, Wai Yan; Show, Pau Loke; Chang, Jo-Shu; Ling, Tau Chuan; Juan, Joon Ching

    2015-05-01

    The unceasing rise of greenhouse gas emission has led to global warming and climate change. Global concern on this phenomenon has put forward the microalgal-based CO2 sequestration aiming to sequester carbon back to the biosphere, ultimately reducing greenhouse effects. Microalgae have recently gained enormous attention worldwide, to be the valuable feedstock for renewable energy production, due to their high growth rates, high lipid productivities and the ability to sequester carbon. The photosynthetic process of microalgae uses atmospheric CO2 and CO2 from flue gases, to synthesize nutrients for their growth. In this review article, we will primarily discuss the efficiency of CO2 biosequestration by microalgae species, factors influencing microalgal biomass productions, microalgal cultivation systems, the potential and limitations of using flue gas for microalgal cultivation as well as the bio-refinery approach of microalgal biomass.

  3. Integration of the electrochemical depolorized CO2 concentrator with the Bosch CO2 reduction subsystem

    NASA Technical Reports Server (NTRS)

    Schubert, F. H.; Wynveen, R. A.; Hallick, T. M.

    1976-01-01

    Regenerative processes for the revitalization of spacecraft atmospheres require an Oxygen Reclamation System (ORS) for the collection of carbon dioxide and water vapor and the recovery of oxygen from these metabolic products. Three life support subsystems uniquely qualified to form such an ORS are an Electrochemical CO2 Depolarized Concentrator (EDC), a CO2 Reduction Subsystem (BRS) and a Water Electrolysis Subsystem (WES). A program to develop and test the interface hardware and control concepts necessary for integrated operation of a four man capacity EDC with a four man capacity BRS was successfully completed. The control concept implemented proved successful in operating the EDC with the BRS for both constant CO2 loading as well as variable CO2 loading, based on a repetitive mission profile of the Space Station Prototype (SSP).

  4. Polymeric nanoporous materials fabricated with supercritical CO2 and CO2-expanded liquids.

    PubMed

    Zhang, Aijuan; Zhang, Qingkun; Bai, Hua; Li, Lei; Li, Jun

    2014-01-01

    Both academia and industries have put great efforts into developing non-destructive technologies for the fabrication of polymeric nanoporous materials. Such non-destructive technologies developed with supercritical CO2 (scCO2) and CO2-expanded liquids (CXLs) have been attracting more and more attention because they have been demonstrated to be green and effective media for porous polymer preparation and processing. In this tutorial review, we present several such new technologies with scCO2 and CXLs, which have the capacity to prepare polymeric nanoporous materials with unique morphologies. The fabricated nanoporous polymers have significantly improved the performance of polymeric monoliths and films, and have found wide applications as templates, antireflection coatings, low-k materials, tissue engineering scaffolds and filtration membranes. This tutorial review also introduces the associated characterization methods, including the imaging, scattering and physisorption techniques.

  5. Sensitivity of simulated CO2 concentration to regridding of global fossil fuel CO2 emissions

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Gurney, K. R.; Rayner, P.; Liu, Y.; Asefi-Najafabady, S.

    2014-12-01

    Errors in the specification or utilization of fossil fuel CO2 emissions within carbon budget or atmospheric CO2 inverse studies can alias the estimation of biospheric and oceanic carbon exchange. A key component in the simulation of CO2 concentrations arising from fossil fuel emissions is the spatial distribution of the emission near coastlines. Regridding of fossil fuel CO2 emissions (FFCO2) from fine to coarse grids to enable atmospheric transport simulations can give rise to mismatches between the emissions and simulated atmospheric dynamics which differ over land or water. For example, emissions originally emanating from the land are emitted from a grid cell for which the vertical mixing reflects the roughness and/or surface energy exchange of an ocean surface. We test this potential "dynamical inconsistency" by examining simulated global atmospheric CO2 concentration driven by two different approaches to regridding fossil fuel CO2 emissions. The two approaches are as follows: (1) a commonly used method that allocates emissions to grid cells with no attempt to ensure dynamical consistency with atmospheric transport and (2) an improved method that reallocates emissions to grid cells to ensure dynamically consistent results. Results show large spatial and temporal differences in the simulated CO2 concentration when comparing these two approaches. The emissions difference ranges from -30.3 TgC grid cell-1 yr-1 (-3.39 kgC m-2 yr-1) to +30.0 TgC grid cell-1 yr-1 (+2.6 kgC m-2 yr-1) along coastal margins. Maximum simulated annual mean CO2 concentration differences at the surface exceed ±6 ppm at various locations and times. Examination of the current CO2 monitoring locations during the local afternoon, consistent with inversion modeling system sampling and measurement protocols, finds maximum hourly differences at 38 stations exceed ±0.10 ppm with individual station differences exceeding -32 ppm. The differences implied by not accounting for this dynamical

  6. Anthropogenic point and area source CO2 plume measurements: Implications for spaceborne CO2 sensor design

    NASA Astrophysics Data System (ADS)

    Andrews, A. E.; Ryerson, T. B.; Peischl, J.; Parrish, D. D.; Trainer, M.; Tans, P. P.

    2011-12-01

    Anthropogenic point and area source CO2 plume measurements: Implications for spaceborne CO2 sensor design A. Andrews, T. Ryerson, J. Peischl, D. Parrish, M. Trainer, P. Tans An extensive dataset of CO2 concentrations including enhancements in point and area source plumes is available from in situ measurements collected using the NOAA P-3 and NCAR Electra research aircraft during seven major field projects from 1999 through 2010. Research flights sampled emission plumes from coal-, oil-, and natural gas-fired electric utility power plants, industrial facilities, and urban areas. Plume sampling often included horizontal transects at several altitudes and multiple distances downwind. CO2 data from crosswind transects upwind and downwind, coupled with ancillary measurements of co-emitted nitric oxide, nitrogen dioxide and sulfur dioxide, along with plume location, and wind speed and direction permit unambiguous attribution and quantification of atmospheric plumes from individual sources. Certain point sources were revisited on multiple flights over the course of 1-2 month long field projects and on successive field projects spanning several years. Sampling occurred primarily in the summertime, daytime continental boundary layer, with some plume studies performed after dark and in the spring, fall, and winter seasons. The data provide rigorously calibrated, measurement-based constraints on the expected range of atmospheric CO2 plume enhancements that can be used to assess satellite sensor concepts. Crosswind near-field (~5 km) transects in the summer daytime mixed-layer downwind of the strongest point sources were characterized by peak plume CO2 mixing ratio enhancements >100 ppm above background for the 100-m spatial averages reported from the moving aircraft. On many flights, the aircraft tracked such emissions plumes beyond 150 km downwind, or up to 10 hours of transport time, until plume enhancements were indistinguishable from background variability in CO2

  7. Impact of CO2 Impure stream on a CO2 Storage Reservoir

    NASA Astrophysics Data System (ADS)

    Segev, R.; Bear, J.; Bensabat, J.

    2013-12-01

    In a CO2 capture and storage (CCS) technology, a stream of CO2, extracted from the gas stream emitted from an industrial plant, is transported to a storage site where it is injected into a deep brine-containing geological reservoir for storage for very long time periods. The injected CO2 may contain various compositions of residual O2, SOx , NOx, and inert gases. In this work, we focus on the impact of the SO2 and its potential to acidify the reservoir brine. The amount of dissolved SO2 is determined by adjusting the Henry coefficient and fugacity coefficient for the mixture that contains CO2 as a major component and SO2. The models show the spreading of the pH level over time in the entire reservoir when different CO2-SO2 mixture compositions are injected. The minimum pH level achieved is 0.35 when 4% SO2 is injected, 1.8 when 2% SO2 is injected and 3.8 when a pure CO2 stream is injected. The model may serve as a tool to predict the influence of SO2 on the initial brine composition and on the initial rock properties. For example, a model result for the pH spreading in the reservoir, in the case of 2%SO2-CO2 injected mixture, is shown below. Fig.1. The pH level at the reservoir bedrock and caprock after 5 years for a 2%SO2-CO2 stream.

  8. CO2 emission estimation in the urban environment: Measurement of the CO2 storage term

    NASA Astrophysics Data System (ADS)

    Bjorkegren, A. B.; Grimmond, C. S. B.; Kotthaus, S.; Malamud, B. D.

    2015-12-01

    Eddy covariance has been used in urban areas to evaluate the net exchange of CO2 between the surface and the atmosphere. Typically, only the vertical flux is measured at a height 2-3 times that of the local roughness elements; however, under conditions of relatively low instability, CO2 may accumulate in the airspace below the measurement height. This can result in inaccurate emissions estimates if the accumulated CO2 drains away or is flushed upwards during thermal expansion of the boundary layer. Some studies apply a single height storage correction; however, this requires the assumption that the response of the CO2 concentration profile to forcing is constant with height. Here a full seasonal cycle (7th June 2012 to 3rd June 2013) of single height CO2 storage data calculated from concentrations measured at 10 Hz by open path gas analyser are compared to a data set calculated from a concurrent switched vertical profile measured (2 Hz, closed path gas analyser) at 10 heights within and above a street canyon in central London. The assumption required for the former storage determination is shown to be invalid. For approximately regular street canyons at least one other measurement is required. Continuous measurements at fewer locations are shown to be preferable to a spatially dense, switched profile, as temporal interpolation is ineffective. The majority of the spectral energy of the CO2 storage time series was found to be between 0.001 and 0.2 Hz (500 and 5 s respectively); however, sampling frequencies of 2 Hz and below still result in significantly lower CO2 storage values. An empirical method of correcting CO2 storage values from under-sampled time series is proposed.

  9. TES/Aura L2 Carbon Dioxide (CO2) Nadir (TL2CO2NS)

    Atmospheric Science Data Center

    2017-02-27

    TES/Aura L2 Carbon Dioxide (CO2) Nadir (TL2CO2NS) News:  TES News ... Level:  L2 Platform:  TES/Aura L2 Carbon Dioxide Spatial Coverage:  5.3 x 8.5 km nadir ... Data: TES Order Tool Parameters:  Carbon Dioxide Order Data:  Search and Order:   Earthdata ...

  10. TES/Aura L2 Carbon Dioxide (CO2) Nadir (TL2CO2N)

    Atmospheric Science Data Center

    2017-02-27

    TES/Aura L2 Carbon Dioxide (CO2) Nadir (TL2CO2N) News:  TES News ... Level:  L2 Platform:  TES/Aura L2 Carbon Dioxide Spatial Coverage:  5.2 x 8.5 km nadir ... Data: TES Order Tool Parameters:  Carbon Dioxide Order Data:  Search and Order:   Earthdata ...

  11. Infrared spectroscopy of Mg-CO2 and Al-CO2 complexes in helium nanodroplets.

    PubMed

    Thomas, Brandon J; Harruff-Miller, Barbara A; Bunker, Christopher E; Lewis, William K

    2015-05-07

    The catalytic reduction of CO2 to produce hydrocarbon fuels is a topic that has gained significant attention. Development of efficient catalysts is a key enabler to such approaches, and metal-based catalysts have shown promise towards this goal. The development of a fundamental understanding of the interactions between CO2 molecules and metal atoms is expected to offer insight into the chemistry that occurs at the active site of such catalysts. In the current study, we utilize helium droplet methods to assemble complexes composed of a CO2 molecule and a Mg or Al atom. High-resolution infrared (IR) spectroscopy and optically selected mass spectrometry are used to probe the structure and binding of the complexes, and the experimental observations are compared with theoretical results determined from ab initio calculations. In both the Mg-CO2 and Al-CO2 systems, two IR bands are obtained: one assigned to a linear isomer and the other assigned to a T-shaped isomer. In the case of the Mg-CO2 complexes, the vibrational frequencies and rotational constants associated with the two isomers are in good agreement with theoretical values. In the case of the Al-CO2 complexes, the vibrational frequencies agree with theoretical predictions; however, the bands from both structural isomers exhibit significant homogeneous broadening sufficient to completely obscure the rotational structure of the bands. The broadening is consistent with an upper state lifetime of 2.7 ps for the linear isomer and 1.8 ps for the T-shaped isomer. The short lifetime is tentatively attributed to a prompt photo-induced chemical reaction between the CO2 molecule and the Al atom comprising the complex.

  12. CO2 Sequestration within Spent Oil Shale

    NASA Astrophysics Data System (ADS)

    Foster, H.; Worrall, F.; Gluyas, J.; Morgan, C.; Fraser, J.

    2013-12-01

    Worldwide deposits of oil shales are thought to represent ~3 trillion barrels of oil. Jordanian oil shale deposits are extensive and of high quality, and could represent 100 billion barrels of oil, leading to much interest and activity in the development of these deposits. The exploitation of oil shales has raised a number of environmental concerns including: land use, waste disposal, water consumption, and greenhouse gas emissions. The dry retorting of oil shales can overcome a number of the environmental impacts, but this leaves concerns over management of spent oil shale and CO2 production. In this study we propose that the spent oil shale can be used to sequester CO2 from the retorting process. Here we show that by conducting experiments using high pressure reaction facilities, we can achieve successful carbonation of spent oil shale. High pressure reactor facilities in the Department of Earth Sciences, Durham University, are capable of reacting solids with a range of fluids up to 15 MPa and 350°C, being specially designed for research with supercritical fluids. Jordanian spent oil shale was reacted with high pressure CO2 in order to assess whether there is potential for sequestration. Fresh and reacted materials were then examined by: Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Thermogravimetric Analysis (TGA), X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD) methods. Jordanian spent oil shale was found to sequester up to 5.8 wt % CO2, on reacting under supercritical conditions, which is 90% of the theoretical carbonation. Jordanian spent oil shale is composed of a large proportion of CaCO3, which on retorting decomposes, forming CaSO4 and Ca-oxides which are the focus of carbonation reactions. A factorially designed experiment was used to test different factors on the extent of carbonation, including: pressure; temperature; duration; and the water content. Analysis of Variance (ANOVA) techniques were then used to determine the significance of

  13. 46 CFR 108.433 - Quantity of CO2: General.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Quantity of CO2: General. 108.433 Section 108.433... Quantity of CO2: General. Each CO2 system must have enough gas to meet the quantity requirements of § 108.439 for the space requiring the greatest amount of CO2....

  14. 46 CFR 108.433 - Quantity of CO2: General.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Quantity of CO2: General. 108.433 Section 108.433... Quantity of CO2: General. Each CO2 system must have enough gas to meet the quantity requirements of § 108.439 for the space requiring the greatest amount of CO2....

  15. 40 CFR 98.473 - Calculating CO2 received.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... received in metric tons by multiplying the mass flow by the CO2 concentration in the flow, according to... = Quarterly CO2 concentration measurement in flow for flow meter r in quarter p (wt. percent CO2, expressed as... multiplying the volumetric flow at standard conditions by the CO2 concentration in the flow and the density...

  16. 40 CFR 98.423 - Calculating CO2 supply.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... as allowed in paragraph (b) of this section, calculate the annual mass of CO2 captured, extracted... mass of CO2 for all flow meters according to the procedures specified in paragraph (a)(3) of this section. (1) For each mass flow meter, you shall calculate quarterly the mass of CO2 in a CO2 stream in...

  17. Uncertainty analyses of CO2 plume expansion subsequent to wellbore CO2 leakage into aquifers

    SciTech Connect

    Hou, Zhangshuan; Bacon, Diana H.; Engel, David W.; Lin, Guang; Fang, Yilin; Ren, Huiying; Fang, Zhufeng

    2014-08-01

    In this study, we apply an uncertainty quantification (UQ) framework to CO2 sequestration problems. In one scenario, we look at the risk of wellbore leakage of CO2 into a shallow unconfined aquifer in an urban area; in another scenario, we study the effects of reservoir heterogeneity on CO2 migration. We combine various sampling approaches (quasi-Monte Carlo, probabilistic collocation, and adaptive sampling) in order to reduce the number of forward calculations while trying to fully explore the input parameter space and quantify the input uncertainty. The CO2 migration is simulated using the PNNL-developed simulator STOMP-CO2e (the water-salt-CO2 module). For computationally demanding simulations with 3D heterogeneity fields, we combined the framework with a scalable version module, eSTOMP, as the forward modeling simulator. We built response curves and response surfaces of model outputs with respect to input parameters, to look at the individual and combined effects, and identify and rank the significance of the input parameters.

  18. CO2 transport in normovolemic anemia: complete compensation and stability of blood CO2 tensions.

    PubMed

    Deem, S; Alberts, M K; Bishop, M J; Bidani, A; Swenson, E R

    1997-07-01

    Isovolemic hemodilution does not appear to impair CO2 elimination nor cause CO2 retention despite the important role of red blood cells in blood CO2 transport. We studied this phenomenon and its physiological basis in eight New Zealand White rabbits that were anesthetized, paralyzed, and mechanically ventilated at a fixed minute ventilation. Isovolemic anemia was induced by simultaneous blood withdrawal and infusion of 6% hetastarch in sequential stages; exchange transfusions ranged from 15-30 ml in volume. Variables measured after each hemodilution included hematocrit (Hct), arterial and venous blood gases, mixed expired PCO2 and PO2, and blood pressure; also, O2 consumption, CO2 production, cardiac output (Q), and physiological dead space were calculated. Data were analyzed by comparison of changes in variables with changes in Hct and by using the model of capillary gas exchange described by Bidani (J. Appl. Physiol. 70: 1686-1699, 1991). There was complete compensation for anemia with stability of venous and arterial PCO2 between Hct values of 36 +/- 3 and 12 +/- 1%, which was predicted by the mathematical model. Over this range of hemodilution, Q rose 50%, and the O2 extraction ratio increased 61% without a decline in CO2 production or a rise in alveolar ventilation. The dominant compensations maintaining CO2 transport in normovolemic anemia include an increased Q and an augmented Haldane effect arising from the accompanying greater O2 extraction.

  19. Low pCO2 Air-Polarized CO2 Concentrator Development

    NASA Technical Reports Server (NTRS)

    Schubert, Franz H.

    1997-01-01

    Life Systems completed a Ground-based Space Station Experiment Development Study Program which verifies through testing the performance and applicability of the electrochemical Air-Polarized Carbon Dioxide Concentrator (APC) process technology for space missions requiring low (i.e., less than 3 mm Hg) CO2 partial pressure (pCO2) in the cabin atmosphere. Required test hardware was developed and testing was accomplished at an approximate one-person capacity CO2 removal level. Initially, two five-cell electrochemical modules using flight-like 0.5 sq ft cell hardware were tested individually, following by their testing at the integrated APC system level. Testing verified previously projected performance and established a database for sizing of APC systems. A four person capacity APC system was sized and compared with four candidate CO2 removal systems. At its weight of 252 lb, a volume of 7 cu ft and a power consumption of 566 W while operating at 2.2 mm Hg pCO2, the APC was surpassed only by an Electrochemical Depolarized CO2 Concentrator (EDC) (operating with H2), when compared on a total equivalent basis.

  20. Coherent laser radar: Current European systems

    NASA Technical Reports Server (NTRS)

    Vaughan, J. Michael

    1985-01-01

    Coherent laser radar systems at 10 micrometers have been studied in Europe for well over a decade. In the past few years, the level of activity has increased rapidly and work is now in progress on systems and components at a large number of research institutions and industrial firms. Some of the organizations have had specific involvement with wind and aerosol measuring lidars, while others are largely concerned with components. Some of the particular European strong points are reviewed in device physics and technology. In addition to wind measurement systems, much work has been done on other applications of coherent laser radar including ranging, imaging, and coherent DIAL studies. Some of these other applications are also outlined.

  1. Effective Use of Natural CO2-RICH Systems for Stakeholder Communication: CO2FACTS.ORG

    NASA Astrophysics Data System (ADS)

    Olson, H. C.; Romanak, K.; Osborne, V.; Hovorka, S. D.; Clift, S.; Castner, A.

    2011-12-01

    The impact of using natural analogues as an avenue for communicating about CO2 injection and storage technology with stakeholders has been addressed by previous researchers, e.g., Romanak et al (2011), Dixon et al (2011). Analogies between natural CO2-rich systems and engineered CO2 storage are not necessarily straightforward, and stakeholder opinion is often based on factors other than technical accuracy of information (e.g., lack of trust, confidence, and fear). In order to enhance this communication pathway, STORE (Sequestration Training, Outreach, Research and Education), the outreach arm of the Gulf Coast Carbon Center at The University of Texas at Austin, has created an online resource (www.co2facts.org) to help stakeholders better understand the injection and storage of CO2 underground. The online resource includes frequently asked questions (FAQs) for a variety of CO2-storage-related issues, including those related to natural analogues, and uses examples of natural systems of CO2 release for communication. The content targets various levels of technical education and understanding. A unique feature of the online resource is its approach to verification of information. Each FAQ and example is "fact-checked" by an actual expert in the field. Part of this verification process is to provide an online link to background, credentials, scientific research and images of actual experts in the field at natural release sites. This approach helps put a face to, and potentially builds a relationship of trust with, the scientist behind the technical information. Videos of experts discussing natural systems and their similarities and differences with CO2 injection and storage sites are also part of the resource. Stakeholders commonly draw incorrect parallels between natural disasters that gain attention in the media (e.g., Lake Nyos) and CO2 injection and storage technology. The video images available at www.co2facts.org are a useful tool for assuaging environmental fears

  2. The Werkendam natural CO2 accumulation: An analogue for CO2 storage in depleted oil reservoirs

    NASA Astrophysics Data System (ADS)

    Bertier, Pieter; Busch, Andreas; Hangx, Suzanne; Kampman, Niko; Nover, Georg; Stanjek, Helge; Weniger, Philipp

    2015-04-01

    The Werkendam natural CO2 accumulation is hosted in the Röt (Early Triassic) sandstone of the West Netherlands Basin, at a depth of 2.8 km, about 20 km south-east of Rotterdam (NL). This reservoir, in a fault-bound structure, was oil-filled prior to charging with magmatic CO2 in the early Cretaceous. It therefore offers a unique opportunity to study long-term CO2-water-rock interactions in the presence of oil. This contribution will present the results of a detailed mineralogical and geochemical characterisation of core sections from the Werkendam CO2 reservoir and an adjacent, stratigraphically equivalent aquifer. X-ray diffraction combined with X-ray fluorescence spectrometry revealed that the reservoir samples contain substantially more feldspar and more barite and siderite than those from the aquifer, while the latter have higher hematite contents. These differences are attributed to the effects hydrocarbons and related fluids on diagenesis in the closed system of the CO2 reservoir versus the open-system of the aquifer. Petrophysical analyses yielded overall higher and more anisotropic permeability for the reservoir samples, while the porosity is overall not significantly different from that of their aquifer equivalents. The differences are most pronounced in coarse-grained sandstones. These have low anhydrite contents and contain traces of calcite, while all other analyzed samples contain abundant anhydrite, dolomite/ankerite and siderite, but no calcite. Detailed petrography revealed mm-sized zones of excessive primary porosity. These are attributed to CO2-induced dissolution of precompactional, grain-replacive anhydrite cement. Diagenetic dolomite/ankerite crystals are covered by anhedral, epitaxial ankerite, separated from the crystals by bitumen coats. Since these carbonates were oil-wet before CO2-charging, the overgrowths are interpreted to have grown after CO2-charging. Their anhedral habit suggests growth in a 2-phase water-CO2 system. Isotopic

  3. Method for tracing simulated CO2 leak in terrestrial environment with a 13CO2 tracer

    NASA Astrophysics Data System (ADS)

    Moni, Christophe; Rasse, Daniel

    2013-04-01

    Facilities for the geological storage of carbon dioxide (CO2) as part of carbon capture and storage (CCS) schemes will be designed to prevent any leakage from the defined 'storage complex'. However, developing regulations and guidance throughout the world (e.g. the EC Directive and the USEPA Vulnerability Evaluation Framework) recognize the importance of assessing the potential for environmental impacts from CO2 storage. RISCS, a European (FP7) project, aims to improve understanding of those impacts that could plausibly occur in the hypothetical case that unexpected leakage occurs. As part of the RISCS project the potential impacts that an unexpected CO2 leaks might have on a cropland ecosystems was investigated. A CO2 exposure field experiment based on CO2 injection at 85 cm depth under an oats culture was designed. To facilitate the characterization of the simulated leaking zone the gas used for injection was produced from natural gas and had a δ13C of -46‰. The aim of the present communication is to depict how the injected gas was traced within the soil-vegetation-atmosphere continuum using 13CO2 continuous cavity ring-down spectrometry (CRDS). Four subsurface experimental injection plots (6m x 3m) were set up. In order to test the effects of different intensity of leakage, the field experiment was designed as to create a longitudinal CO2 gradient for each plot. For this purpose gas supply pipes were inserted at one extremity of each plot at the base of a 45 cm thick layer of sand buried 40 cm below the surface under the clayey plough layer of Norwegian moraine soils. Soil CO2 concentration and isotopic signature were punctually recorded: 1) in the soil at 20 cm depth at 6 positions distributed on the central transect, 2) at the surface following a (50x50 cm) grid sampling pattern, and 3) in the canopy atmosphere at 10, 20, 30 cm along three longitudinal transects (seven sampling point per transect). Soil CO2 fluxes and isotopic signature were finally

  4. Mechanisms of CO2 Capture into Monoethanolamine Solution with Different CO2 Loading during the Absorption/Desorption Processes.

    PubMed

    Lv, Bihong; Guo, Bingsong; Zhou, Zuoming; Jing, Guohua

    2015-09-01

    Though the mechanism of MEA-CO2 system has been widely studied, there is few literature on the detailed mechanism of CO2 capture into MEA solution with different CO2 loading during absorption/desorption processes. To get a clear picture of the process mechanism, (13)C nuclear magnetic resonance (NMR) was used to analyze the reaction intermediates under different CO2 loadings and detailed mechanism on CO2 absorption and desorption in MEA was evaluated in this work. The results demonstrated that the CO2 absorption in MEA started with the formation of carbamate according to the zwitterion mechanism, followed by the hydration of CO2 to form HCO3(-)/CO3(2-), and accompanied by the hydrolysis of carbamate. It is interesting to find that the existence of carbamate will be influenced by CO2 loading and that it is rather unstable at high CO2 loading. At low CO2 loading, carbamate is formed fast by the reaction between CO2 and MEA. At high CO2 loading, it is formed by the reaction of CO3(-)/CO3(2-) with MEA, and the formed carbamate can be easily hydrolyzed by H(+). Moreover, CO2 desorption from the CO2-saturated MEA solution was proved to be a reverse process of absorption. Initially, some HCO3(-) were heated to release CO2 and other HCO3(-) were reacted with carbamic acid (MEAH(+)) to form carbamate, and the carbamate was then decomposed to MEA and CO2.

  5. Effects of atmospheric CO2 enrichment on soil CO2 efflux in a young longleaf pine system

    USDA-ARS?s Scientific Manuscript database

    Elevated atmospheric carbon dioxide (CO2) can affect the quantity and quality of plant tissues which will impact carbon (C) cycling and storage in plant/soil systems and the release of CO2 back to the atmosphere. Research is needed to quantify the effects of elevated CO2 on soil CO2 efflux to predi...

  6. Measurements of fugitive hydrocarbon emissions with a tunable infrared DIAL

    NASA Technical Reports Server (NTRS)

    Milton, M. J. T.; Woods, P. T.; Jolliffe, B. W.; Swann, N. R. W.; Robinson, R. A.

    1992-01-01

    A tunable infrared differential absorption lidar (DIAL) system has been designed and developed at the National Physics Lab (NPL) which is capable of making measurements throughout the spectral region 3.0 to 4.2 micro-m. It is ideally suited to measuring a range of organic and inorganic species including methane, propane, and butane. The system also has an ultraviolet channel that is capable of making simultaneous measurements of aromatic hydrocarbons such as Toluene and benzene. This paper describes the source and detection system, together with some measurements of fugitive hydrocarbon emissions performed at various petrochemical plants.

  7. Raman-shifted dye laser for water vapor DIAL measurements

    NASA Technical Reports Server (NTRS)

    Grossmann, B. E.; Singh, U. N.; Cotnoir, L. J.; Wilkerson, T. D.; Higdon, N. S.; Browell, E. V.

    1987-01-01

    For improved DIAL measurements of water vapor in the upper troposphere or lower stratosphere, narrowband (about 0.03/cm) laser radiation at 720- and 940-nm wavelengths was generated by stimulated Raman scattering (SRS), using the narrow linewidth (about 0.02/cm) output of a Nd:YAG-pumped dye laser. For a hydrogen pressure of 350 psi, the first Stokes conversion efficiencies to 940 nm were 20 percent and 35 percent, when using a conventional and waveguide Raman cell, respectively. The linewidth of the first Stokes line at high cell pressures, and the inferred collisional broadening coefficients, agree well with those previously measured in spontaneous Raman scattering.

  8. Measurements of fugitive hydrocarbon emissions with a tunable infrared DIAL

    NASA Technical Reports Server (NTRS)

    Milton, M. J. T.; Woods, P. T.; Jolliffe, B. W.; Swann, N. R. W.; Robinson, R. A.

    1992-01-01

    A tunable infrared differential absorption lidar (DIAL) system has been designed and developed at the National Physics Lab (NPL) which is capable of making measurements throughout the spectral region 3.0 to 4.2 micro-m. It is ideally suited to measuring a range of organic and inorganic species including methane, propane, and butane. The system also has an ultraviolet channel that is capable of making simultaneous measurements of aromatic hydrocarbons such as Toluene and benzene. This paper describes the source and detection system, together with some measurements of fugitive hydrocarbon emissions performed at various petrochemical plants.

  9. Raman-shifted dye laser for water vapor DIAL measurements

    NASA Technical Reports Server (NTRS)

    Grossmann, B. E.; Singh, U. N.; Cotnoir, L. J.; Wilkerson, T. D.; Higdon, N. S.; Browell, E. V.

    1987-01-01

    For improved DIAL measurements of water vapor in the upper troposphere or lower stratosphere, narrowband (about 0.03/cm) laser radiation at 720- and 940-nm wavelengths was generated by stimulated Raman scattering (SRS), using the narrow linewidth (about 0.02/cm) output of a Nd:YAG-pumped dye laser. For a hydrogen pressure of 350 psi, the first Stokes conversion efficiencies to 940 nm were 20 percent and 35 percent, when using a conventional and waveguide Raman cell, respectively. The linewidth of the first Stokes line at high cell pressures, and the inferred collisional broadening coefficients, agree well with those previously measured in spontaneous Raman scattering.

  10. The role of CO2 decline for the onset of Northern Hemisphere glaciation

    NASA Astrophysics Data System (ADS)

    Willeit, Matteo; Ganopolski, Andrey; Calov, Reinhard; Robinson, Alexander; Maslin, Mark

    2015-07-01

    The Pliocene-Pleistocene Transition (PPT), from around 3.2 to 2.5 million years ago (Ma), represented a major shift in the climate system and was characterized by a gradual cooling trend and the appearance of large continental ice sheets over northern Eurasia and North America. Paleo evidence indicates that the PPT was accompanied and possibly caused by a decrease in atmospheric CO2, but the temporal resolution of CO2 reconstructions is low for this period of time and uncertainties remain large. Therefore, instead of applying existent CO2 reconstructions we solved an 'inverse' problem by finding a schematic CO2 concentration scenario that allows us to simulate the temporal evolution of key climate characteristics in agreement with paleoclimate records. To this end, we performed an ensemble of transient simulations with an Earth system model of intermediate complexity from which we derived a best guess transient CO2 scenario for the interval from 3.2 to 2.4 Ma that gives the best fit between the simulated and reconstructed benthic δ18O and global sea surface temperature evolution. Our data-constrained CO2 scenarios are consistent with recent CO2 reconstructions and suggest a gradual CO2 decline from 375-425 to 275-300 ppm, between 3.2 and 2.4 Ma. In addition to a gradual decline, the best fit to paleoclimate data requires the existence of pronounced CO2 variability coherent with the 41-kyr (1 kyr = 1000 years) obliquity cycle. In our simulations the long-term CO2 decline is accompanied by a relatively abrupt intensification of Northern Hemisphere glaciation at around 2.7 Ma. This is the result of a threshold behaviour of the ice sheets response to gradual CO2 decrease and orbital forcing. The simulated Northern Hemisphere ice sheets during the early Pleistocene glacial cycles reach a maximum volume equivalent to a sea level drop of about 40 m. Both ice volume and benthic δ18O are dominated by 41-kyr cyclicity. Our simulations suggest that before 2.7 Ma Greenland

  11. PLAINS CO2 REDUCTION (PCOR) PARTNERSHIP

    SciTech Connect

    Edward N. Steadman; Daniel J. Daly; Lynette L. de Silva; John A. Harju; Melanie D. Jensen; Erin M. O'Leary; Wesley D. Peck; Steven A. Smith; James A. Sorensen

    2006-01-01

    During the period of October 1, 2003, through September 30, 2005, the Plains CO2 Reduction (PCOR) Partnership, identified geologic and terrestrial candidates for near-term practical and environmentally sound carbon dioxide (CO2) sequestration demonstrations in the heartland of North America. The PCOR Partnership region covered nine states and three Canadian provinces. The validation test candidates were further vetted to ensure that they represented projects with (1) commercial potential and (2) a mix that would support future projects both dependent and independent of CO2 monetization. This report uses the findings contained in the PCOR Partnership's two dozen topical reports and half-dozen fact sheets as well as the capabilities of its geographic information system-based Decision Support System to provide a concise picture of the sequestration potential for both terrestrial and geologic sequestration in the PCOR Partnership region based on assessments of sources, sinks, regulations, deployment issues, transportation, and capture and separation. The report also includes concise action plans for deployment and public education and outreach as well as a brief overview of the structure, development, and capabilities of the PCOR Partnership. The PCOR Partnership is one of seven regional partnerships under Phase I of the U.S. Department of Energy National Energy Technology Laboratory's Regional Carbon Sequestration Partnership program. The PCOR Partnership, comprising 49 public and private sector members, is led by the Energy & Environmental Research Center at the University of North Dakota. The international PCOR Partnership region includes the Canadian provinces of Alberta, Saskatchewan, and Manitoba and the states of Montana (part), Wyoming (part), North Dakota, South Dakota, Nebraska, Missouri, Iowa, Minnesota, and Wisconsin.

  12. Anthropogenic CO2 emissions in Africa

    NASA Astrophysics Data System (ADS)

    Canadell, J. G.; Raupach, M. R.; Houghton, R. A.

    2008-11-01

    An understanding of the regional contributions and trends of anthropogenic carbon dioxide (CO2) emissions is critical to design mitigation strategies aimed at stabilizing atmospheric greenhouse gases. Here we report CO2 emissions from the combustion of fossil fuels and land use change in Africa for various time periods. Africa was responsible for an average of 500 TgC y-1 for the period 2000 2005. These emissions resulted from the combustion of fossil fuels (260 TgC y-1) and land use change (240 TgC y-1). Over this period, the African share of global emissions from land use change was 17%. For 2005, the last year reported in this study, African fossil fuel emissions were 285 TgC accounting for 3.7% of the global emissions. The 2000 2005 growth rate in African fossil fuel emissions was 3.2% y-1, very close to the global average. Fossil fuel emissions per capita in Africa are among the lowest in the world, at 0.32 tC y-1 compared to the global average of 1.2 tC y-1. The average amount of carbon (C) emitted as CO2 to produce 1 US of Gross Domestic Product (GDP) in Africa in 2005 was 187 gC/, close to the world average of 199 gC/. With the fastest population growth in the world and rising per capita GDP, Africa is likely to increase its share of global emissions over the coming decades although emissions from Africa will remain low compared to other continents.

  13. Anthropogenic CO2 emissions in Africa

    NASA Astrophysics Data System (ADS)

    Canadell, J. G.; Raupach, M. R.; Houghton, R. A.

    2009-03-01

    An understanding of the regional contributions and trends of anthropogenic carbon dioxide (CO2) emissions is critical to design mitigation strategies aimed at stabilizing atmospheric greenhouse gases. Here we report CO2 emissions from the combustion of fossil fuels and land use change in Africa for various time periods. Africa was responsible for an average of 500 Tg C y-1 for the period 2000-2005. These emissions resulted from the combustion of fossil fuels (260 Tg C y-1) and land use change (240 Tg C y-1). Over this period, the African share of global emissions from land use change was 17%. For 2005, the last year reported in this study, African fossil fuel emissions were 285 Tg C accounting for 3.7% of the global emissions. The 2000-2005 growth rate in African fossil fuel emissions was 3.2% y-1, very close to the global average. Fossil fuel emissions per capita in Africa are among the lowest in the world, at 0.32 t C y-1 compared to the global average of 1.2 t C y-1. The average amount of carbon (C) emitted as CO2 to produce 1 US{} of Gross Domestic Product (GDP) in Africa was 187 g C/ in 2005, close to the world average of 199 g C/. With the fastest population growth in the world and rising per capita GDP, Africa is likely to increase its share of global emissions over the coming decades although emissions from Africa will remain low compared to other continents.

  14. Saturated CO2 inhibits microbial processes in CO2-vented deep-sea sediments

    NASA Astrophysics Data System (ADS)

    de Beer, D.; Haeckel, M.; Neumann, J.; Wegener, G.; Inagaki, F.; Boetius, A.

    2013-08-01

    This study focused on biogeochemical processes and microbial activity in sediments of a natural deep-sea CO2 seepage area (Yonaguni Knoll IV hydrothermal system, Japan). The aim was to assess the influence of the geochemical conditions occurring in highly acidic and CO2 saturated sediments on sulfate reduction (SR) and anaerobic methane oxidation (AOM). Porewater chemistry was investigated from retrieved sediment cores and in situ by microsensor profiling. The sites sampled around a sediment-hosted hydrothermal CO2 vent were very heterogeneous in porewater chemistry, indicating a complex leakage pattern. Near the vents, droplets of liquid CO2 were observed emanating from the sediments, and the pH reached approximately 4.5 in a sediment depth > 6 cm, as determined in situ by microsensors. Methane and sulfate co-occurred in most sediment samples from the vicinity of the vents down to a depth of 3 m. However, SR and AOM were restricted to the upper 7-15 cm below seafloor, although neither temperature, low pH, nor the availability of methane and sulfate could be limiting microbial activity. We argue that the extremely high subsurface concentrations of dissolved CO2 (1000-1700 mM), which disrupt the cellular pH homeostasis, and lead to end-product inhibition. This limits life to the surface sediment horizons above the liquid CO2 phase, where less extreme conditions prevail. Our results may have to be taken into consideration in assessing the consequences of deep-sea CO2 sequestration on benthic element cycling and on the local ecosystem state.

  15. Atmospheric CO2 from fossil plant cuticles.

    PubMed

    Kerp, Hans

    2002-01-03

    Plants respond to changes in atmospheric carbon dioxide levels by regulating the number of stomata in their leaves. In his reconstruction of a continuous, 300-million-year record of atmospheric CO2, Retallack bases his curve on stomatal counts of fossil plant cuticles taken from published micrographs. However, the preservation of cuticles from Permian times is generally too fragmentary for the stomatal index to be reliably determined, the micrographs used could have biased the results, and there are important errors in the supplementary data - all of which cast doubt on the Permian part of Retallack's record.

  16. Recent advances in CO2 laser catalysts

    NASA Technical Reports Server (NTRS)

    Upchurch, B. T.; Schryer, D. R.; Brown, K. G.; Kielin, E. J.; Hoflund, G. B.; Gardner, S. D.

    1991-01-01

    This paper discusses several recent advances in CO2 laser catalysts including comparisons of the activity of Au/MnO2 to Pt/SnO2 catalysts with possible explanations for observed differences. The catalysts are compared for the effect of test gas composition, pretreatment temperature, isotopic integrity, long term activity, and gold loading effects on the Au/MnO2 catalyst activity. Tests conducted to date include both long-term tests of up to six months continuous operation and short-term tests of one week or more that include isotopic integrity testing.

  17. CO2 laser ranging systems study

    NASA Technical Reports Server (NTRS)

    Filippi, C. A.

    1975-01-01

    The conceptual design and error performance of a CO2 laser ranging system are analyzed. Ranging signal and subsystem processing alternatives are identified, and their comprehensive evaluation yields preferred candidate solutions which are analyzed to derive range and range rate error contributions. The performance results are presented in the form of extensive tables and figures which identify the ranging accuracy compromises as a function of the key system design parameters and subsystem performance indexes. The ranging errors obtained are noted to be within the high accuracy requirements of existing NASA/GSFC missions with a proper system design.

  18. [CO(2) laser treatment of sialolithiasis].

    PubMed

    López Alvarez-Buhilla, P; Blanco Bruned, J L; Torres Piedra, C; Alfonso Sánchez, L

    2000-07-01

    Sialolithiasis of the submaxillary gland is rare in the pediatric population. We report the case of a 13-year-old boy who presented submandibular tumefaction of 7 months evolution, which increased after meals. Localized lithiasis in Wharton s duct was observed in submaxillary sialolithiasis. Treatment was intraoral extraction with CO(2) laser and after recovering from the anesthetic, the patient was discharged.This technique shortens surgical time, facilitates hemostasia and reduces edema and postoperative pain. The procedure is suitable for ambulatory surgery.

  19. Photosynthesis and Growth of Water Hyacinth under CO(2) Enrichment.

    PubMed

    Spencer, W; Bowes, G

    1986-10-01

    Water hyacinth (Eichhornia crassipes [Mart.] Solms) plants were grown in environmental chambers at ambient and enriched CO(2) levels (330 and 600 microliters CO(2) per liter). Daughter plants (ramets) produced in the enriched CO(2) gained 39% greater dry weight than those at ambient CO(2), but the original mother plants did not. The CO(2) enrichment increased the number of leaves per ramet and leaf area index, but did not significantly increase leaf size or the number of ramets formed. Flower production was increased 147%. The elevated CO(2) increased the net photosynthetic rate of the mother plants by 40%, but this was not maintained as the plants acclimated to the higher CO(2) level. After 14 days at the elevated CO(2), leaf resistance increased and transpiration decreased, especially from the adaxial leaf surface. After 4 weeks in elevated as compared to ambient CO(2), ribulose bisphosphate carboxylase activity was 40% less, soluble protein content 49% less, and chlorophyll content 26% less; whereas starch content was 40% greater. Although at a given CO(2) level the enriched CO(2) plants had only half the net photosynthetic rate of their counterparts grown at ambient CO(2), they showed similar internal CO(2) concentrations. This suggested that the decreased supply of CO(2) to the mesophyll, as a result of the increased stomatal resistance, was counterbalanced by a decreased utilization of CO(2). Photorespiration and dark respiration were lower, such that the CO(2) compensation point was not altered. The photosynthetic light and CO(2) saturation points were not greatly changed, nor was the O(2) inhibition of photosynthesis (measured at 330 microliters CO(2) per liter). It appears that with CO(2) enrichment the temporary increase in net photosynthesis produced larger ramets. After acclimation, the greater total ramet leaf area more than compensated for the lower net photosynthetic rate on a unit leaf area basis, and resulted in a sustained improvement in dry

  20. Amplification of multi-gigawatt 3 ps pulses in an atmospheric CO2 laser using ac Stark effect.

    PubMed

    Tochitsky, S Ya; Pigeon, J J; Haberberger, D J; Gong, C; Joshi, C

    2012-06-18

    The 3 ps pulses are amplified to ~20 GW peak power in a TEA CO(2) laser using ac Stark broadening. Demonstration of such broadband coherent amplification of 10 μm pulses opens opportunities for a powerful mid-IR source at a high-repetition rate.

  1. CO2 acclimation impacts leaf isoprene emissions: evidence from past to future CO2 levels

    NASA Astrophysics Data System (ADS)

    de Boer, Hugo; van der Laan, Annick; Dekker, Stefan; Holzinger, Rupert

    2017-04-01

    Isoprene is emitted by many plant species as a side-product of photosynthesis. Once in the atmosphere, isoprene exhibits climate forcing through various feedback mechanisms. In order to quantify the climate feedbacks of biogenic isoprene emission it is crucial to establish how isoprene emissions are effected by plant acclimation to rising atmospheric CO2 levels. A promising development for modelling CO2-induced changes in isoprene emissions is the Leaf-Energetic-Status model (referred to as LES-model hereafter, see Harrison et al., 2013 and Morfopoulos et al., 2014). This model simulates isoprene emissions based on the hypothesis that isoprene biosynthesis depends on the imbalance between the photosynthetic electron supply of reducing power and the electron demands of carbon fixation. The energetic imbalance is critically related to the photosynthetic electron transport capacity (Jmax) and the maximum carboxylation capacity of Rubisco (Vcmax). Here we compare predictions of the LES-model with observed isoprene emission responses of Quercus robur (pedunculate oak) specimen that acclimated to CO2 growth conditions representative of the last glacial, the present and the end of this century (200, 400 and 800 ppm, respectively) for two growing seasons. These plants were grown in walk-in growth chambers with tight control of light, temperature, humidity and CO2 concentrations. Photosynthetic biochemical parameters Vcmax and Jmax were determined with a Licor LI-6400XT photosynthesis system. The relationship between photosynthesis and isoprene emissions was measured by coupling the photosynthesis system with a Proton-Transfer Reaction Time-of-Flight Mass Spectrometer. Our empirical results support the LES-model and show that the fractional allocation of carbon to isoprene biosynthesis is reduced in response to both short-term and long-term CO2 increases. In the short term, an increase in CO2 stimulates photosynthesis through an increase in the leaf interior CO2

  2. Wheat response to CO2 enrichment: CO2 exchanges transpiration and mineral uptakes

    NASA Technical Reports Server (NTRS)

    Andre, M.; Ducloux, H.; Richaud, C.

    1986-01-01

    When simulating canopies planted in varied densities, researchers were able to demonstrate that increase of dry matter production by enhancing CO2 quickly becomes independant of increase of leaf area, especially above leaf area index of 2; dry matter gain results mainly from photosynthesis stimulation per unit of surface (primary CO2 effect). When crop density is low (the plants remaining alone a longer time), the effects of increasing leaf surface (tillering, leaf elongation here, branching for other plants etc.) was noticeable and dry matter simulation factor reached 1.65. This area effect decreased when canopy was closed in, as the effect of different surfaces no longer worked. The stimulation of photosynthesis reached to the primary CO2 effect. The accumulation in dry matter which was fast during that phase made the original weight advantage more and more neglectible. Comparison with short term measurements showed that first order long term effect of CO2 in wheat is predictible with short term experiment, from the effect of CO2 on photosynthesis measured on reference sample.

  3. The Field-Laboratory for CO2 Storage 'CO2SINK

    NASA Astrophysics Data System (ADS)

    Würdemann, Hilke; Möller, Fabian; Kühn, Michael; Borm, Günter; Schilling, Frank R.

    2010-05-01

    The first European onshore geological CO2 storage project in a saline aquifer CO2SINK is designed as a field size experiment to better understand in situ storage processes and to test various monitoring techniques. This EU project is run by 18 partners from universities, research institutes and industry out of 9 European countries (www.co2sink.org). The CO2 is injected into Upper Triassic sandstones (Stuttgart Formation) of a double-anticline at a depth of 650 m. The Stuttgart Formation represents a flu vial environment comprised of sandstone channels and silty to muddy deposits. The anticline forms a classical multibarrier system: The first caprock is a playa type mudstone of the Weser and Arnstadt formations directly overlying the Stuttgart formation. Laboratory tests revealed permeabilities in a µDarcy-range. The second main caprock is a tertiary clay, the so-called Rupelton. To determine the maximum injection pressure modified leak-off tests (without fracturing the caprock) were performed resulting in values around 120 bar. Due to safety standards the pressure threshold is set to 82 bar until more experience on the reservoir behaviour is available. The sealing property of the secondary cap rock is well known from decades of natural gas storage operations at the testing site and was the basis for the permission to operate the CO2 storage by the mining authority. Undisturbed, initial reservoir conditions are 35 °C and 62 bar. The initial reservoir fluid is highly saline with about 235 g/l total dissolved solids primarily composed of sodium chloride with notable amounts of calcium chloride. The initial pH value is 6.6. Hydraulic tests as well as laboratory tests revealed a permeability between 50 and 100 mDarcy for the sand channels of the storage formation. Within twenty months of storage operation, about 30,000 t of CO2 have been injected. Spreading of the CO2 plume is monitored by a broad range of geophysical techniques. The injection well and the two

  4. Regulating the geological sequestration of CO2.

    PubMed

    Wilson, Elizabeth J; Morgan, M Granger; Apt, Jay; Bonner, Mark; Bunting, Christopher; Gode, Jenny; Haszeldine, R Stuart; Jaeger, Carlo C; Keith, David W; Mccoy, Sean T; Pollak, Melisa F; Reiner, David M; Rubin, Edward S; Torvanger, Asbjørn; Ulardic, Christina; Vajjhala, Shalini P; Victor, David G; Wright, Iain W

    2008-04-15

    Governments worldwide should provide incentives for initial large-scale GS projects to help build the knowledge base for a mature, internationally harmonized GS regulatory framework. Health, safety, and environmental risks of these early projects can be managed through modifications of existing regulations in the EU, Australia, Canada, and the U.S. An institutional mechanism, such as the proposed Federal Carbon Sequestration Commission in the U.S., should gather data from these early projects and combine them with factors such as GS industrial organization and climate regime requirements to create an efficient and adaptive regulatory framework suited to large-scale deployment. Mechanisms to structure long-term liability and fund long-term postclosure care must be developed, most likely at the national level, to equitably balance the risks and benefits of this important climate change mitigation technology. We need to do this right. During the initial field experiences, a single major accident, resulting from inadequate regulatory oversight, anywhere in the world, could seriously endanger the future viability of GS. That, in turn, could make it next to impossible to achieve the needed dramatic global reductions in CO2 emissions over the next several decades. We also need to do it quickly. Emissions are going up, the climate is changing, and impacts are growing. The need for safe and effective CO2 capture with deep GS is urgent.

  5. Public Acceptance for Geological CO2-Storage

    NASA Astrophysics Data System (ADS)

    Schilling, F.; Ossing, F.; Würdemann, H.; Co2SINK Team

    2009-04-01

    Public acceptance is one of the fundamental prerequisites for geological CO2 storage. In highly populated areas like central Europe, especially in the vicinity of metropolitan areas like Berlin, underground operations are in the focus of the people living next to the site, the media, and politics. To gain acceptance, all these groups - the people in the neighbourhood, journalists, and authorities - need to be confident of the security of the planned storage operation as well as the long term security of storage. A very important point is to show that the technical risks of CO2 storage can be managed with the help of a proper short and long term monitoring concept, as well as appropriate mitigation technologies e.g adequate abandonment procedures for leaking wells. To better explain the possible risks examples for leakage scenarios help the public to assess and to accept the technical risks of CO2 storage. At Ketzin we tried the following approach that can be summed up on the basis: Always tell the truth! This might be self-evident but it has to be stressed that credibility is of vital importance. Suspiciousness and distrust are best friends of fear. Undefined fear seems to be the major risk in public acceptance of geological CO2-storage. Misinformation and missing communication further enhance the denial of geological CO2 storage. When we started to plan and establish the Ketzin storage site, we ensured a forward directed communication. Offensive information activities, an information centre on site, active media politics and open information about the activities taking place are basics. Some of the measures were: - information of the competent authorities through meetings (mayor, governmental authorities) - information of the local public, e.g. hearings (while also inviting local, regional and nation wide media) - we always treated the local people and press first! - organizing of bigger events to inform the public on site, e.g. start of drilling activities (open

  6. Translating crustacean biological responses from CO2 ...

    EPA Pesticide Factsheets

    Many studies of animal responses to ocean acidification focus on uniformly conditioned age cohorts that lack complexities typically found in wild populations. These studies have become the primary data source for predicting higher level ecological effects, but the roles of intraspecific interactions in re-shaping biological, demographic and evolutionary responses are not commonly considered. To explore this problem, I assessed responses in the mysid Americamysis bahia to bubbling of CO2-enriched and un-enriched air into the seawater supply in flow-through aquariums. I conducted one experiment using isolated age cohorts and a separate experiment using intact populations. The seawater supply was continuously input from Narragansett Bay (Rhode Island, USA). The 28-day cohort study was maintained without resource or spatial limitations, whereas the 5-month population study consisted of stage-structured populations that were allowed to self-regulate. These differences are common features of experiments and were intentionally retained to demonstrate the effect of methodological approaches on perceptions of effect mechanisms. The CO2 treatment reduced neonate abundance in the cohort experiment (24% reduction due to a mean pH difference of −0.27) but not in the population experiment, where effects were small and were strongest for adult and stage 1 survival (3% change due to a mean pH difference of −0.25). I also found evidence of competition in the population exper

  7. Uncertainty in gridded CO2 emissions estimates

    NASA Astrophysics Data System (ADS)

    Hogue, Susannah; Marland, Eric; Andres, Robert J.; Marland, Gregg; Woodard, Dawn

    2016-05-01

    We are interested in the spatial distribution of fossil-fuel-related emissions of CO2 for both geochemical and geo