Deployment of Low-Cost, Carbon Dioxide Sensors throughout the Washington Metropolitan Area - The Capital Climate Initiative

NASA Astrophysics Data System (ADS)

Caine, Kristen M.; Bailey, D. Michelle; Houston Miller, J.

2016-04-01

According to the IPCC from 1995 to 2005, atmospheric carbon dioxide (CO2) concentrations increased by 19 ppm, the highest average growth rate recorded for any decade since measurements began in the 1950s. Due to its ability to influence global climate change, it is imperative to continually monitor carbon dioxide emission levels, particularly in urban areas where some estimate in excess of 75% of total greenhouse gas emissions occur. Although high-precision sensors are commercially available, these are not cost effective for mapping a large spatial area. A goal of this research is to build out a network of sensors that are accurate and precise enough to provide a valuable data tool for accessing carbon emissions from a large, urban area. This publically available greenhouse gas dataset can be used in numerous environmental assessments and as validation for remote sensing products. It will also be a valuable teaching tool for classes at our university and will promote further engagement of K-12 students and their teachers through education and outreach activities. Each of our sensors (referred to as "PiOxides") utilizes a non-dispersive infrared (NDIR) sensor for the detection of carbon dioxide along with a combination pressure/temperature/humidity sensor. The collection of pressure and temperature increases the accuracy and precision of the CO2 measurement. The sensors communicate using a serial interfaces with a Raspberry Pi microcontroller. Each PiOxide is connected to a website that leverages recent developments in open source GIS tools. In this way, data from individual sensors can be followed individually or aggregated to provide real-time, spatially-resolved data of CO2 trends across a broad area. Our goal for the network is to expand across the entire DC/Maryland/Virginia Region through partnerships with private and public schools. We are also designing GHG Bluetooth beacons that may be accessed by mobile phone users in their vicinity. In two additional applications, PiOxides are being deployed as a part of an innovative open networking platform being installed on LED street lights in Washington, DC and in a black spruce forest near Fairbanks, Alaska for the detection of carbon dioxide above thawing permafrost.

Comparison of buried soil sensors, surface chambers and above ground measurements of carbon dioxide fluxes

USDA-ARS?s Scientific Manuscript database

Soil carbon dioxide (CO2) flux is an important component of the terrestrial carbon cycle. Accurate measurements of soil CO2 flux aids determinations of carbon budgets. In this study, we investigated soil CO2 fluxes with time and depth and above ground CO2 fluxes in a bare field. CO2 concentrations w...

Crewmember repairing the Regenerative Carbon Dioxide Removal System wiring.

NASA Technical Reports Server (NTRS)

1992-01-01

Mission Pilot Ken Bowersox, busy at work on the wiring harness for the Regenerative Carbon Dioxide Removal System located under the mid deck floor. Photo shows Bowersox splicing wires together to 'fool' a faulty sensor that caused the 'air conditioner' to shut down.

Vanadium doped tin dioxide as a novel sulfur dioxide sensor.

PubMed

Das, S; Chakraborty, S; Parkash, O; Kumar, D; Bandyopadhyay, S; Samudrala, S K; Sen, A; Maiti, H S

2008-04-15

Considering the short-term exposure limit of SO2 to be 5 ppm, we first time report that semiconductor sensors based on vanadium doped SnO2 can be used for SO2 leak detection because of their good sensitivity towards SO2 at concentrations down to 5 ppm. Such sensors are quite selective in presence of other gases like carbon monoxide, methane and butane. The high sensitivity of vanadium doped tin dioxide towards SO2 may be understood by considering the oxidation of sulfur dioxide to sulfur trioxide on SnO2 surface through redox cycles of vanadium-sulfur-oxygen adsorbed species.

Non-Intrusive, Distributed Gas Sensing Technology for Advanced Spacesuits

NASA Technical Reports Server (NTRS)

Delgado, Jesus; Phillips, Straun; Rubtsov, Vladimir; Chullen, Cinda

2015-01-01

Chemical sensors for monitoring gas composition, including oxygen, humidity, carbon dioxide, and trace contaminants are needed to characterize and validate spacesuit design and operating parameters. This paper reports on the first prototypes of a non-intrusive gas sensing technology based on flexible sensitive patches positioned inside spacesuit prototypes and interrogated by optical fibers routed outside the suit, taking advantage of the transparent materials of the suit prototypes. The sensitive patches are based on luminescent materials whose emission parameters vary with the partial pressure of a specific gas. Patches sensitive to carbon dioxide, humidity, oxygen, and ammonia have been developed, and their preliminary characterization in the laboratory using Mark III-like helmet parts is described. The first prototype system consists of a four-channel fiber optic luminescent detector that can be used to monitor any of the selected target gases at four locations. To switch from one gas to another we replace the (disposable) sensor patches and adjust the system settings. Repeatability among sensitive patches and of sensor performance from location to location has been confirmed, assuring that suit engineers will have flexibility in selecting multiple sensing points, fitting the sensor elements into the spacesuit, and easily repositioning the sensor elements as desired. The evaluation of the first prototype for monitoring carbon dioxide during washout studies in a space suit prototype is presented.

Non-Intrusive, Distributed Gas Sensing Technology for Advanced Spacesuits

NASA Technical Reports Server (NTRS)

Delgado, Jesus; Phillips, Straun; Rubtsov, Vladimir; Chullen, Cinda

2015-01-01

Chemical sensors for monitoring gas composition, including oxygen, humidity, carbon dioxide, and trace contaminants, are needed to characterize and validate spacesuit design and operating parameters. This paper reports on the first prototypes of a non-intrusive gas sensing technology based on flexible sensitive patches positioned inside spacesuit prototypes and interrogated via optical fibers routed outside the suit, taking advantage of the transparent materials of the suit prototypes. The sensitive patches are based on luminescent materials whose emission parameters vary with the partial pressure of a specific gas. Patches sensitive to carbon dioxide, humidity, and temperature have been developed, and their preliminary laboratory characterization in Mark III-like helmet parts is described. The first prototype system consists of a four-channel fiber optic luminescent detector that can be used to monitor any of the selected target gases at four locations. To switch from one gas to another we replace the (disposable) sensor patches and adjust the system settings. Repeatability among sensitive patches and of sensor performance from location to location has been confirmed, assuring that suit engineers will have flexibility in selecting multiple sensing points, fitting the sensor elements into the spacesuit, and easily repositioning the sensor elements as desired. The evaluation of the first prototype for monitoring carbon dioxide during washout studies in a spacesuit prototype is presented.

Community Air Sensor Network (CAIRSENSE) project ...

EPA Pesticide Factsheets

Advances in air pollution sensor technology have enabled the development of small and low cost systems to measure outdoor air pollution. The deployment of a large number of sensors across a small geographic area would have potential benefits to supplement traditional monitoring networks with additional geographic and temporal measurement resolution, if the data quality were sufficient. To understand the capability of emerging air sensor technology, the Community Air Sensor Network (CAIRSENSE) project deployed low cost, continuous and commercially-available air pollution sensors at a regulatory air monitoring site and as a local sensor network over a surrounding ~2 km area in Southeastern U.S. Co-location of sensors measuring oxides of nitrogen, ozone, carbon monoxide, sulfur dioxide, and particles revealed highly variable performance, both in terms of comparison to a reference monitor as well as whether multiple identical sensors reproduced the same signal. Multiple ozone, nitrogen dioxide, and carbon monoxide sensors revealed low to very high correlation with a reference monitor, with Pearson sample correlation coefficient (r) ranging from 0.39 to 0.97, -0.25 to 0.76, -0.40 to 0.82, respectively. The only sulfur dioxide sensor tested revealed no correlation (r 0.5), step-wise multiple linear regression was performed to determine if ambient temperature, relative humidity (RH), or age of the sensor in sampling days could be used in a correction algorihm to im

Measurement of Near-Surface Carbon Dioxide Concentrations with an Open-Path Tunable Diode Laser Sensor and a Non-Dispersive Infrared Sensor at the Bonanza Creek Long Term Ecological Research Site near Fairbanks, Alaska

NASA Astrophysics Data System (ADS)

Bailey, D. M.; Caine, K. M.; Miller, J. H. H.

2016-12-01

Continuous collection of carbon dioxide (CO2) concentrations is imperative in understanding seasonal and inter-annual variability of carbon feedbacks above thawing permafrost. Permafrost makes up one-quarter of the Earth's terrestrial surface and has the potential to release twice the amount of carbon than is currently in the atmosphere if global temperatures continue to increase. A collaborative effort with the University of Alaska - Fairbanks, NASA Goddard Space Flight Center, and our group at George Washington University is underway to monitor these feedbacks near Fairbanks, Alaska. In June 2016, we deployed an open-path tunable diode laser sensor along with a non-dispersive infrared (NDIR) sensor at the Bonanza Creek Long Term Ecological Research Site as an exploratory study for their use in collecting near-surface CO2 concentrations above thawing permafrost. The open-path instrument (OPI) collected spatially-integrated measurements approximately 1.5 meters above the surface of a young thermokarst bog over a 15-day period whereas the NDIR sensor collected localized measurements 1 meter above the surface for 16 days. Near-continuous measurements were achieved with the NDIR sensor which was limited only by the availability of solar-produced power. The OPI measurements were further limited by maintaining laser alignment under changing environmental conditions. However, the campaign achieved a nearly 80% duty cycle for the entire test period. Here we compare both the localized and spatially-integrated carbon dioxide measurements and their observed diurnal concentration cycles, whose magnitude showed a strong dependence on daily weather at the test site.

A Novel Real-time Carbon Dioxide Analyzer for Health and Environmental Applications

PubMed Central

Zhao, Di; Miller, Dylan; Xian, Xiaojun; Tsow, Francis

2014-01-01

To be able to detect carbon dioxide (CO2) with high accuracy and fast response time is critical for many health and environmental applications. We report on a pocket-sized CO2 sensor for real-time analysis of end-tidal CO2, and environmental CO2. The sensor shows fast and reversible response to CO2 over a wide concentration range, covering the needs of both environmental and health applications. It is also immune to the presence of various interfering gases in ambient or expired air. Furthermore, the sensor has been used for real-time breath analysis, and the results are in good agreement with those from a commercial CO2 detector. PMID:24659857

A Novel Real-time Carbon Dioxide Analyzer for Health and Environmental Applications.

PubMed

Zhao, Di; Miller, Dylan; Xian, Xiaojun; Tsow, Francis; Forzani, Erica S

2014-05-01

To be able to detect carbon dioxide (CO 2 ) with high accuracy and fast response time is critical for many health and environmental applications. We report on a pocket-sized CO 2 sensor for real-time analysis of end-tidal CO 2, and environmental CO 2 . The sensor shows fast and reversible response to CO 2 over a wide concentration range, covering the needs of both environmental and health applications. It is also immune to the presence of various interfering gases in ambient or expired air. Furthermore, the sensor has been used for real-time breath analysis, and the results are in good agreement with those from a commercial CO 2 detector.

A Portable Array-Type Optical Fiber Sensing Instrument for Real-Time Gas Detection

PubMed Central

Hung, San-Shan; Chang, Hsing-Cheng; Chang, I-Nan

2016-01-01

A novel optical fiber array-type of sensing instrument with temperature compensation for real-time detection was developed to measure oxygen, carbon dioxide, and ammonia simultaneously. The proposed instrument is multi-sensing array integrated with real-time measurement module for portable applications. The sensing optical fibers were etched and polished before coating to increase sensitivities. The ammonia and temperature sensors were each composed of a dye-coated single-mode fiber with constructing a fiber Bragg grating and a long-period filter grating for detecting light intensity. Both carbon dioxide and oxygen sensing structures use multimode fibers where 1-hydroxy-3,6,8-pyrene trisulfonic acid trisodium salt is coated for carbon dioxide sensing and Tris(2,2′-bipyridyl) dichlororuthenium(II) hexahydrate and Tris(bipyridine)ruthenium(II) chloride are coated for oxygen sensing. Gas-induced fluorescent light intensity variation was applied to detect gas concentration. The portable gas sensing array was set up by integrating with photo-electronic measurement modules and a human-machine interface to detect gases in real time. The measured data have been processed using piecewise-linear method. The sensitivity of the oxygen sensor were 1.54%/V and 9.62%/V for concentrations less than 1.5% and for concentrations between 1.5% and 6%, respectively. The sensitivity of the carbon dioxide sensor were 8.33%/V and 9.62%/V for concentrations less than 2% and for concentrations between 2% and 5%, respectively. For the ammonia sensor, the sensitivity was 27.78%/V, while ammonia concentration was less than 2%. PMID:27941636

A Portable Array-Type Optical Fiber Sensing Instrument for Real-Time Gas Detection.

PubMed

Hung, San-Shan; Chang, Hsing-Cheng; Chang, I-Nan

2016-12-08

A novel optical fiber array-type of sensing instrument with temperature compensation for real-time detection was developed to measure oxygen, carbon dioxide, and ammonia simultaneously. The proposed instrument is multi-sensing array integrated with real-time measurement module for portable applications. The sensing optical fibers were etched and polished before coating to increase sensitivities. The ammonia and temperature sensors were each composed of a dye-coated single-mode fiber with constructing a fiber Bragg grating and a long-period filter grating for detecting light intensity. Both carbon dioxide and oxygen sensing structures use multimode fibers where 1-hydroxy-3,6,8-pyrene trisulfonic acid trisodium salt is coated for carbon dioxide sensing and Tris(2,2'-bipyridyl) dichlororuthenium(II) hexahydrate and Tris(bipyridine)ruthenium(II) chloride are coated for oxygen sensing. Gas-induced fluorescent light intensity variation was applied to detect gas concentration. The portable gas sensing array was set up by integrating with photo-electronic measurement modules and a human-machine interface to detect gases in real time. The measured data have been processed using piecewise-linear method. The sensitivity of the oxygen sensor were 1.54%/V and 9.62%/V for concentrations less than 1.5% and for concentrations between 1.5% and 6%, respectively. The sensitivity of the carbon dioxide sensor were 8.33%/V and 9.62%/V for concentrations less than 2% and for concentrations between 2% and 5%, respectively. For the ammonia sensor, the sensitivity was 27.78%/V, while ammonia concentration was less than 2%.

Low-cost photonic sensors for carbon dioxide exchange rate measurement

NASA Astrophysics Data System (ADS)

Bieda, Marcin S.; Sobotka, Piotr; Lesiak, Piotr; Woliński, Tomasz R.

2017-10-01

Carbon dioxide (CO2) measurement has an important role in atmosphere monitoring. Usually, two types of measurements are carried out. The first one is based on gas concentration measurement while the second involves gas exchange rate measurement between earth surface and atmosphere [1]. There are several methods which allow gas concentration measurement. However, most of them require expensive instrumentation or large devices (i.e. gas chambers). In order to precisely measure either CO2 concentration or CO2 exchange rate, preferably a sensors network should be used. These sensors must have small dimensions, low power consumption, and they should be cost-effective. Therefore, this creates a great demand for a robust low-power and low-cost CO2 sensor [2,3]. As a solution, we propose a photonic sensor that can measure CO2 concentration and also can be used to measure gas exchange by using the Eddy covariance method [1].

Miniaturized Amperometric Solid Electrolyte Carbon Dioxide Sensors

NASA Technical Reports Server (NTRS)

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

2006-01-01

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

Carbon dioxide sensor. [partial pressure measurement using monochromators

NASA Technical Reports Server (NTRS)

1975-01-01

Analytical techniques for measuring CO2 were evaluated and rated for use with the advanced extravehicular mobility unit. An infrared absorption concept using a dual-wavelength monochromator was selected for investigation. A breadboard carbon dioxide sensor (CDS) was assembled and tested. The CDS performance showed the capability of measuring CO2 over the range of 0 to 4.0 kPa (0 to 30 mmHg) P sub (CO2). The volume and weight of a flight configured CDS should be acceptable. It is recommended that development continue to complete the design of a flight prototype.

Importance of network density of nanotube: Effect on nitrogen dioxide gas sensing by solid state resistive sensor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mishra, Prabhash; Grachyova, D. V.; Moskalenko, A. S.

2016-04-13

Dispersion of single-walled carbon nanotubes (SWCNTs) is an established fact, however, its effect on toxic gas sensing for the development of solid state resistive sensor was not well reported. In this report, the dispersion quality of SWCNTs has been investigated and improved, and this well-dispersed SWCNTs network was used for sensor fabrication to monitor nitrogen dioxide gas. Ultraviolet (UV)-visible spectroscopic studies shows the strength of SWNTs dispersion and scanning electron microscopy (SEM) imaging provides the morphological properties of the sensor device. In this gas sensor device, two sets of resistive type sensors were fabricated that consisting of a pair ofmore » interdigitated electrodes (IDEs) using dielectrophoresis technique with different SWCNTs network density. With low-density SWCNTs networks, this fabricated sensor exhibits a high response for nitrogen dioxide sensing. The sensing of nitrogen dioxide is mainly due to charge transfer from absorbed molecules to sidewalls of nanotube and tube-tube screening acting a major role for the transport properties of charge carriers.« less

Ionic Liquid-Based Optical and Electrochemical Carbon Dioxide Sensors.

PubMed

Behera, Kamalakanta; Pandey, Shubha; Kadyan, Anu; Pandey, Siddharth

2015-12-04

Due to their unusual physicochemical properties (e.g., high thermal stability, low volatility, high intrinsic conductivity, wide electrochemical windows and good solvating ability), ionic liquids have shown immense application potential in many research areas. Applications of ionic liquid in developing various sensors, especially for the sensing of biomolecules, such as nucleic acids, proteins and enzymes, gas sensing and sensing of various important ions, among other chemosensing platforms, are currently being explored by researchers worldwide. The use of ionic liquids for the detection of carbon dioxide (CO₂) gas is currently a major topic of research due to the associated importance of this gas with daily human life. This review focuses on the application of ionic liquids in optical and electrochemical CO₂ sensors. The design, mechanism, sensitivity and detection limit of each type of sensor are highlighted in this review.

Ionic Liquid-Based Optical and Electrochemical Carbon Dioxide Sensors

PubMed Central

Behera, Kamalakanta; Pandey, Shubha; Kadyan, Anu; Pandey, Siddharth

2015-01-01

Due to their unusual physicochemical properties (e.g., high thermal stability, low volatility, high intrinsic conductivity, wide electrochemical windows and good solvating ability), ionic liquids have shown immense application potential in many research areas. Applications of ionic liquid in developing various sensors, especially for the sensing of biomolecules, such as nucleic acids, proteins and enzymes, gas sensing and sensing of various important ions, among other chemosensing platforms, are currently being explored by researchers worldwide. The use of ionic liquids for the detection of carbon dioxide (CO2) gas is currently a major topic of research due to the associated importance of this gas with daily human life. This review focuses on the application of ionic liquids in optical and electrochemical CO2 sensors. The design, mechanism, sensitivity and detection limit of each type of sensor are highlighted in this review. PMID:26690155

Persistent regional carbon dioxide anomalies driven by land use

NASA Astrophysics Data System (ADS)

Schultz, Colin

2012-04-01

Researchers have traditionally used measurements from remote locations, such as Hawaii's Mauna Loa Observatory and other isolated stations, to determine atmospheric carbon dioxide (CO2) concentrations and estimate the strengths of various carbon sources and sinks. The prevailing wisdom was that attempts to measure regional differences in CO2 over land would end up with signals that were either so small that they were undetectable or that were dominated by high-frequency variability due to atmospheric turbulence or weather. Measurements drawn from a moderately dense network of atmospheric gas composition sensors distributed across the upper midwestern United States, however, showed that large regional variations in tropospheric CO2 are readily observable. Drawing on measurements made at nine sensors spread over 400,000 square kilometers between 2007 and 2009, Miles et al. found that seasonal variations in atmospheric CO2 depend strongly on the type of ecosystem lying at the foot of each sensor tower.

Optical sensors for application in intelligent food-packaging technology

NASA Astrophysics Data System (ADS)

McEvoy, Aisling K.; Von Bueltzingsloewen, Christoph; McDonagh, Colette M.; MacCraith, Brian D.; Klimant, Ingo; Wolfbeis, Otto S.

2003-03-01

Modified Atmosphere Packaged (MAP) food employs a protective gas mixture, which normally contains selected amounts of carbon dioxide (CO2) and oxygen (O2), in order to extend the shelf life of food. Conventional MAP analysis of package integrity involves destructive sampling of packages followed by carbon dioxide and oxygen detection. For quality control reasons, as well as to enhance food safety, the concept of optical on-pack sensors for monitoring the gas composition of the MAP package at different stages of the distribution process is very attractive. The objective of this work was to develop printable formulations of oxygen and carbon dioxide sensors for use in food packaging. Oxygen sensing is achieved by detecting the degree of quenching of a fluorescent ruthenium complex entrapped in a sol-gel matrix. In particular, a measurement technique based on the quenching of the fluorescence decay time, phase fluorometric detection, is employed. A scheme for detecting CO2 has been developed which is compatible with the oxygen detection scheme. It is fluorescence-based and uses the pH-sensitive 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) indicator dye encapsulated in an organically modified silica (ORMOSIL) glass matrix. Dual Luminophore Referencing (DLR) has been employed as an internal referencing scheme, which provides many of the advantages of lifetime-based fluorometric methods. Oxygen cross-sensitivity was minimised by encapsulating the reference luminophore in dense sol-gel microspheres. The sensor performance compared well with standard methods for both oxygen and carbon dioxide detection. The results of preliminary on-pack print trials are presented and a preliminary design of an integrated dual gas optical read-out device is discussed.

Application of Commercial Non-Dispersive Infrared Spectroscopy Sensors for Sub-Ambient Carbon Dioxide Detection

NASA Technical Reports Server (NTRS)

Swickrath, Michael J.; Anderson, Molly; McMillin, Summer; Broerman, Craig

2012-01-01

Monitoring carbon dioxide (CO2) concentration within a spacecraft or spacesuit is critically important to ensuring the safety of the crew. Carbon dioxide uniquely absorbs light at wavelengths of 3.95 micrometers and 4.26 micrometers. As a result, non-dispersive infrared (NDIR) spectroscopy can be employed as a reliable and inexpensive method for the quantification of CO2 within the atmosphere. A multitude of commercial off-the-shelf (COTS) NDIR sensors exist for CO2 quantification. The COTS sensors provide reasonable accuracy as long as the measurements are attained under conditions close to the calibration conditions of the sensor (typically 21.1 C (70.0 F) and 1 atmosphere). However, as pressure deviates from atmospheric to the pressures associated with a spacecraft (8.0{10.2 pounds per square inch absolute (psia)) or spacesuit (4.1{8.0 psia), the error in the measurement grows increasingly large. In addition to pressure and temperature dependencies, the infrared transmissivity through a volume of gas also depends on the composition of the gas. As the composition is not known a priori, accurate sub-ambient detection must rely on iterative sensor compensation techniques. This manuscript describes the development of recursive compensation algorithms for sub-ambient detection of CO2 with COTS NDIR sensors. In addition, the source of the exponential loss in accuracy is developed theoretically. The basis of the loss can be explained through thermal, Doppler, and Lorentz broadening effects that arise as a result of the temperature, pressure, and composition of the gas mixture under analysis. This manuscript provides an approach to employing COTS sensors at sub-ambient conditions and may also lend insight into designing future NDIR sensors for aerospace application.

Application of Commercial Non-Dispersive Infrared Spectroscopy Sensors for Sub-Ambient Carbon Dioxide Detection

NASA Technical Reports Server (NTRS)

Swickrath, Michael J.; Anderson, Molly; McMillin, Summer; Boerman, Craig

2011-01-01

Monitoring carbon dioxide (CO2) concentration within a spacecraft or spacesuit is critically important to ensuring the safety of the crew. Carbon dioxide uniquely absorbs light at wavelengths of 3.95 micrometers and 4.26 micrometers. As a result, non-dispersive infrared (NDIR) spectroscopy can be employed as a reliable and inexpensive method for the quantification of CO2 within the atmosphere. A multitude of commercial-off-the-shelf (COTS) NDIR sensors exist for CO2 quantification. The COTS sensors provide reasonable accuracy so long as the measurements are attained under conditions close to the calibration conditions of the sensor (typically 21.1 C and 1 atm). However, as pressure deviates from atmospheric to the pressures associated with a spacecraft (8.0-10.2 PSIA) or spacesuit (4.1-8.0 PSIA), the error in the measurement grows increasingly large. In addition to pressure and temperature dependencies, the infrared transmissivity through a volume of gas also depends on the composition of the gas. As the composition is not known a priori, accurate sub-ambient detection must rely on iterative sensor compensation techniques. This manuscript describes the development of recursive compensation algorithms for sub-ambient detection of CO2 with COTS NDIR sensors. In addition, the basis of the exponential loss in accuracy is developed theoretically considering thermal, Doppler, and Lorentz broadening effects which arise as a result of the temperature, pressure, and composition of the gas mixture under analysis. As a result, this manuscript provides an approach to employing COTS sensors at sub-ambient conditions and may also lend insight into designing future NDIR sensors for aerospace application.

Oxygen and carbon dioxide sensing

NASA Technical Reports Server (NTRS)

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

2012-01-01

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

Development of an integrated sensor module for a non-invasive respiratory monitoring system

NASA Astrophysics Data System (ADS)

Kang, Seok-Won; Chang, Keun-Shik

2013-09-01

A respiratory monitoring system has been developed for analyzing the carbon dioxide (CO2) and oxygen (O2) concentrations in the expired air using gas sensors. The data can be used to estimate some medical conditions, including diffusion capability of the lung membrane, oxygen uptake, and carbon dioxide output. For this purpose, a 3-way valve derived from a servomotor was developed, which operates synchronously with human respiratory signals. In particular, the breath analysis system includes an integrated sensor module for valve control, data acquisition through the O2 and CO2 sensors, and respiratory rate monitoring, as well as software dedicated to analysis of respiratory gasses. In addition, an approximation technique for experimental data based on Haar-wavelet-based decomposition is explored to remove noise as well as to reduce the file size of data for long-term monitoring.

Fluorescent Dye-doped Sol-gel Sensor for Highly Sensitive Carbon Dioxide Gas Detection below Atmospheric Concentrations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dansby-Sparks, Royce N.; Jin, Jun; Mechery, Shelly J

2009-01-01

Optical fluorescence sol-gel sensors have been developed for the detection of carbon dioxide gas in the 0.03?30% range with a detection limit of 0.008% (or 80 ppm) and a quantitation limit of 0.02% (or 200 ppm) CO{sub 2}. Sol?gels were spin-coated on glass slides to create an organically modified silica-doped matrix with the 1-hydroxypyrene-3,6,8-trisulfonate (HPTS) fluorescent indicator. The luminescence intensity of the HPTS indicator (513 nm) is quenched by CO{sub 2}, which protonates the anionic form of HPTS. An ion pair technique was used to incorporate the lipophilic dye into the hydrophilic sol?gel matrix. TiO{sub 2} particles (<5 {mu}m diameter)more » were added to induce Mie scattering and increase the incident light interaction with the sensing film, thus increasing the signal-to-noise ratio. Moisture-proof overcoatings have been used to maintain a constant level of water inside the sensor films. The optical sensors are inexpensive to prepare and can be easily coupled to fiber optics for remote sensing capabilities. A fiber-optic bundle was used for the gas detection and shown to work as part of a multianalyte platform for simultaneous detection of multiple analytes. The studies reported here resulted in the development of sol?gel optical fluorescent sensors for CO{sub 2} gas with sensitivity below that in the atmosphere (ca. 387 ppm). These sensors are a complementary approach to current FT-IR measurements for real-time carbon dioxide detection in environmental applications.« less

Recent developments of optical fiber chemical sensors at IROE

NASA Astrophysics Data System (ADS)

Baldini, Francesco

2002-02-01

An overview is given on the activity in progress at IROE, relative to the field of optical fibre sensors for chemical parameters. Optode-based sensors are under development for both biomedical and environmental applications. As for the biomedical field, particular attention will be devoted to clinical applications of the developed sensor in gastroenterology. The first clinical applications of an absorption-based sensor for the detection of gastric carbon dioxide will be described. Clinical results have shown the superiority of the developed sensor over the sensor currently available on the market and based on air tonometry. New clinical findings involving a sensor for the detection of bile will be also discussed. As far as environmental applications are concerned, an optode for the detection of nitrogen dioxide will be described.

Microfabricated Chemical Sensors for Safety and Emission Control Applications

NASA Technical Reports Server (NTRS)

Hunter, G. W.; Neudeck, P. G.; Chen, L.-Y.; Knight, D.; Liu, C. C.; Wu, Q. H.

1998-01-01

Chemical sensor technology is being developed for leak detection, emission monitoring, and fire safety applications. The development of these sensors is based on progress in two types of technology: 1) Micromachining and microfabrication (MicroElectroMechanical Systems (MEMS)-based) technology to fabricate miniaturized sensors. 2) The development of high temperature semiconductors, especially silicon carbide. Using these technologies, sensors to measure hydrogen, hydrocarbons, nitrogen oxides, carbon monoxide, oxygen, and carbon dioxide are being developed. A description is given of each sensor type and its present stage of development. It is concluded that microfabricated sensor technology has significant potential for use in a range of aerospace applications.

Oxidation of Hydrocarbons on the Surface of Tin Dioxide Chemical Sensors

PubMed Central

Teterycz, Helena; Halek, Patryk; Wiśniewski, Kamil; Halek, Grzegorz; Koźlecki, Tomasz; Polowczyk, Izabela

2011-01-01

The paper presents the results of our investigation on the effect of the molecular structure of organic vapors on the characteristics of resistive chemical gas sensors. The sensors were based on tin dioxide and prepared by means of thick film technology. The electrical and catalytic examinations showed that the abstraction of two hydrogen atoms from the organic molecule and formation of a water in result of reaction with a chemisorbed oxygen ion, determine the rate of oxidation reactions, and thus the sensor performance. The rate of the process depends on the order of carbon atoms and Lewis acidity of the molecule. Therefore, any modification of the surface centers of a sensor material, modifies not only the sensor sensitivity, but also its selectivity. PMID:22163855

Novel diode laser-based sensors for gas sensing applications

NASA Technical Reports Server (NTRS)

Tittel, F. K.; Lancaster, D. G.; Richter, D.

2000-01-01

The development of compact spectroscopic gas sensors and their applications to environmental sensing will be described. These sensors employ mid-infrared difference-frequency generation (DFG) in periodically poled lithium niobate (PPLN) crystals pumped by two single-frequency solid state lasers such as diode lasers, diode-pumped solid state, and fiber lasers. Ultrasensitive, highly selective, and real-time measurements of several important atmospheric trace gases, including carbon monoxide, nitrous oxide, carbon dioxide, formaldehyde [correction of formaldehye], and methane, have been demonstrated.

Theoretical investigation on multilayer nanocomposite-based fiber optic SPR sensor

NASA Astrophysics Data System (ADS)

Shojaie, Ehsan; Madanipour, Khosro; Gharibzadeh, Azadeh; Abbasi, Shabnam

2017-06-01

In this work, a multilayer nanocomposite based fiber optic SPR sensor is considered and especially designed for CO2 gas detection. This proposed fiber sensor consists of fiber core, gold-silver alloy and the absorber layers. The investigation is based on the evaluation of the transmitted-power derived under the transfer matrix method and the multiple-reflection in the sensing area. In terms of sensitivity, the sensor performance is studied theoretically under various conditions related to the metal layer and its gold and silver nanoparticles to form a single alloy film. Effect of additional parameters such as the ratio of the alloy composition and the thickness of the alloy film on the performance of the SPR sensor is studied, as well. Finally, a four-layer structure is introduced to detect carbon dioxide gas. It contains core fiber, gold-silver alloy layer, an absorbent layer of carbon dioxide gas (KOH) and measurement environment. Lower price and size are the main advantages of using such a sensor in compare with commercial (NDIR) gas sensor. Theoretical results show by increasing the metal layer thickness the sensitivity of sensor is increased, and by increasing the ratio of the gold in alloy the sensitivity is decreased.

Public webinar: Wildland Fire Sensors Challenge

EPA Science Inventory

This multi-agency challenge seeks a field-ready prototype system capable of measuring constituents of smoke, including particulates, carbon monoxide, ozone, and carbon dioxide, over the wide range of levels expected during wildland fires. The prototype system should be accurate, ...

Development and evaluation of optical fiber NH3 sensors for application in air quality monitoring

NASA Astrophysics Data System (ADS)

Huang, Yu; Wieck, Lucas; Tao, Shiquan

2013-02-01

Ammonia is a major air pollutant emitted from agricultural practices. Sources of ammonia include manure from animal feeding operations and fertilizer from cropping systems. Sensor technologies with capability of continuous real time monitoring of ammonia concentration in air are needed to qualify ammonia emissions from agricultural activities and further evaluate human and animal health effects, study ammonia environmental chemistry, and provide baseline data for air quality standard. We have developed fiber optic ammonia sensors using different sensing reagents and different polymers for immobilizing sensing reagents. The reversible fiber optic sensors have detection limits down to low ppbv levels. The response time of these sensors ranges from seconds to tens minutes depending on transducer design. In this paper, we report our results in the development and evaluation of fiber optic sensor technologies for air quality monitoring. The effect of change of temperature, humidity and carbon dioxide concentration on fiber optic ammonia sensors has been investigated. Carbon dioxide in air was found not interfere the fiber optic sensors for monitoring NH3. However, the change of humidity can cause interferences to some fiber optic NH3 sensors depending on the sensor's transducer design. The sensitivity of fiber optic NH3 sensors was found depends on temperature. Methods and techniques for eliminating these interferences have been proposed.

A light-emitting diode- (LED-) based absorption sensor for simultaneous detection of carbon monoxide and carbon dioxide

DOE PAGES

Thurmond, Kyle; Loparo, Zachary; Partridge, Jr., William P.; ...

2016-04-18

Here, a sensor was developed for simultaneous measurements of carbon monoxide (CO) and carbon dioxide (CO 2) fluctuations in internal combustion engine exhaust gases. This sensor utilizes low-cost and compact light-emitting diodes (LEDs) that emit in the 3–5 µm wavelength range. An affordable, fast response sensor that can measure these gases has a broad application that can lead to more efficient, fuel-flexible engines and regulation of harmful emissions. Light emission from LEDs is spectrally broader and more spatially divergent when compared to that of lasers, which presented many design challenges. Optical design studies addressed some of the non-ideal characteristics ofmore » the LED emissions. Measurements of CO and CO 2 were conducted using their fundamental absorption bands centered at 4.7 µm and 4.3 µm, respectively, while a 3.6 µm reference LED was used to account for scattering losses (due to soot, window deposits, etc.) common to the three measurement LEDs. Instrument validation and calibration was performed using a laboratory flow cell and bottled-gas mixtures. The sensor was able to detect CO 2 and CO concentration changes as small as 30 ppm and 400 ppm, respectively. Because of the many control and monitor species with infra-red absorption features, which can be measured using the strategy described, this work demonstrates proof of concept for a wider range of fast (250 Hz) and low-cost sensors for gas measurement and process monitoring.« less

Operations and Maintenance Manual, Atmospheric Contaminant Sensor, Revision B.

ERIC Educational Resources Information Center

National Aeronautics and Space Administration, Washington, DC.

The sensor is a mass spectrometer system which continuously monitors the atmospheric constituents of hydrogen, water vapor, nitrogen, oxygen, and carbon dioxide, and monitors the Freons on a demand sampling basis. The manual provides a system description, operational procedures, and maintenance and troubleshooting instructions. Circuit diagrams…

Operations and maintenance manual, atmospheric contaminant sensor, revision B

NASA Technical Reports Server (NTRS)

1972-01-01

The sensor is a mass spectrometer system which continuously monitors the atmospheric constituents of hydrogen, water vapor, nitrogen, oxygen, and carbon dioxide, and monitors the Freons on a demand sampling basis. The manual provides a system description, operational procedures, and maintenance and troubleshooting instructions. Circuit diagrams are included.

COCAP: a carbon dioxide analyser for small unmanned aircraft systems

NASA Astrophysics Data System (ADS)

Kunz, Martin; Lavric, Jost V.; Gerbig, Christoph; Tans, Pieter; Neff, Don; Hummelgård, Christine; Martin, Hans; Rödjegård, Henrik; Wrenger, Burkhard; Heimann, Martin

2018-03-01

Unmanned aircraft systems (UASs) could provide a cost-effective way to close gaps in the observation of the carbon cycle, provided that small yet accurate analysers are available. We have developed a COmpact Carbon dioxide analyser for Airborne Platforms (COCAP). The accuracy of COCAP's carbon dioxide (CO2) measurements is ensured by calibration in an environmental chamber, regular calibration in the field and by chemical drying of sampled air. In addition, the package contains a lightweight thermal stabilisation system that reduces the influence of ambient temperature changes on the CO2 sensor by 2 orders of magnitude. During validation of COCAP's CO2 measurements in simulated and real flights we found a measurement error of 1.2 µmol mol-1 or better with no indication of bias. COCAP is a self-contained package that has proven well suited for the operation on board small UASs. Besides carbon dioxide dry air mole fraction it also measures air temperature, humidity and pressure. We describe the measurement system and our calibration strategy in detail to support others in tapping the potential of UASs for atmospheric trace gas measurements.

Commercial Non-Dispersive Infrared Spectroscopy Sensors for Sub-Ambient Carbon Dioxide Detection

NASA Technical Reports Server (NTRS)

Swickrath, Michael J.; Anderson, Molly S.; McMillin, Summer; Broerman, Craig

2013-01-01

Carbon dioxide produced through respiration can accumulate rapidly within closed spaces. If not managed, a crew's respiratory rate increases, headaches and hyperventilation occur, vision and hearing are affected, and cognitive abilities decrease. Consequently, development continues on a number of CO2 removal technologies for human spacecraft and spacesuits. Terrestrially, technology development requires precise performance characterization to qualify promising air revitalization equipment. On-orbit, instrumentation is required to identify and eliminate unsafe conditions. This necessitates accurate in situ CO2 detection. Recursive compensation algorithms were developed for sub-ambient detection of CO2 with commercial off-the-shelf (COTS) non-dispersive infrared (NDIR) sensors. In addition, the source of the exponential loss in accuracy is developed theoretically. The basis of the loss can be explained through thermal, Doppler, and Lorentz broadening effects that arise as a result of the temperature, pressure, and composition of the gas mixture under analysis. The objective was to develop a mathematical routine to compensate COTS CO2 sensors relying on NDIR over pressures, temperatures, and compositions far from calibration conditions. The routine relies on a power-law relationship for the pressure dependency of the sensors along with an equivalent pressure to account for the composition dependency. A Newton-Raphson iterative technique solves for actual carbon dioxide concentration based on the reported concentration. Moreover, first principles routines were established to predict mixed-gas spectra based on sensor specifications (e.g., optical path length). The first principles model can be used to parametrically optimize sensors or sensor arrays across a wide variety of pressures/temperatures/ compositions. In this work, heuristic scaling arguments were utilized to develop reasonable compensation techniques. Experimental results confirmed this approach and provided evidence that composition broadening significantly alters spectra when pressure is reduced. Consequently, a recursive compensation technique was developed with the Newton-Raphson method, which was subsequently verified through experimentation.

Method and apparatus for real-time measurement of fuel gas compositions and heating values

DOEpatents

Zelepouga, Serguei; Pratapas, John M.; Saveliev, Alexei V.; Jangale, Vilas V.

2016-03-22

An exemplary embodiment can be an apparatus for real-time, in situ measurement of gas compositions and heating values. The apparatus includes a near infrared sensor for measuring concentrations of hydrocarbons and carbon dioxide, a mid infrared sensor for measuring concentrations of carbon monoxide and a semiconductor based sensor for measuring concentrations of hydrogen gas. A data processor having a computer program for reducing the effects of cross-sensitivities of the sensors to components other than target components of the sensors is also included. Also provided are corresponding or associated methods for real-time, in situ determination of a composition and heating value of a fuel gas.

A Light-Emitting Diode- (LED-) Based Absorption Sensor for Simultaneous Detection of Carbon Monoxide and Carbon Dioxide.

PubMed

Thurmond, Kyle; Loparo, Zachary; Partridge, William; Vasu, Subith S

2016-06-01

A sensor was developed for simultaneous measurements of carbon monoxide (CO) and carbon dioxide (CO2) fluctuations in internal combustion engine exhaust gases. This sensor utilizes low-cost and compact light-emitting diodes (LEDs) that emit in the 3-5 µm wavelength range. An affordable, fast response sensor that can measure these gases has a broad application that can lead to more efficient, fuel-flexible engines and regulation of harmful emissions. Light emission from LEDs is spectrally broader and more spatially divergent when compared to that of lasers, which presented many design challenges. Optical design studies addressed some of the non-ideal characteristics of the LED emissions. Measurements of CO and CO2 were conducted using their fundamental absorption bands centered at 4.7 µm and 4.3 µm, respectively, while a 3.6 µm reference LED was used to account for scattering losses (due to soot, window deposits, etc.) common to the three measurement LEDs. Instrument validation and calibration was performed using a laboratory flow cell and bottled-gas mixtures. The sensor was able to detect CO2 and CO concentration changes as small as 30 ppm and 400 ppm, respectively. Because of the many control and monitor species with infra-red absorption features, which can be measured using the strategy described, this work demonstrates proof of concept for a wider range of fast (250 Hz) and low-cost sensors for gas measurement and process monitoring. © The Author(s) 2016.

Characterization of amine-functionalized electrode for aqueous carbon dioxide (CO2) direct detection

NASA Astrophysics Data System (ADS)

Sato, Hiroshi

2017-03-01

In this study, fabrication of amino groups and ferrocenes co-modified sensor electrode and electrochemical detection of carbon dioxide (CO2) in the saline solution is reported. Electrochemical detection of CO2 was carried out using cyclic voltammetry in saline solution containing sodium bicarbonate as CO2 source. Oxidation and reduction peak current intensities computed from cyclic voltammograms varied as a function of concentration of CO2 molecules. The calibration curve was obtained by plotting oxidation peak current intensities as a function of CO2 concentration. The sensor electrode prepared in this study can estimate the differences between concentrations of CO2 in normal seawater up to 10 times higher. Furthermore, the surface analysis was performed to clarify the CO2 detection mechanism.

Cu-modified carbon spheres/reduced graphene oxide as a high sensitivity of gas sensor for NO2 detection at room temperature

NASA Astrophysics Data System (ADS)

Su, Zhibin; Tan, Li; Yang, Ruiqiang; Zhang, Yu; Tao, Jin; Zhang, Nan; Wen, Fusheng

2018-03-01

Nitrogen dioxide (NO2) as one of the most serious air pollution is harmful to people's health, therefore high-performance gas sensors is critically needed. Here, Cu-modified carbon spheres/reduced graphene oxide (Cu@CS/RGO) composite have been prepared as NO2 gas sensor material. Carbon sphere in the interlayer of RGO can increase the specific surface area of RGO. Copper nanoparticles decorated on the surface of CS can effectively enhance the adsorption activity of RGO as supplier of free electrons. The experimental results showed that its particular structure improved the gas sensitivity of RGO at different NO2 concentrations at room temperature.

Integration and application of optical chemical sensors in microbioreactors.

PubMed

Gruber, Pia; Marques, Marco P C; Szita, Nicolas; Mayr, Torsten

2017-08-08

The quantification of key variables such as oxygen, pH, carbon dioxide, glucose, and temperature provides essential information for biological and biotechnological applications and their development. Microfluidic devices offer an opportunity to accelerate research and development in these areas due to their small scale, and the fine control over the microenvironment, provided that these key variables can be measured. Optical sensors are well-suited for this task. They offer non-invasive and non-destructive monitoring of the mentioned variables, and the establishment of time-course profiles without the need for sampling from the microfluidic devices. They can also be implemented in larger systems, facilitating cross-scale comparison of analytical data. This tutorial review presents an overview of the optical sensors and their technology, with a view to support current and potential new users in microfluidics and biotechnology in the implementation of such sensors. It introduces the benefits and challenges of sensor integration, including, their application for microbioreactors. Sensor formats, integration methods, device bonding options, and monitoring options are explained. Luminescent sensors for oxygen, pH, carbon dioxide, glucose and temperature are showcased. Areas where further development is needed are highlighted with the intent to guide future development efforts towards analytes for which reliable, stable, or easily integrated detection methods are not yet available.

Process-Hardened, Multi-Analyte Sensor for Characterizing Rocket Plume Constituents

NASA Technical Reports Server (NTRS)

Goswami, Kisholoy

2011-01-01

A multi-analyte sensor was developed that enables simultaneous detection of rocket engine combustion-product molecules in a launch-vehicle ground test stand. The sensor was developed using a pin-printing method by incorporating multiple sensor elements on a single chip. It demonstrated accurate and sensitive detection of analytes such as carbon dioxide, carbon monoxide, kerosene, isopropanol, and ethylene from a single measurement. The use of pin-printing technology enables high-volume fabrication of the sensor chip, which will ultimately eliminate the need for individual sensor calibration since many identical sensors are made in one batch. Tests were performed using a single-sensor chip attached to a fiber-optic bundle. The use of a fiber bundle allows placement of the opto-electronic readout device at a place remote from the test stand. The sensors are rugged for operation in harsh environments.

Low-Power, Chip-Scale, Carbon Dioxide Gas Sensors for Spacesuit Monitoring

NASA Technical Reports Server (NTRS)

Rani, Asha; Shi, Chen; Thomson, Brian; Debnath, Ratan; Wen, Boamei; Motayed, Abhishek; Chullen, Cinda

2018-01-01

N5 Sensors, Inc. through a Small Business Technology Transfer (STTR) contract award has been developing ultra-small, low-power carbon dioxide (CO2) gas sensors, suited for monitoring CO2 levels inside NASA spacesuits. Due to the unique environmental conditions within the spacesuits, such as high humidity, large temperature swings, and operating pressure swings, measurement of key gases relevant to astronaut's safety and health such as(CO2), is quite challenging. Conventional non-dispersive infrared absorption based CO2 sensors present challenges inside the spacesuits due to size, weight, and power constraints, along with the ability to sense CO2 in a high humidity environment. Unique chip-scale, nanoengineered chemiresistive gas-sensing architecture has been developed for this application, which can be operated in a typical space-suite environmental conditions. Unique design combining the selective adsorption properties of the nanophotocatalytic clusters of metal-oxides and metals, provides selective detection of CO2 in high relative humidity conditions. All electronic design provides a compact and low-power solution, which can be implemented for multipoint detection of CO2 inside the spacesuits. This paper will describe the sensor architecture, development of new photocatalytic material for better sensor response, and advanced structure for better sensitivity and shorter response times.

Polarographic carbon dioxide transducer amplifier

NASA Technical Reports Server (NTRS)

Stillman, G.

1971-01-01

Electronic amplifier contains matched pair of metal oxide semiconductor field effect transistor devices which have high input impedance and long-term stability. Thermistor in feedback loop provides temperature compensation for large drifts in the sensor.

CO2 Sensors Based on Nanocrystalline SnO2 Doped with CuO

NASA Technical Reports Server (NTRS)

Xu, Jennifer C.; Hunter, Gary W.; Liu, Chung Chiun; Ward, Benjamin J.

2008-01-01

Nanocrystalline tin oxide (SnO2) doped with copper oxide (CuO) has been found to be useful as an electrical-resistance sensory material for measuring the concentration of carbon dioxide in air. SnO2 is an n-type semiconductor that has been widely used as a sensing material for detecting such reducing gases as carbon monoxide, some of the nitrogen oxides, and hydrocarbons. Without doping, SnO2 usually does not respond to carbon dioxide and other stable gases. The discovery that the electrical resistance of CuO-doped SnO2 varies significantly with the concentration of CO2 creates opportunities for the development of relatively inexpensive CO2 sensors for detecting fires and monitoring atmospheric conditions. This discovery could also lead to research that could alter fundamental knowledge of SnO2 as a sensing material, perhaps leading to the development of SnO2-based sensing materials for measuring concentrations of oxidizing gases. Prototype CO2 sensors based on CuO-doped SnO2 have been fabricated by means of semiconductor-microfabrication and sol-gel nanomaterial-synthesis batch processes that are amendable to inexpensive implementation in mass production.

Compensated infrared absorption sensor for carbon dioxide and other infrared absorbing gases

DOEpatents

Owen, Thomas E.

2005-11-29

A gas sensor, whose chamber uses filters and choppers in either a semicircular geometry or annular geometry, and incorporates separate infrared radiation filters and optical choppers. This configuration facilitates the use of a single infrared radiation source and a single detector for infrared measurements at two wavelengths, such that measurement errors may be compensated.

Current and emerging laser sensors for greenhouse gas sensing and leak detection

NASA Astrophysics Data System (ADS)

Frish, Michael B.

2014-05-01

To reduce atmospheric accumulation of the greenhouse gases methane and carbon dioxide, networks of continuously operating sensors that monitor and map their sources are desirable. In this paper, we discuss advances in laser-based open-path leak detectors, as well as technical and economic challenges inhibiting widespread sensor deployment for "ubiquitous monitoring". We describe permanently-installed, wireless, solar-powered sensors that overcome previous installation and maintenance difficulties while providing autonomous real-time leak reporting without false alarms.

Development of Photoacoustic Sensing Platforms at the US Army Research Laboratory

DTIC Science & Technology

2016-09-01

RDX and TNT explosives with carbon dioxide laser. J Appl Spectrosc. 2006;73(1):123–129. 45. Petzold A, Niessner R. Photoacoustic soot sensor for in...Development of Photoacoustic Sensing Platforms at the US Army Research Laboratory by Ellen L Holthoff and Paul M Pellegrino Sensors and Electron Devices...NOTES 14. ABSTRACT Traditionally, chemical sensing platforms have been hampered by the opposing concerns of increasing sensor capability while

Carbon Dioxide Observational Platform System (CO-OPS), feasibility study

NASA Technical Reports Server (NTRS)

Bouquet, D. L.; Hall, D. W.; Mcelveen, R. P.

1987-01-01

The Carbon Dioxide Observational Platform System (CO-OPS) is a near-space, geostationary, multi-user, unmanned microwave powered monitoring platform system. This systems engineering feasibility study addressed identified existing requirements such as: carbon dioxide observational data requirements, communications requirements, and eye-in-the-sky requirements of other groups like the Defense Department, the Forestry Service, and the Coast Guard. In addition, potential applications in: earth system science, space system sciences, and test and verification (satellite sensors and data management techniques) were considered. The eleven month effort is summarized. Past work and methods of gathering the required observational data were assessed and rough-order-of magnitude cost estimates have shown the CO-OPS system to be most cost effective (less than $30 million within a 10 year lifetime). It was also concluded that there are no technical, schedule, or obstacles that would prevent achieving the objectives of the total 5-year CO-OPS program.

Near-Simultaneous Measurement of Ground Level Carbon Dioxide and Methane Concentrations with an Open-Path Tunable Diode Laser Sensor at the Bonanza Creek Long Term Ecological Research site near Fairbanks, Alaska

NASA Astrophysics Data System (ADS)

Bailey, D. M.; Miller, J. H. H.

2017-12-01

Beyond anthropogenic carbon emissions, the increase in atmospheric carbon from natural feedbacks such as thawing permafrost poses a risk to the global climate as global temperatures continue to increase. Permafrost is formally defined as soil that is continuously frozen for 24 consecutive months. These soils comprise nearly twenty-five percent of the Earth's terrestrial surface and possess twice the amount of carbon currently in the atmosphere. Continuous collection of carbon dioxide (CO2) and methane (CH4) concentrations is imperative in understanding seasonal and inter-annual variability of carbon feedbacks above thawing permafrost. A multi-year collaborative effort with the University of Alaska - Fairbanks, NASA Goddard Space Flight Center, and our group at George Washington University is underway to monitor these feedbacks near Fairbanks, Alaska. In June 2017, we deployed two open-path tunable diode laser sensors at the Bonanza Long Term Ecological Research Site for measurement of CO2 and CH4 concentrations. The open-path instrument (OPI) is an inexpensive, low-power sensor that collects spatially-integrated measurements of target molecules approximately 1.5 meters above ground level. With a total power burden of 18 W, the sensors ran exclusively on solar power for 15 days in a young thermokarst bog and 3.5 days at a rich fen site. Here we report on initial retrieval of diurnal cycles from each field site and compare our spatially-integrated measurements of CO2 and CH4. For CO2, the magnitude of the diurnal cycles show a strong dependence on daily weather at both field sites. These laser measurements are complemented by point measurements of CO2, temperature, pressure, and humidity made along the laser's optical path by non-dispersive infrared (NDIR) sensors.

Development of indoor environmental index: Air quality index and thermal comfort index

NASA Astrophysics Data System (ADS)

Saad, S. M.; Shakaff, A. Y. M.; Saad, A. R. M.; Yusof, A. M.; Andrew, A. M.; Zakaria, A.; Adom, A. H.

2017-03-01

In this paper, index for indoor air quality (also known as IAQI) and thermal comfort index (TCI) have been developed. The IAQI was actually modified from previous outdoor air quality index (AQI) designed by the United States Environmental Protection Agency (US EPA). In order to measure the index, a real-time monitoring system to monitor indoor air quality level was developed. The proposed system consists of three parts: sensor module cloud, base station and service-oriented client. The sensor module cloud (SMC) contains collections of sensor modules that measures the air quality data and transmit the captured data to base station through wireless. Each sensor modules includes an integrated sensor array that can measure indoor air parameters like Carbon Dioxide, Carbon Monoxide, Ozone, Nitrogen Dioxide, Oxygen, Volatile Organic Compound and Particulate Matter. Temperature and humidity were also being measured in order to determine comfort condition in indoor environment. The result from several experiments show that the system is able to measure the air quality presented in IAQI and TCI in many indoor environment settings like air-conditioner, chemical present and cigarette smoke that may impact the air quality. It also shows that the air quality are changing dramatically, thus real-time monitoring system is essential.

Supercritical carbon dioxide-assisted rapid synthesis of few-layer black phosphorus for hydrogen peroxide sensing.

PubMed

Yan, Shancheng; Wang, Bojun; Wang, Zhulan; Hu, Dong; Xu, Xin; Wang, Junzhuan; Shi, Yi

2016-06-15

Solutions with large-scale dispersions of 2D black phosphorus (BP), often referred to as phosphorene, are obtained through solvent exfoliation. But, rapid phosphorene synthesis remains a challenge. Furthermore, although the chemical sensing capability of BP-based sensors has been theoretically predicted, its experimental verification remains lacking. In this study, we demonstrate the use of supercritical carbon dioxide-assisted rapid synthesis (5h) of few-layer BP. In addition, we construct a non-enzymatic hydrogen peroxide (H2O2) sensor based on few-layer BP for the first time to utilize BP degradation under ambient conditions. The proposed H2O2 sensor exhibits a considerably lower detection limit of 1 × 10(-7) M compared with the general detection limit of 1 × 10(-7) M-5 × 10(-5)M via electrochemical methods. Overall, the results of this study will not only expand the coverage of BP research but will also identify the important sensing characteristics of BP. Copyright © 2016 Elsevier B.V. All rights reserved.

Zeolitic imidazolate framework-coated acoustic sensors for room temperature detection of carbon dioxide and methane

DOE PAGES

Devkota, Jagannath; Kim, Ki-Joong; Ohodnicki, Paul R.; ...

2018-01-01

The integration of nanoporous materials such as metal organic frameworks (MOFs) with sensitive transducers can result in robust sensing platforms for monitoring gases and chemical vapors for a range of applications.

Gas sensing with gold-decorated vertically aligned carbon nanotubes

PubMed Central

Mudimela, Prasantha R; Scardamaglia, Mattia; González-León, Oriol; Reckinger, Nicolas; Snyders, Rony; Llobet, Eduard; Colomer, Jean-François

2014-01-01

Summary Vertically aligned carbon nanotubes of different lengths (150, 300, 500 µm) synthesized by thermal chemical vapor deposition and decorated with gold nanoparticles were investigated as gas sensitive materials for detecting nitrogen dioxide (NO2) at room temperature. Gold nanoparticles of about 6 nm in diameter were sputtered on the top surface of the carbon nanotube forests to enhance the sensitivity to the pollutant gas. We showed that the sensing response to nitrogen dioxide depends on the nanotube length. The optimum was found to be 300 µm for getting the higher response. When the background humidity level was changed from dry to 50% relative humidity, an increase in the response to NO2 was observed for all the sensors, regardless of the nanotube length. PMID:24991529

Gas sensing with gold-decorated vertically aligned carbon nanotubes.

PubMed

Mudimela, Prasantha R; Scardamaglia, Mattia; González-León, Oriol; Reckinger, Nicolas; Snyders, Rony; Llobet, Eduard; Bittencourt, Carla; Colomer, Jean-François

2014-01-01

Vertically aligned carbon nanotubes of different lengths (150, 300, 500 µm) synthesized by thermal chemical vapor deposition and decorated with gold nanoparticles were investigated as gas sensitive materials for detecting nitrogen dioxide (NO2) at room temperature. Gold nanoparticles of about 6 nm in diameter were sputtered on the top surface of the carbon nanotube forests to enhance the sensitivity to the pollutant gas. We showed that the sensing response to nitrogen dioxide depends on the nanotube length. The optimum was found to be 300 µm for getting the higher response. When the background humidity level was changed from dry to 50% relative humidity, an increase in the response to NO2 was observed for all the sensors, regardless of the nanotube length.

Projected effects of vegetation and organic matter on soil carbon dynamics after rainfall in a model basalt landscape.

NASA Astrophysics Data System (ADS)

Van Haren, J. L. M.; Sanchez-Canete, E. P.; Juarez, S.; Howard, E. L.; Dontsova, K.; Le Galliard, J. F.; Barron-Gafford, G.; Volkmann, T.; Troch, P. A.

2017-12-01

Basalt is one of the most important rock types in controlling atmospheric carbon dioxide concentrations on a geologic scale. At the University of Arizona's Biosphere 2 facility, we have built the world's largest geological model system - the Landscape Evolution Observatory (LEO) - to determine the hydrological and biogeochemical changes before and after the addition of plants. LEO consists of three 30x11 m and 1-m deep hillslope landscapes of basaltic tephra ground to homogenous loamy sand inside an environmentally controlled facility. Each landscape contains a sensor network capable of capturing water, carbon, and energy cycling processes at 15-min resolution and sub-meter to whole-landscape scales. At LEO, we measured the soil carbon dynamics in bare soil, with only minimal biological activity, after multiple rainfall events. These measurements consistently showed that rainfall, soil moisture, and soil gas diffusion are strong drivers of carbon uptake in a porous basalt matrix. Our expectation is that the addition of plants will dramatically change the carbon dynamics following rainfall events and produce Birch-effect-like pulses of carbon dioxide following rainfall events. We tested this prediction in smaller-scale and shorter-term experiments done at the CEREEP-ECOTRON lab in Ile de France, France, where we experimented with three different plant species grown in the same LEO soil. Soil carbon responses were similar to the LEO slope irrespective of whether plants were grown in the soil: initial wetting leads to a strong drawdown of carbon dioxide in the soil. However, due to plant activity, the soil carbon dioxide concentration recovered faster in the basalt soil when plants were present. Only in small scale incubations with a mixture of LEO soil with an organic-rich (6.5% carbon) prairie soil did we see the expected pulse of carbon dioxide following the addition of water. The smaller-scale experiments suggest that the occurrence of carbon dioxide fluxes generated by rainfall events will not occur after the addition of plants, but will depend on the development of an organic horizon within the LEO soil.

In situ spectrophotometric measurement of dissolved inorganic carbon in seawater.

PubMed

Liu, Xuewu; Byrne, Robert H; Adornato, Lori; Yates, Kimberly K; Kaltenbacher, Eric; Ding, Xiaoling; Yang, Bo

2013-10-01

Autonomous in situ sensors are needed to document the effects of today's rapid ocean uptake of atmospheric carbon dioxide (e.g., ocean acidification). General environmental conditions (e.g., biofouling, turbidity) and carbon-specific conditions (e.g., wide diel variations) present significant challenges to acquiring long-term measurements of dissolved inorganic carbon (DIC) with satisfactory accuracy and resolution. SEAS-DIC is a new in situ instrument designed to provide calibrated, high-frequency, long-term measurements of DIC in marine and fresh waters. Sample water is first acidified to convert all DIC to carbon dioxide (CO2). The sample and a known reagent solution are then equilibrated across a gas-permeable membrane. Spectrophotometric measurement of reagent pH can thereby determine the sample DIC over a wide dynamic range, with inherent calibration provided by the pH indicator's molecular characteristics. Field trials indicate that SEAS-DIC performs well in biofouling and turbid waters, with a DIC accuracy and precision of ∼2 μmol kg(-1) and a measurement rate of approximately once per minute. The acidic reagent protects the sensor cell from biofouling, and the gas-permeable membrane excludes particulates from the optical path. This instrument, the first spectrophotometric system capable of automated in situ DIC measurements, positions DIC to become a key parameter for in situ CO2-system characterizations.

Evolution of Space Station EMU PLSS technology recommendations

NASA Technical Reports Server (NTRS)

Wilde, Richard C.

1990-01-01

Viewgraphs on extravehicular mobility unit (EMU) portable life support system (PLSS) technology recommendations are presented. Topics covered include: oxygen supply storage; oxygen supply regulators; carbon dioxide control; prime movers; crew comfort; heat rejection; power sources; controls; display devices; and sensor technology.

The Application of Metal Oxide Nanomaterials for Chemical Sensor Development

NASA Technical Reports Server (NTRS)

Xu, Jennifer C.; Hunter, Gary W.; Evans, Laura J.; VanderWal, Randy L.; Berger, Gordon M.

2007-01-01

NASA Glenn Research Center (GRC) has been developing miniature chemical sensors for a variety of applications including fire detection, emissions monitoring, fuel leak detection, and environmental monitoring. Smart Lick and Stick sensor technology which integrates a sensor array, electronics, telemetry, and power into one microsystem are being developed. These microsystems require low power consumption for long-term aerospace applications. One approach to decreasing power consumption is the use of nanotechnology. Nanocrystalline tin oxide (SnO2) carbon monoxide (CO) sensors developed previously by this group have been successfully used for fire detection and emissions monitoring. This presentation will briefly review the overall NASA GRC chemical sensor program and discuss our further effort in nanotechnology applications. New carbon dioxide (CO2) sensing material using doped nanocrystalline SnO2 will be discussed. Nanocrystalline SnO2 coated solid electrolyte CO2 sensors and SnO2 nanorod and nanofiber hydrogen (H2) sensors operated at reduced or room temperatures will also be discussed.

Advancement of Miniature Optic Gas Sensor (MOGS) Probe Technology

NASA Technical Reports Server (NTRS)

Chullen, Cinda

2015-01-01

Advancement of Miniature Optic Gas Sensor (MOGS) Probe Technology" project will investigate newly developed optic gas sensors delivered from a Small Business Innovative Research (SBIR) Phase II effort. A ventilation test rig will be designed and fabricated to test the sensors while integrated with a Suited Manikin Test Apparatus (SMTA). Once the sensors are integrated, a series of test points will be completed to verify that the sensors can withstand Advanced Suit Portable Life Support System (PLSS) environments and associated human metabolic profiles for changes in pressure and levels of Oxygen (ppO2), carbon dioxide (ppCO2), and humidity (ppH2O).

Microfabricated Chemical Gas Sensors and Sensor Arrays for Aerospace Applications

NASA Technical Reports Server (NTRS)

Hunter, Gary W.

2005-01-01

Aerospace applications require the development of chemical sensors with capabilities beyond those of commercially available sensors. In particular, factors such as minimal sensor size, weight, and power consumption are particularly important. Development areas which have potential aerospace applications include launch vehicle leak detection, engine health monitoring, and fire detection. Sensor development for these applications is based on progress in three types of technology: 1) Micromachining and microfabrication (Microsystem) technology to fabricate miniaturized sensors; 2) The use of nanocrystalline materials to develop sensors with improved stability combined with higher sensitivity; 3) The development of high temperature semiconductors, especially silicon carbide. This presentation discusses the needs of space applications as well as the point-contact sensor technology and sensor arrays being developed to address these needs. Sensors to measure hydrogen, hydrocarbons, nitrogen oxides (NO,), carbon monoxide, oxygen, and carbon dioxide are being developed as well as arrays for leak, fire, and emissions detection. Demonstrations of the technology will also be discussed. It is concluded that microfabricated sensor technology has significant potential for use in a range of aerospace applications.

Oxygen sensor via the quenching of room-temperature phosphorescence of perdeuterated phenanthrene adsorbed on Whatman 1PS filter paper.

PubMed

Ramasamy, S M; Hurtubise, R J

1998-11-01

Perdeuterated phenanthrene (d-phen) exhibits strong room-temperature phosphorescence (RTP) when adsorbed on Whatman 1PS filter paper. An oxygen sensor was developed that depends on oxygen quenching of RTP intensity of adsorbed d-phen. The system designed employed a continuous flow of nitrogen or nitrogen-air onto the adsorbed phosphor. The sensor is simple to prepare and needs no elaborate fabrication procedure, but did show a somewhat drifting baseline for successive determinations of oxygen. Nevertheless, very good reproducibility was achieved with the RTP quenching data by measuring the RTP intensities just before and at the end of each oxygen determination. The calibration plots gave a nonlinear relationship over the entire range of oxygen (0-21%). However, a linear range was obtained up to 1.10% oxygen. A detection limit of 0.09% oxygen in dry nitrogen was acquired. Also, carbon dioxide was found to have a minimal effect on the RTP quenching. Thus, oxygen could be measured accurately in relatively large amounts of carbon dioxide. The performance of the oxygen sensor was evaluated by comparing data obtained with a commercial electrochemical trace oxygen analyzer. Also, additional information on the quenching phenomena for this system was obtained from the RTP lifetime data acquired at various oxygen contents.

DEVELOPMENT OF A LOW-COST INFERENTIAL NATURAL GAS ENERGY FLOW RATE PROTOTYPE RETROFIT MODULE

DOE Office of Scientific and Technical Information (OSTI.GOV)

E. Kelner; T.E. Owen; D.L. George

2004-03-01

In 1998, Southwest Research Institute{reg_sign} began a multi-year project co-funded by the Gas Research Institute (GRI) and the U.S. Department of Energy. The project goal is to develop a working prototype instrument module for natural gas energy measurement. The module will be used to retrofit a natural gas custody transfer flow meter for energy measurement, at a cost an order of magnitude lower than a gas chromatograph. Development and evaluation of the prototype retrofit natural gas energy flow meter in 2000-2001 included: (1) evaluation of the inferential gas energy analysis algorithm using supplemental gas databases and anticipated worst-case gas mixtures;more » (2) identification and feasibility review of potential sensing technologies for nitrogen diluent content; (3) experimental performance evaluation of infrared absorption sensors for carbon dioxide diluent content; and (4) procurement of a custom ultrasonic transducer and redesign of the ultrasonic pulse reflection correlation sensor for precision speed-of-sound measurements. A prototype energy meter module containing improved carbon dioxide and speed-of-sound sensors was constructed and tested in the GRI Metering Research Facility at SwRI. Performance of this module using transmission-quality natural gas and gas containing supplemental carbon dioxide up to 9 mol% resulted in gas energy determinations well within the inferential algorithm worst-case tolerance of {+-}2.4 Btu/scf (nitrogen diluent gas measured by gas chromatograph). A two-week field test was performed at a gas-fired power plant to evaluate the inferential algorithm and the data acquisition requirements needed to adapt the prototype energy meter module to practical field site conditions.« less

Fabrication and evaluation of polymeric early-warning fire-alarm devices. [combustion products

NASA Technical Reports Server (NTRS)

Senturia, S. D.

1975-01-01

The electrical resistivities were investigated of some polymers known to be enhanced by the presence of certain gases. This was done to make a device capable of providing early warning to fire through its response with the gases produced in the early phases of combustion. Eight polymers were investigated: poly(phenyl acetylene), poly(p-aminophenyl acetylene), poly(p-nitrophenyl acetylene), poly(p-formamidophenyl acetylene), poly(ethynyl ferrocene), poly(ethynyl carborane), poly(ethynyl pyridine), and the polymer made from 1,2,3,6 tetramethyl pyridazine. A total of 40 usable thin-film sandwich devices and a total of 70 usable interdigitated-electrode lock-and-key devices were fabricated. The sandwich devices were used for measurements of contact linearity, polymer conductivity, and polymer dielectric constant. The lock-and-key devices were used to determine the response of the polymers to a spectrum of gases that included ammonia, carbon nonoxide, carbon dioxide, sulfur dioxide, ethylene, acrolein, water vapor, and normal laboratory air. Strongest responses were to water vapor, ammonia, and acrolein, and depending on the polymer, weaker responses to carbon dioxide, sulfur dioxide, and carbon monoxide were observed. A quantitative theory of device operation, capable of accounting for observed device leakage current and sensitivity, was developed. A prototype detection/alarm system was designed and built for use in demonstrating sensor performance.

Active polymer materials for optical fiber CO2 sensors

NASA Astrophysics Data System (ADS)

Wysokiński, Karol; Filipowicz, Marta; Stańczyk, Tomasz; Lipiński, Stanisław; Napierała, Marek; Murawski, Michał; Nasiłowski, Tomasz

2017-04-01

CO2 optical fiber sensors based on polymer active materials are presented in this paper. Ethyl cellulose was proven to be a good candidate for a matrix material of the sensor, since it gives porous, thick and very sensitive layers. Low-cost sensors based on polymer optical fibers have been elaborated. Sensors have been examined for their sensitivity to CO2, temperature and humidity. Response time during cyclic exposures to CO2 have been also determined. Special layers exhibiting irreversible change of color during exposure to carbon dioxide have been developed. They have been verified for a possible use in smart food packaging.

CO2 sensing properties of electro-spun Ca-doped ZnO fibres.

PubMed

Pantò, Fabiola; Leonardi, Salvatore Gianluca; Fazio, Enza; Frontera, Patrizia; Bonavita, Anna; Neri, Giovanni; Antonucci, Pierluigi; Neri, Fortunato; Santangelo, Saveria

2018-07-27

The availability of low-cost, high-performing sensors for carbon dioxide detection in the environment may play a crucial role for reducing CO 2 emissions and limiting global warming. In this study, calcium-doped zinc oxide nanofibres with different Ca to Zn loading ratios (1:40 or 1:20) are synthesised via electro-spinning, thoroughly characterised and, for the first time, tested as an active material for the detection of carbon dioxide. The results of their characterisation show that the highly porous fibres consist of interconnected grains of oxide with the hexagonal wurtzite structure of zincite. Depending on the Ca:Zn loading ratio, calcium fully or partly segregates to form calcite on the fibre surface. The high response of the sensor based on the fibres with the highest Ca-doping level can be attributed to the synergy between the fibre morphology and the basicity of Ca-ion sites, which favour the diffusion of the gas molecules within the sensing layer and the CO 2 adsorption, respectively.

Advantages of electrodes with dendrimer-protected platinum nanoparticles and carbon nanotubes for electrochemical methanol oxidation.

PubMed

Siriviriyanun, Ampornphan; Imae, Toyoko

2013-04-14

Electrochemical sensors consisting of electrodes loaded with carbon nanotubes and Pt nanoparticles (PtNPs) protected by dendrimers have been developed using a facile method to fabricate them on two types of disposable electrochemical printed chips with a screen-printed circular gold or a screen-printed circular glassy carbon working electrode. The electrochemical performance of these sensors in the oxidation of methanol was investigated by cyclic voltammetry. It was revealed that such sensors possess stable durability and high electrocatalytic activity: the potential and the current density of an anodic peak in the oxidation of methanol increased with increasing content of PtNPs on the electrodes, indicating the promotion of electrocatalytic activity in relation to the amount of catalyst. The low anodic potential suggests the easy electrochemical reaction, and the high catalyst tolerance supports the almost complete oxidation of methanol to carbon dioxide. The significant performance of these sensors in the detection of methanol oxidation comes from the high electrocatalytic ability of PtNPs, excellent energy transfer of carbon nanotubes and the remarkable ability of dendrimers to act as binders. Thus these systems are effective for a wide range of applications as chemical, biomedical, energy and environmental sensors and as units of direct methanol fuel cells.

Effect of electrode gap on the sensing properties of multiwalled carbon nanotubes based gas sensor

NASA Astrophysics Data System (ADS)

Saheed, Mohamed Shuaib Mohamed; Mohamed, Norani Muti; Burhanudin, Zainal Arif

2016-11-01

Vertically aligned multiwalled carbon nanotubes (MWCNT) were grown on Si substrate coated with alumina and iron using chemical vapor deposition. Electrode gap of 10, 25 and 50 µm were adopted to determine the effect of varying gap spacing on the sensing properties such as voltage breakdown, sensitivity and selectivity for three gases namely argon, carbon dioxide and ammonia. Argon has the lowest voltage breakdown for every electrode gap. The fabricated MWCNT based gas sensor drastically reduced the voltage breakdown by 89.5% when the electrode spacing is reduced from 50 µm to 10 µm. The reduction is attributed to the high non-uniform electric field between the electrodes caused by the protrusion of nanotips. The sensor shows good sensitivity and selectivity with the ability to detect the gas in the mixture with air provided that the concentration is ≥ 20% where the voltage breakdown will be close to the pure gas.

Ultra-bright red-emitting photostable perylene bisimide dyes: new indicators for ratiometric sensing of high pH or carbon dioxide.

PubMed

Pfeifer, David; Klimant, Ingo; Borisov, Sergey M

2018-05-08

New pH sensitive perylene bisimide indicator dyes were synthesised and used for fabrication of optical sensors. The highly photostable dyes show absorption/emission bands in the red/near-infrared (NIR) region of the electromagnetic spectrum, high molar absorption coefficients (up to 100 000 M-1 cm-1) and fluorescence quantum yields close to unity. The absorption and emission spectra show strong bathochromic shift upon deprotonation of imidazole nitrogen which makes the dyes promising as ratiometric fluorescent indicators. Physical entrapment of the indicators into polyurethane hydrogel enables pH determination in alkaline pH. It is also shown that plastic carbon dioxide solid state sensor can be manufactured via immobilization of the pH indicator in a hydrophilic polymer, along with a quaternary ammonium base. The influence of plasticizer, different lipophilic bases and humidity on the sensitivity of the sensor material were systematically investigated. The disubstituted perylene, particularly, features two deprotonation equilibria enabling sensing over a very broad range from 0.5 to 1000 hPa pCO2. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characteristics of urban-ecosystem atmosphere fluxes of CO2, CH4, N2O, and et over Denver, Colorado

USGS Publications Warehouse

Anderson, D.E.; Alvarez, C.; Thienelt, T.

2004-01-01

The characteristics of urban ecosystems fluxes of carbon dioxide, methane, nitrous oxide, and evapotranspiration (ET) over Denver, Colorado were discussed. These atmospheric fluxes were measured using a methodology that included a combination of eddy covariance sensors at two levels on a tall tower and chamber measurements at 33 locations on the soil surface. There was both strong temporal and spatial heterogeneity of fluxes owing to characteristics of natural and anthropogenic ecosystem components. Although the urban ecosystem was a net carbon dioxide source, tower-based eddy covariance measurements showed it to be a net vegetative sink during the majority of mid-say summer hours.

Development of a Contingency Gas Analyzer for the Orion Crew Exploration Vehicle

NASA Technical Reports Server (NTRS)

Niu, Bill; Carney, Kenneth; Steiner, George; OHarra, William; Lewis, John

2010-01-01

NASA's experience with electrochemical sensors in a hand-held toxic gas monitor serves as a basis for the development of a fixed on-board instrument, the Contingency Gas Analyzer (CGA), for monitoring selected toxic combustion products as well as oxygen and carbon dioxide on the Orion Crew Exploration Vehicle (CEV). Oxygen and carbon dioxide are major components of the cabin environment and accurate measurement of these compounds is critical to maintaining a safe working environment for the crew. Fire or thermal degradation events may produce harmful levels of toxic products, including carbon monoxide (CO), hydrogen cyanide (HCN), and hydrogen chloride (HCl) in the environment. These three components, besides being toxic in their own right, can serve as surrogates for a panoply of hazardous combustion products. On orbit monitoring of these surrogates provides for crew health and safety by indicating the presence of toxic combustion products in the environment before, during and after combustion or thermal degradation events. Issues identified in previous NASA experiences mandate hardening the instrument and components to endure the mechanical and operational stresses of the CEV environment while maintaining high analytical fidelity. Specific functional challenges involve protecting the sensors from various anticipated events- such as rapid pressure changes, low cabin pressures, and extreme vibration/shock exposures- and extending the sensor lifetime and calibration periods far beyond the current state of the art to avoid the need for on-orbit calibration. This paper focuses on lessons learned from the earlier NASA hardware, current testing results, and engineering solutions to the identified problems. Of particular focus will be the means for protecting the sensors, addressing well known cross-sensitivity issues and the efficacy of a novel self monitoring mechanism for extending sensor calibration periods.

Using a Datalogger to Determine First-Order Kinetics and Calcium Carbonate in Eggshells

ERIC Educational Resources Information Center

Choi, Martin M. F.; Pui Shan Wong

2004-01-01

The applications of a Pasco CI-6532 pressure sensor used in conjunction with a datalogger to monitor the liberation of carbon dioxide in the reaction CaCO3(s) + 2H(super +)(aq) --> Ca(super 2+)(aq) + CO2 (g) + H2O(I) are described. The method serves for the determination of the chemical kinetics of the reaction and also can be extended to…

Solid State Carbon Monoxide Sensor

NASA Technical Reports Server (NTRS)

Upchurch, Billy T. (Inventor); Wood, George M. (Inventor); Schryer, David R. (Inventor); Leighty, Bradley D. (Inventor); Oglesby, Donald M. (Inventor); Kielin, Erik J. (Inventor); Brown, Kenneth G. (Inventor); DAmbrosia, Christine M. (Inventor)

1999-01-01

A means for detecting carbon monoxide which utilizes an un-heated catalytic material to oxidize carbon monoxide at ambient temperatures. Because this reaction is exothermic, a thermistor in contact with the catalytic material is used as a sensing element to detect the heat evolved as carbon monoxide is oxidized to carbon dioxide at the catalyst surface, without any heaters or external heating elements for the ambient air or catalytic element material. Upon comparison to a reference thermistor, relative increases in the temperature of the sensing thermistor correspond positively with an increased concentration of carbon monoxide in the ambient medium and are thus used as an indicator of the presence of carbon monoxide.

In situ spectrophotometric measurement of dissolved inorganic carbon in seawater

USGS Publications Warehouse

Liua, Xuewu; Byrne, Robert H.; Adornato, Lori; Yates, Kimberly K.; Kaltenbacher, Eric; Ding, Xiaoling; Yang, Bo

2013-01-01

Autonomous in situ sensors are needed to document the effects of today’s rapid ocean uptake of atmospheric carbon dioxide (e.g., ocean acidification). General environmental conditions (e.g., biofouling, turbidity) and carbon-specific conditions (e.g., wide diel variations) present significant challenges to acquiring long-term measurements of dissolved inorganic carbon (DIC) with satisfactory accuracy and resolution. SEAS-DIC is a new in situ instrument designed to provide calibrated, high-frequency, long-term measurements of DIC in marine and fresh waters. Sample water is first acidified to convert all DIC to carbon dioxide (CO2). The sample and a known reagent solution are then equilibrated across a gas-permeable membrane. Spectrophotometric measurement of reagent pH can thereby determine the sample DIC over a wide dynamic range, with inherent calibration provided by the pH indicator’s molecular characteristics. Field trials indicate that SEAS-DIC performs well in biofouling and turbid waters, with a DIC accuracy and precision of ∼2 μmol kg–1 and a measurement rate of approximately once per minute. The acidic reagent protects the sensor cell from biofouling, and the gas-permeable membrane excludes particulates from the optical path. This instrument, the first spectrophotometric system capable of automated in situ DIC measurements, positions DIC to become a key parameter for in situ CO2-system characterizations.

Community Air Sensor Network (CAIRSENSE) project: evaluation of low-cost sensor performance in a suburban environment in the southeastern United States

NASA Astrophysics Data System (ADS)

Jiao, Wan; Hagler, Gayle; Williams, Ronald; Sharpe, Robert; Brown, Ryan; Garver, Daniel; Judge, Robert; Caudill, Motria; Rickard, Joshua; Davis, Michael; Weinstock, Lewis; Zimmer-Dauphinee, Susan; Buckley, Ken

2016-11-01

Advances in air pollution sensor technology have enabled the development of small and low-cost systems to measure outdoor air pollution. The deployment of a large number of sensors across a small geographic area would have potential benefits to supplement traditional monitoring networks with additional geographic and temporal measurement resolution, if the data quality were sufficient. To understand the capability of emerging air sensor technology, the Community Air Sensor Network (CAIRSENSE) project deployed low-cost, continuous, and commercially available air pollution sensors at a regulatory air monitoring site and as a local sensor network over a surrounding ˜ 2 km area in the southeastern United States. Collocation of sensors measuring oxides of nitrogen, ozone, carbon monoxide, sulfur dioxide, and particles revealed highly variable performance, both in terms of comparison to a reference monitor as well as the degree to which multiple identical sensors produced the same signal. Multiple ozone, nitrogen dioxide, and carbon monoxide sensors revealed low to very high correlation with a reference monitor, with Pearson sample correlation coefficient (r) ranging from 0.39 to 0.97, -0.25 to 0.76, and -0.40 to 0.82, respectively. The only sulfur dioxide sensor tested revealed no correlation (r < 0.5) with a reference monitor and erroneously high concentration values. A wide variety of particulate matter (PM) sensors were tested with variable results - some sensors had very high agreement (e.g., r = 0.99) between identical sensors but moderate agreement with a reference PM2.5 monitor (e.g., r = 0.65). For select sensors that had moderate to strong correlation with reference monitors (r > 0.5), step-wise multiple linear regression was performed to determine if ambient temperature, relative humidity (RH), or age of the sensor in number of sampling days could be used in a correction algorithm to improve the agreement. Maximum improvement in agreement with a reference, incorporating all factors, was observed for an NO2 sensor (multiple correlation coefficient R2adj-orig = 0.57, R2adj-final = 0.81); however, other sensors showed no apparent improvement in agreement. A four-node sensor network was successfully able to capture ozone (two nodes) and PM (four nodes) data for an 8-month period of time and show expected diurnal concentration patterns, as well as potential ozone titration due to nearby traffic emissions. Overall, this study demonstrates the performance of emerging air quality sensor technologies in a real-world setting; the variable agreement between sensors and reference monitors indicates that in situ testing of sensors against benchmark monitors should be a critical aspect of all field studies.

Airborne Detection and Dynamic Modeling of Carbon Dioxide and Methane Plumes

NASA Astrophysics Data System (ADS)

Jacob, Jamey; Mitchell, Taylor; Whyte, Seabrook

2015-11-01

To facilitate safe storage of greenhouse gases such as CO2 and CH4, airborne monitoring is investigated. Conventional soil gas monitoring has difficulty in distinguishing gas flux signals from leakage with those associated with meteorologically driven changes. A low-cost, lightweight sensor system has been developed and implemented onboard a small unmanned aircraft that measures gas concentration and is combined with other atmospheric diagnostics, including thermodynamic data and velocity from hot-wire and multi-hole probes. To characterize the system behavior and verify its effectiveness, field tests have been conducted over controlled rangeland burns and over simulated leaks. In the former case, since fire produces carbon dioxide over a large area, this was an opportunity to test in an environment that while only vaguely similar to a carbon sequestration leak source, also exhibits interesting plume behavior. In the simulated field tests, compressed gas tanks are used to mimic leaks and generate gaseous plumes. Since the sensor response time is a function of vehicle airspeed, dynamic calibration models are required to determine accurate location of gas concentration in (x , y , z , t) . Results are compared with simulations using combined flight and atmospheric dynamic models. Supported by Department of Energy Award DE-FE0012173.

Metrological traceability of carbon dioxide measurements in atmosphere and seawater

NASA Astrophysics Data System (ADS)

Rolle, F.; Pessana, E.; Sega, M.

2017-05-01

The accurate determination of gaseous pollutants is fundamental for the monitoring of the trends of these analytes in the environment and the application of the metrological concepts to this field is necessary to assure the reliability of the measurement results. In this work, an overview of the activity carried out at Istituto Nazionale di Ricerca Metrologica to establish the metrological traceability of the measurements of gaseous atmospheric pollutants, in particular of carbon dioxide (CO2), is presented. Two primary methods, the gravimetry and the dynamic dilution, are used for the preparation of reference standards for composition which can be used to calibrate sensors and analytical instrumentation. At present, research is carried out to lower the measurement uncertainties of the primary gas mixtures and to extend their application to the oceanic field. The reason of such investigation is due to the evidence of the changes occurring in seawater carbonate chemistry, connected to the rising level of CO2 in the atmosphere. The well established activity to assure the metrological traceability of CO2 in the atmosphere will be applied to the determination of CO2 in seawater, by developing suitable reference materials for calibration and control of the sensors during their routine use.

Sorption Behavior of Compressed CO2 and CH4 on Ultrathin Hybrid Poly(POSS-imide) Layers.

PubMed

Raaijmakers, Michiel J T; Ogieglo, Wojciech; Wiese, Martin; Wessling, Matthias; Nijmeijer, Arian; Benes, Nieck E

2015-12-09

Sorption of compressed gases into thin polymeric films is essential for applications including gas sensors and membrane based gas separation. For glassy polymers, the sorption behavior is dependent on the nonequilibrium status of the polymer. The uptake of molecules by a polymer is generally accompanied by dilation, or swelling, of the polymer material. In turn, this dilation can result in penetrant induced plasticization and physical aging that affect the nonequilibrium status of the polymer. Here, we investigate the dilation and sorption behavior of ultrathin membrane layers of a hybrid inorganic-organic network material that consists of alternating polyhedral oligomeric silsesquioxane and imide groups, upon exposure to compressed carbon dioxide and methane. The imide precursor contains fluoroalkene groups that provide affinity toward carbon dioxide, while the octa-functionalized silsesquioxane provides a high degree of cross-linking. This combination allows for extremely high sorption capacities, while structural rearrangements of the network are hindered. We study the simultaneous uptake of gases and dilation of the thin films at high pressures using spectroscopic ellipsometry measurements. Ellipsometry provides the changes in both the refractive index and the film thickness, and allows for accurate quantification of sorption and swelling. In contrast, gravimetric and volumetric measurements only provide a single parameter; this does not allow an accurate correction for, for instance, the changes in buoyancy because of the extensive geometrical changes of highly swelling films. The sorption behavior of the ultrathin hybrid layers depends on the fluoroalkene group content. At low pressure, the apparent molar volume of the gases is low compared to the liquid molar volume of carbon dioxide and methane, respectively. At high gas concentrations in the polymer film, the apparent molar volume of carbon dioxide and methane exceeds that of the liquid molar volume, and approaches that of the gas phase. The high sorption capacity and reversible dilation characteristics of the presented materials provide new directions for applications including gas sensors and gas separation membranes.

Volcanic CO2 Abundance of Kilauea Plume Retrieved by Meand of AVIRIS Data

NASA Technical Reports Server (NTRS)

Spinetti, C.; Carrere, V.; Buongiorno, M. F.; Pieri, D.

2004-01-01

Absorbing the electromagnetic radiation in several regions of the solar spectrum, CO2 plays an important role in the Earth radiation budget since it produces the greenhouse effect. Many natural processes in the Earth s system add and remove carbon dioxide. Overall, measurements of atmospheric carbon dioxide at different sites around the world show an increased carbon dioxide concentration in the atmosphere. At Mauna Loa Observatory (Hawaii) the measured carbon dioxide increased from 315 to 365 ppm, in the period 1958 2000 [Keeling et al., 2001]. While at the large scale, the relationship between CO2 increase and global warming is established [IPCC, 1996], at the local scale, many studies are still needed to understand regional and local sources of carbon dioxide, such as volcanoes. The volcanic areas are particularly rich in carbon dioxide; this is due to magma degassing in the summit craters region of active volcanoes, and to the presence of fractures and active faults [Giammanco et al., 1998]. Several studies estimate a global flux of volcanic CO2 (34+/-24)10(exp 6) tons/day from effusive volcanic emissions, such as the tropospheric volcanic plume (Table 1) [McClelland et al., 1989]. Plumes are a turbulent mixture of gases, solid particles and liquid droplets, emitted continuously at high temperature from summit craters, fumarolic fields or during eruptive episodes. Inside the plume, water vapour represents 70 90% of the volcanic gases. The main gaseous components are CO2, SO2, HCl, H2, H2S, HF, CO, N2 and CH4. Other plume components are volcanic ash, aqueous and acid droplets and solid sulphur-derived particles [Sparks et al., 1997]. Volcanic gases and aerosols are evidences of volcanic activity [Spinetti et al., 2003] and they have important climatic and environmental effects [Fiocco et al., 1994]. For example, Etna volcano is one of the world s major volcanic gas sources [Allard et al., 1991]. New studies on volcanic gaseous emissions have pointed out that a variation of the gas ratio CO2/SO2 is related to eruptive episodes [Caltabiano et al., 1994]. However, measurements and monitoring of volcanic carbon dioxide are difficult and often hazardous, due to the high background presence of atmospheric CO2 and the inaccessibility of volcanic sites. Hyperspectral remote sensing is a suitable technique to overcome the difficulties of ground measurement. It permits a rapid, comprehensive view of volcanic plumes and their evolution over time, detection of all gases with absorption molecular lines within the sensor s multispectral range and, in general, measurement of all the volatile components evolving from craters. The molecular and particle plume components scatter and absorb incident solar radiation. The integral of the radiation difference composes the signal measured by the remote spectrometer. The inversion technique consists of retrieving the plume component concentrations, hence decomposing the signal into the different contributions. The accuracy of remote sensing techniques depends primarily on the sensor capability and sensitivity.

Modular chemiresistive sensor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alam, Maksudul M.; Sampathkumaran, Uma

The present invention relates to a modular chemiresistive sensor. In particular, a modular chemiresistive sensor for hypergolic fuel and oxidizer leak detection, carbon dioxide monitoring and detection of disease biomarkers. The sensor preferably has two gold or platinum electrodes mounted on a silicon substrate where the electrodes are connected to a power source and are separated by a gap of 0.5 to 4.0 .mu.M. A polymer nanowire or carbon nanotube spans the gap between the electrodes and connects the electrodes electrically. The electrodes are further connected to a circuit board having a processor and data storage, where the processor canmore » measure current and voltage values between the electrodes and compare the current and voltage values with current and voltage values stored in the data storage and assigned to particular concentrations of a pre-determined substance such as those listed above or a variety of other substances.« less

Probes Measure Gases for Environmental Research

NASA Technical Reports Server (NTRS)

2015-01-01

NASA's Orbiting Carbon Observatory-2 satellite will make the first space-based measurements of carbon dioxide in Earth's atmosphere. In support of the mission, Goddard Space Flight Center will fly air missions from Wallops Flight Facility to gather finer-grained data in areas of interest. Goddard started working with Blacksburg, Virginia-based Aeroprobe Corporation through the SBIR program in 2008 to develop sensors for such flights, and the company has since commercialized the resulting product.

Methane and Carbon Dioxide Concentrations and Fluxes in Amazon Floodplains

NASA Astrophysics Data System (ADS)

Melack, J. M.; MacIntyre, S.; Forsberg, B.; Barbosa, P.; Amaral, J. H.

2016-12-01

Field studies on the central Amazon floodplain in representative aquatic habitats (open water, flooded forests, floating macrophytes) combine measurements of methane and carbon dioxide concentrations and fluxes to the atmosphere over diel and seasonal times with deployment of meteorological sensors and high-resolution thermistors and dissolved oxygen sondes. A cavity ringdown spectrometer is used to determine gas concentrations, and floating chambers and bubble collectors are used to measure fluxes. To further understand fluxes, we measured turbulence as rate of dissipation of turbulent kinetic energy based on microstructure profiling. These results allow calculations of vertical mixing within the water column and of air-water exchanges using surface renewal models. Methane and carbon dioxide fluxes varied as a function of season, habitat and water depth. High CO2 fluxes at high water are related to high pCO2; low pCO2 levels at low water result from increased phytoplankton uptake. CO2 fluxes are highest at turbulent open water sites, and pCO2 is highest in macrophyte beds. Fluxes and pCH4 are high in macrophyte beds.

Remote fluorescence lifetime inspection of hermeticity of packaged food containers

NASA Astrophysics Data System (ADS)

Mendoza, Edgar A.; Kempen, Cornelia; Sun, Sunjian; Esterkin, Yan

2014-09-01

This paper describes recent progress towards the development of a remote "frequency-domain" fluorescence lifetime (SeePhase™) monitor used for the real time hermetic seal leak inspection of packaged food containers. A multitude of food goods, meets, vegetables, and beverages are typically packaged within an inert environment to reduce the risk of bacteria growth and increase the storage life of the food product. The SeePhase™ system uses a multi-parameter oxygen, carbon dioxide, and moisture sensitive patch that is placed within the hermetic sealed food package. Upon the presence of gases oxygen, carbon dioxide, or moisture inside the hermetic sealed food package, the sensor patch produces a fluorescence lifetime signature characteristic of a hermetic seal leak damage of the package.

Evaluation of a Prototype pCO2 Optical Sensor

NASA Astrophysics Data System (ADS)

Sanborn-Marsh, C.; Sutton, A.; Sabine, C. L.; Lawrence-Salvas, N.; Dietrich, C.

2016-12-01

Anthropogenic greenhouse gas emissions continue to rise, driving climate change and altering the ocean carbonate systems. Carbonate chemistry can be characterized by any two of the four parameters: pH, total alkalinity, dissolved inorganic carbon, and partial pressure of dissolved carbon dioxide gas (pCO2). To fully monitor these dynamic systems, researchers must deploy a more temporally and spatially comprehensive sensor network. Logistical challenges, such as the energy consumption, size, lifetime, depth range, and cost of pCO2 sensors have limited the network's reach so far. NOAA's Pacific Marine Environmental Laboratory has conducted assessment tests of a pCO2 optical sensor (optode), recently developed by Atamanchuk et al (2014). We hope to deploy this optode in the summer of 2017 on high-resolution moored profiler, along with temperature, salinity, and oxygen sensors. While most pCO2 optodes have energy consumptions of 3-10 W, this 36mm-diameter by 86mm-long instrument consumes a mere 7-80 mW. Initial testing showed that its accuracy varied within an absolute range of 2-75 μatm, depending on environmental conditions, including temperature, salinity, response time, and initial calibration. Further research independently examining the effects of each variable on the accuracy of the data will also be presented.

Microfabricated Gas Sensors Demonstrated in Fire and Emission Applications

NASA Technical Reports Server (NTRS)

Hunter, Gary W.

2003-01-01

A range of microfabricated chemical sensors are being developed to meet the needs of fire detection and emission monitoring in aerospace applications. These sensors have the advantages over traditional technology of minimal size, weight, and power consumption as well as the ability to be placed closer to where the measurements need to be made. Sensor arrays are being developed to address detection needs in environments where multiple species need to be measured. For example, the monitoring of chemical species such as carbon monoxide (CO), carbon dioxide (CO2), hydrocarbons, and other species is important in the detection of fires on airplanes and spacecraft. In contrast, different sensors are necessary for characterizing some aircraft engine designs where the monitoring of nitrogen oxides (NO(x)) and CO is of high interest. Demonstration of both fire and emission microsensor technology was achieved this year in a collaborative effort undertaken by the NASA Glenn Research Center, Case Western Reserve University, and Makel Engineering, Inc.

Reliable method for determination of the velocity of a sinker in a high-pressure falling body type viscometer

NASA Astrophysics Data System (ADS)

Dindar, Cigdem; Kiran, Erdogan

2002-10-01

We present a new sensor configuration and data reduction process to improve the accuracy and reliability of determining the terminal velocity of a falling sinker in falling body type viscometers. This procedure is based on the use of multiple linear variable differential transformer sensors and precise mapping of the sensor signal and position along with the time of fall which is then converted to distance versus fall time along the complete fall path. The method and its use in determination of high-pressure viscosity of n-pentane and carbon dioxide are described.

LED-Absorption-QEPAS Sensor for Biogas Plants

PubMed Central

Köhring, Michael; Böttger, Stefan; Willer, Ulrike; Schade, Wolfgang

2015-01-01

A new sensor for methane and carbon dioxide concentration measurements in biogas plants is presented. LEDs in the mid infrared spectral region are implemented as low cost light source. The combination of quartz-enhanced photoacoustic spectroscopy with an absorption path leads to a sensor setup suitable for the harsh application environment. The sensor system contains an electronics unit and the two gas sensors; it was designed to work as standalone device and was tested in a biogas plant for several weeks. Gas concentration dependent measurements show a precision better than 1% in a range between 40% and 60% target gas concentration for both sensors. Concentration dependent measurements with different background gases show a considerable decrease in cross sensitivity against the major components of biogas in direct comparison to common absorption based sensors. PMID:26007746

A Methane Lidar for Greenhouse Gas Measurements

NASA Technical Reports Server (NTRS)

Riris, Haris; Numata, Kenji; Wu, Stewart; Gonzalez, Brayler; Rodriguez, Michael; Fahey, Molly; Kawa, Stephan R.; Scott, Stan; Yu, Anthony; Stephen, Mark;

Evaluation of Carbon Dioxide Sensors for the Constellation Space Suit Life Support System for Surface Exploration

NASA Technical Reports Server (NTRS)

Dietrich, Daniel L.; Paul, Heather L.; Conger, Bruce C.

2009-01-01

This paper presents the findings of the trade study to evaluate carbon dioxide (CO2) sensing technologies for the Constellation (Cx) space suit life support system for surface exploration. The trade study found that nondispersive infrared absorption (NDIR) is the most appropriate high Technology Readiness Level (TRL) technology for the CO2 sensor for the Cx space suit. The maturity of the technology is high, as it is the basis for the CO2 sensor in the Extravehicular Mobility Unit (EMU). The study further determined that while there is a range of commercial sensors available, the Cx CO2 sensor should be a new design. Specifically, there are light sources (e.g., infrared light emitting diodes) and detectors (e.g., cooled detectors) that are not in typical commercial sensors due to cost. These advanced technology components offer significant advantages in performance (weight, volume, power, accuracy) to be implemented in the new sensor. The exact sensor design (light source, transmitting optics, path length, receiving optics and detector) will be specific for the Cx space suit and will be determined by the performance requirements of the Cx space suit. The paper further identifies specifications for some of the critical performance parameters as well as discussing the engineering aspects of implementing the sensor into the Portable Life Support System (PLSS). The paper then presents testing results from three CO2 sensors with respect to issues important to Extravehicular Activity (EVA) applications; stability, humidity dependence and low pressure compatibility. The three sensors include two NDIR sensors, one commercial and one custom-developed by NASA (for a different purpose), and one commercial electrochemical sensor. The results show that both NDIR sensors have excellent stability, no dependence on ambient humidity (when the ambient temperature is above the dew point) and operate in low pressure conditions and after being exposed to a full vacuum. The commercial electrochemical sensor was not suitable for the Cx space suit for surface exploration. Finally, the paper identifies a number of techniques currently under development that offer significant advantages for EVA applications. These include miniaturized, room temperature, solid electrolyte systems and advanced optical detectors.

High-Accuracy Measurements of Total Column Water Vapor From the Orbiting Carbon Observatory-2

NASA Technical Reports Server (NTRS)

Nelson, Robert R.; Crisp, David; Ott, Lesley E.; O'Dell, Christopher W.

2016-01-01

Accurate knowledge of the distribution of water vapor in Earth's atmosphere is of critical importance to both weather and climate studies. Here we report on measurements of total column water vapor (TCWV) from hyperspectral observations of near-infrared reflected sunlight over land and ocean surfaces from the Orbiting Carbon Observatory-2 (OCO-2). These measurements are an ancillary product of the retrieval algorithm used to measure atmospheric carbon dioxide concentrations, with information coming from three highly resolved spectral bands. Comparisons to high-accuracy validation data, including ground-based GPS and microwave radiometer data, demonstrate that OCO-2 TCWV measurements have maximum root-mean-square deviations of 0.9-1.3mm. Our results indicate that OCO-2 is the first space-based sensor to accurately and precisely measure the two most important greenhouse gases, water vapor and carbon dioxide, at high spatial resolution [1.3 x 2.3 km(exp. 2)] and that OCO-2 TCWV measurements may be useful in improving numerical weather predictions and reanalysis products.

Temperature-programmed technique accompanied with high-throughput methodology for rapidly searching the optimal operating temperature of MOX gas sensors.

PubMed

Zhang, Guozhu; Xie, Changsheng; Zhang, Shunping; Zhao, Jianwei; Lei, Tao; Zeng, Dawen

2014-09-08

A combinatorial high-throughput temperature-programmed method to obtain the optimal operating temperature (OOT) of gas sensor materials is demonstrated here for the first time. A material library consisting of SnO2, ZnO, WO3, and In2O3 sensor films was fabricated by screen printing. Temperature-dependent conductivity curves were obtained by scanning this gas sensor library from 300 to 700 K in different atmospheres (dry air, formaldehyde, carbon monoxide, nitrogen dioxide, toluene and ammonia), giving the OOT of each sensor formulation as a function of the carrier and analyte gases. A comparative study of the temperature-programmed method and a conventional method showed good agreement in measured OOT.

Field Micrometeorological Measurements, Process-Level Studies and Modeling of Methane and Carbon Dioxide Fluxes in a Boreal Wetland Ecosystem

NASA Technical Reports Server (NTRS)

Verma, S. B.; Arkebauer, T. J.; Ullman, F. G.; Valentine, D. W.; Parton, W. J.; Schimel, D. S.

1998-01-01

The main instrumentation platform consisted of eddy correlation sensors mounted on a scaffold tower at a height of 4.2 m above the peat surface. The sensors were attached to a boom assembly which could be rotated into the prevailing winds. The boom assembly was mounted on a movable sled which, when extended, allowed sensors to be up to 2 m away from the scaffolding structure to minimize flow distortion. When retracted, the sensors could easily be installed, serviced or rotated. An electronic level with linear actuators allowed the sensors to be remotely levelled once the sled was extended. Two instrument arrays were installed. A primary (fast-response) array consisted of a three-dimensional sonic anemometer, a methane sensor (tunable diode laser spectrometer), a carbon dioxide/water vapor sensor, a fine wire thermocouple and a backup one-dimensional sonic anemometer. The secondary array consisted of a one-dimensional sonic anemometer, a fine wire thermocouple and a Krypton hygrometer. Descriptions of these sensors may be found in other reports (e.g., Verma; Suyker and Verma). Slow-response sensors provided supporting measurements including mean air temperature and humidity, mean horizontal windspeed and direction, incoming and reflected solar radiation, net radiation, incoming and reflected photosynthetically active radiation (PAR), soil heat flux, peat temperature, water-table elevation and precipitation. A data acquisition system (consisting of an IBM compatible microcomputer, amplifiers and a 16 bit analog-to-digital converter), housed in a small trailer, was used to record the fast response signals. These signals were low-pass filtered (using 8-pole Butterworth active filters with a 12.5 Hz cutoff frequency) and sampled at 25 Hz. Slow-response signals were sampled every 5 s using a network of CR21X (Campbell Scientific, Inc., Logan Utah) data loggers installed in the fen. All signals were averaged over 30-minute periods (runs).

Flexible Graphene-Based Wearable Gas and Chemical Sensors.

PubMed

Singh, Eric; Meyyappan, M; Nalwa, Hari Singh

2017-10-11

Wearable electronics is expected to be one of the most active research areas in the next decade; therefore, nanomaterials possessing high carrier mobility, optical transparency, mechanical robustness and flexibility, lightweight, and environmental stability will be in immense demand. Graphene is one of the nanomaterials that fulfill all these requirements, along with other inherently unique properties and convenience to fabricate into different morphological nanostructures, from atomically thin single layers to nanoribbons. Graphene-based materials have also been investigated in sensor technologies, from chemical sensing to detection of cancer biomarkers. The progress of graphene-based flexible gas and chemical sensors in terms of material preparation, sensor fabrication, and their performance are reviewed here. The article provides a brief introduction to graphene-based materials and their potential applications in flexible and stretchable wearable electronic devices. The role of graphene in fabricating flexible gas sensors for the detection of various hazardous gases, including nitrogen dioxide (NO 2 ), ammonia (NH 3 ), hydrogen (H 2 ), hydrogen sulfide (H 2 S), carbon dioxide (CO 2 ), sulfur dioxide (SO 2 ), and humidity in wearable technology, is discussed. In addition, applications of graphene-based materials are also summarized in detecting toxic heavy metal ions (Cd, Hg, Pb, Cr, Fe, Ni, Co, Cu, Ag), and volatile organic compounds (VOCs) including nitrobenzene, toluene, acetone, formaldehyde, amines, phenols, bisphenol A (BPA), explosives, chemical warfare agents, and environmental pollutants. The sensitivity, selectivity and strategies for excluding interferents are also discussed for graphene-based gas and chemical sensors. The challenges for developing future generation of flexible and stretchable sensors for wearable technology that would be usable for the Internet of Things (IoT) are also highlighted.

Electrocatalysts for carbon dioxide conversion

DOEpatents

Masel, Richard I; Salehi-Khojin, Amin

2015-04-21

Electrocatalysts for carbon dioxide conversion include at least one catalytically active element with a particle size above 0.6 nm. The electrocatalysts can also include a Helper Catalyst. The catalysts can be used to increase the rate, modify the selectivity or lower the overpotential of electrochemical conversion of CO.sub.2. Chemical processes and devices using the catalysts also include processes to produce CO, HCO.sup.-, H.sub.2CO, (HCO.sub.2).sup.-, H.sub.2CO.sub.2, CH.sub.3OH, CH.sub.4, C.sub.2H.sub.4, CH.sub.3CH.sub.2OH, CH.sub.3COO.sup.-, CH.sub.3COOH, C.sub.2H.sub.6, (COOH).sub.2, or (COO.sup.-).sub.2, and a specific device, namely, a CO.sub.2 sensor.

Active Control of pH in the Bioculture System Through Carbon Dioxide Control

NASA Technical Reports Server (NTRS)

Monhollon, Luke; Pletcher, David; Hauss, Jessica

2016-01-01

For successful cell research, the growth culture environment must be tightly controlled. Deviance from the optimal conditions will mask the desired variable being analyzed or lead to inconstancies in the results. In standard laboratories, technology and procedures are readily available for the reliable control of variables such as temperature, pH, nutrient loading, and dissolved gases. Due to the nature of spaceflight, and the inherent constraints to engineering designs, these same elements become a challenge to maintain at stable values by both automated and manual approaches. Launch mass, volume, and power usage create significant constraints to cell culture systems; nonetheless, innovative solutions for active environmental controls are available. The acidity of the growth media cannot be measured through standard probes due to the degradation of electrodes and reliance on indicators for chromatography. Alternatively, carbon dioxide sensors are capable of monitoring the pH by leveraging the relationship between the partial pressure of carbon dioxide and carbonic acid in solution across a membrane. In microgravity cell growth systems, the gas delivery system can be used to actively maintain the media at the proper acidity by maintaining a suitable gas mixture around permeable tubing. Through this method, launch mass and volume are significantly reduced through the efficient use of the limited gas supply in orbit.

Development and Application of Microfabricated Chemical Gas Sensors For Aerospace Applications

NASA Technical Reports Server (NTRS)

Hunter, G. W.; Neudeck, P. G.; Fralick, G.; Thomas, V.; Liu, C. C.; Wu, Q. H.; Sawayda, M. S.; Jin, A.; Hammond, J.; Makel, D.;

Development of Microfabricated Chemical Gas Sensors and Sensor Arrays for Aerospace Applications

NASA Technical Reports Server (NTRS)

Hunter, G. W.; Neudeck, P. G.; Fralick, G.; Thomas, V.; Liu, C. C.; Wu, W. H.; Ward, B.; Makel, D.

2002-01-01

Aerospace applications require the development of chemical sensors with capabilities beyond those of commercially available sensors. In particular, factors such as minimal sensor size, weight, and power consumption are particularly important. Development areas which have potential aerospace applications include launch vehicle leak detection, engine health monitoring, fire detection, and environmental monitoring. Sensor development for these applications is based on progress in three types of technology: 1) Micromachining and microfabrication (Microsystem) technology to fabricate miniaturized sensors. 2) The use of nanocrystalline materials to develop sensors with improved stability combined with higher sensitivity. 3) The development of high temperature semiconductors, especially silicon carbide. However, due to issues of selectivity and cross-sensitivity, individual sensors are limited in the amount of information that they can provide in environments that contain multiple chemical species. Thus, sensor arrays are being developed to address detection needs in such multi-species environments. This paper discusses the needs of space applications as well as the point-contact sensor technology and sensor arrays being developed to address these needs. Sensors to measure hydrogen, hydrocarbons, hydrazine, nitrogen oxides (NO,), carbon monoxide, oxygen, and carbon dioxide are being developed as well as arrays for leak, fire, and emissions detection. Demonstrations of the technology will also be discussed. It is concluded that microfabricated sensor technology has significant potential for use in a range of aerospace applications.

Time-resolved fluorescence spectroscopy for chemical sensors

NASA Astrophysics Data System (ADS)

Draxler, Sonja; Lippitsch, Max E.

1996-07-01

A family of sensors is presented with fluorescence decay-time measurements used as the sensing technique. The concept is to take a single fluorophore with a suitably long fluorescence decay time as the basic building block for numerous different sensors. Analyte recognition can be performed by different functional groups that are necessary for selective interaction with the analyte. To achieve this, the principle of excited-state electron transfer is applied with pyrene as the fluorophore. Therefore the same instrumentation based on a small, ambient air-nitrogen laser and solid-state electronics can be used to measure different analytes, for example, oxygen, pH, carbon dioxide, potassium, ammonium, lead, cadmium, zinc, and phosphate.

Optimized heat exchange in a CO2 de-sublimation process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baxter, Larry; Terrien, Paul; Tessier, Pascal

The present invention is a process for removing carbon dioxide from a compressed gas stream including cooling the compressed gas in a first heat exchanger, introducing the cooled gas into a de-sublimating heat exchanger, thereby producing a first solid carbon dioxide stream and a first carbon dioxide poor gas stream, expanding the carbon dioxide poor gas stream, thereby producing a second solid carbon dioxide stream and a second carbon dioxide poor gas stream, combining the first solid carbon dioxide stream and the second solid carbon dioxide stream, thereby producing a combined solid carbon dioxide stream, and indirectly exchanging heat betweenmore » the combined solid carbon dioxide stream and the compressed gas in the first heat exchanger.« less

Combustion Products Monitor: Trade Study Testing

NASA Technical Reports Server (NTRS)

Wallace, William T.; Trowbridge, John B.

2011-01-01

Current combustion products monitoring on the International Space Station (ISS) uses a handheld device (Compound Specific Analyzer-Combustion Products, CSA-CP) containing electrochemical sensors used to measure the concentration of carbon monoxide (CO), hydrogen chloride (HCl), hydrogen cyanide (HCN), and oxygen (O2). The CO sensor in this device accounts for a well-known cross-sensitivity with hydrogen (H2), which is important, as ISS air can contain up to 100 ppm H2. Unfortunately, this current device is being discontinued, and due to space constraints, the new model cannot accommodate the size of the current CO sensor. Therefore, a trade study was conducted in order to determine which CO sensors on the market were available with compensation for H2, and which instruments used these sensors, while also measuring HCN, O2, and carbon dioxide (CO2). The addition of CO2 to the device is helpful, as current monitoring of this gas requires a second hand-held monitor. By providing a device that will monitor both combustion products and CO2, volume and up-mass can be reduced as these monitors are delivered to ISS.

Expanding the Capabilities of the JPL Electronic Nose for an International Space Station Technology Demonstration

NASA Technical Reports Server (NTRS)

Ryan, Margaret A.; Shevade, A. V.; Taylor, C. J.; Homer, M. L.; Jewell, A. D.; Kisor, A.; Manatt, K. S .; Yen, S. P. S.; Blanco, M.; Goddard, W. A., III

2006-01-01

An array-based sensing system based on polymer/carbon composite conductometric sensors is under development at JPL for use as an environmental monitor in the International Space Station. Sulfur dioxide has been added to the analyte set for this phase of development. Using molecular modeling techniques, the interaction energy between SO2 and polymer functional groups has been calculated, and polymers selected as potential SO2 sensors. Experiment has validated the model and two selected polymers have been shown to be promising materials for SO2 detection.

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

DOEpatents

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

2013-01-29

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

Buoy monitors ocean acidification

NASA Astrophysics Data System (ADS)

Zielinski, Sarah

2007-06-01

A new Gulf of Alaska buoy installed on 7 June is the first to provide data that will help scientists study ocean acidification caused by the absorption of atmospheric carbon dioxide. Sensors attached to the buoy are measuring key climate indicators in the atmosphere and ocean, including surface acidity and the air-sea exchange of carbon dioxide. The buoy was installed in collaboration with the Line P program, which has provided decades of continuous measurements from a series of oceanographic stations along line P which extends from the mouth of the Juan de Fuca Strait south of Vancouver Island to Pacific Ocean Station Papa, where the new buoy was installed.The buoy is part of a project conducted by scientists from NOAAs Pacific Marine Environmental Laboratory; the University of Washington, Seattle; Fisheries and Oceans Canada; and the Institute of Ocean Sciences in Sydney, British Columbia.

2-Micron Triple-Pulse Integrated Path Differential Absorption Lidar Development for Simultaneous Airborne Column Measurements of Carbon Dioxide and Water Vapor in the Atmosphere

NASA Technical Reports Server (NTRS)

Singh, Upendra N.; Petros, Mulugeta; Refaat, Tamer F.; Yu, Jirong

2016-01-01

For more than 15 years, NASA Langley Research Center (LaRC) has contributed in developing several 2-micron carbon dioxide active remote sensors using the DIAL technique. Currently, an airborne 2-micron triple-pulse integrated path differential absorption (IPDA) lidar is under development at NASA LaRC. This paper focuses on the advancement of the 2-micron triple-pulse IPDA lidar development. Updates on the state-of-the-art triple-pulse laser transmitter will be presented including the status of wavelength control, packaging and lidar integration. In addition, receiver development updates will also be presented, including telescope integration, detection systems and data acquisition electronics. Future plan for IPDA lidar system for ground integration, testing and flight validation will be presented.

Carbon Nanotube Based Chemical Sensors for Space and Terrestrial Applications

NASA Technical Reports Server (NTRS)

Li, Jing; Lu, Yijiang

2009-01-01

A nanosensor technology has been developed using nanostructures, such as single walled carbon nanotubes (SWNTs), on a pair of interdigitated electrodes (IDE) processed with a silicon-based microfabrication and micromachining technique. The IDE fingers were fabricated using photolithography and thin film metallization techniques. Both in-situ growth of nanostructure materials and casting of the nanostructure dispersions were used to make chemical sensing devices. These sensors have been exposed to nitrogen dioxide, acetone, benzene, nitrotoluene, chlorine, and ammonia in the concentration range of ppm to ppb at room temperature. The electronic molecular sensing of carbon nanotubes in our sensor platform can be understood by intra- and inter-tube electron modulation in terms of charge transfer mechanisms. As a result of the charge transfer, the conductance of p-type or hole-richer SWNTs in air will change. Due to the large surface area, low surface energy barrier and high thermal and mechanical stability, nanostructured chemical sensors potentially can offer higher sensitivity, lower power consumption and better robustness than the state-of-the-art systems, which make them more attractive for defense and space applications. Combined with MEMS technology, light weight and compact size sensors can be made in wafer scale with low cost. Additionally, a wireless capability of such a sensor chip can be used for networked mobile and fixed-site detection and warning systems for military bases, facilities and battlefield areas.

Dynamic model inversion techniques for breath-by-breath measurement of carbon dioxide from low bandwidth sensors.

PubMed

Sivaramakrishnan, Shyam; Rajamani, Rajesh; Johnson, Bruce D

2009-01-01

Respiratory CO(2) measurement (capnography) is an important diagnosis tool that lacks inexpensive and wearable sensors. This paper develops techniques to enable use of inexpensive but slow CO(2) sensors for breath-by-breath tracking of CO(2) concentration. This is achieved by mathematically modeling the dynamic response and using model-inversion techniques to predict input CO(2) concentration from the slow-varying output. Experiments are designed to identify model-dynamics and extract relevant model-parameters for a solidstate room monitoring CO(2) sensor. A second-order model that accounts for flow through the sensor's filter and casing is found to be accurate in describing the sensor's slow response. The resulting estimate is compared with a standard-of-care respiratory CO(2) analyzer and shown to effectively track variation in breath-by-breath CO(2) concentration. This methodology is potentially useful for measuring fast-varying inputs to any slow sensor.

Gold-on-Polymer-Based Sensing Films for Detection of Organic and Inorganic Analytes in the Air

NASA Technical Reports Server (NTRS)

Manatt, Kenneth; Homer, Margie; Ryan, Margaret; Kisor, Adam; Shevade, Abhijit; Jewell, April; Zhou, Hanying

2008-01-01

A document discusses gold-on-polymer as one of the novel sensor types developed for part of the sensor development task. Standard polymer-carbon composite sensors used in the JPL Electronic Nose (ENose) have been modified by evaporating 15 nm of metallic gold on the surface. These sensors have been shown to respond to alcohols, aromatics, ammonia, sulfur dioxide, and elemental mercury in the parts-per-million and parts-per-billion concentration ranges in humidified air. The results have shown good sensitivity of these films operating under mild conditions (operating temperatures 23-28 C and regeneration temperature up to 40 C). This unique sensor combines the diversity of polymer sensors for chemical sensing with their response to a wide variety of analytes with the specificity of a gold sensor that shows strong reaction/binding with selected analyte types, such as mercury or sulfur.

Improving indoor air quality through the use of continual multipoint monitoring of carbon dioxide and dew point.

PubMed

Bearg, D W

1998-09-01

This article summarizes an approach for improving the indoor air quality (IAQ) in a building by providing feedback on the performance of the ventilation system. The delivery of adequate quantities of ventilation to all building occupants is necessary for the achievement of good IAQ. Feedback on the performance includes information on the adequacy of ventilation provided, the effectiveness of the distribution of this air, the adequacy of the duration of operation of the ventilation system, and the identification of leakage into the return plenum, either of outdoor or supply air. Keeping track of ventilation system performance is important not only in terms of maintaining good IAQ, but also making sure that this system continues to perform as intended after changes in building use. Information on the performance of the ventilation system is achieved by means of an automated sampling system that draws air from multiple locations and delivers it to both a carbon dioxide monitor and dew point sensor. The use of single shared sensors facilitates calibration checks as well as helps to guarantee data integrity. This approach to monitoring a building's ventilation system offers the possibility of achieving sustainable performance of this important aspect of good IAQ.

Bio-Optical Measurements at Ocean Boundaries in Support of SIMBIOS. Chapter 7

NASA Technical Reports Server (NTRS)

Chavez, Francisco P.; Strutton, Peter G.; Schlining, Brian M.

2001-01-01

The equatorial Pacific is a major component of global biogeochemical cycles, due to upwelling that occurs from the coast of South America to beyond 180 deg. This upwelling has significant implications for global CO2 fluxes, as well as primary and secondary production. In addition, this region of the world's oceans represents a large oceanic province over which validation data for Sea-Viewing Wide Field-of-view Sensor (SeaWiFS) are necessary. This project consists of a mooring program and supporting cruise-based measurements aimed at quantifying the spectrum of biological and chemical variability in the equatorial Pacific and obtaining validation data for SeaWiFS. The project has the following general objectives: (1) to understand the relationships between physical forcing, primary production, nutrient supply and the exchange of carbon dioxide between ocean and atmosphere in the equatorial Pacific; (2) to describe the biological and chemical responses to climate and ocean variability; (3) to describe the spatial, seasonal and inter-annual variability in near surface plant pigments, primary production, carbon dioxide and nutrient distributions; and (4) to obtain near real-time bio-optical measurements for validation of SeaWiFS and subsequent ocean color sensors.

Gas Exchange of Algae

PubMed Central

Ammann, Elizabeth C. B.; Lynch, Victoria H.

1967-01-01

The oxygen production of a photosynthetic gas exchanger containing Chlorella pyrenoidosa (1% packed cell volume) was measured when various concentrations of carbon dioxide were present within the culture unit. The internal carbon dioxide concentrations were obtained by manipulating the entrance gas concentration and the flow rate. Carbon dioxide percentages were monitored by means of electrodes placed directly in the nutrient medium. The concentration of carbon dioxide in the nutrient medium which produced maximal photosynthesis was in the range of 1.5 to 2.5% by volume. Results were unaffected by either the level of carbon dioxide in the entrance gas or the rate of gas flow. Entrance gases containing 2% carbon dioxide flowing at 320 ml/min, 3% carbon dioxide at 135 ml/min, and 4% carbon dioxide at 55 ml/min yielded optimal carbon dioxide concentrations in the particular unit studied. By using carbon dioxide electrodes implanted directly in the gas exchanger to optimize the carbon dioxide concentration throughout the culture medium, it should be possible to design more efficient large-scale units. PMID:4382391

Low-cost Photoacoustic-based Measurement System for Carbon Dioxide Fluxes with the Potential for large-scale Monitoring

NASA Astrophysics Data System (ADS)

Scholz, L. T.; Bierer, B.; Ortiz Perez, A.; Woellenstein, J.; Sachs, T.; Palzer, S.

2016-12-01

The determination of carbon dioxide (CO2) fluxes between ecosystems and the atmosphere is crucial for understanding ecological processes on regional and global scales. High quality data sets with full uncertainty estimates are needed to evaluate model simulations. However, current flux monitoring techniques are unsuitable to provide reliable data of a large area at both a detailed level and an appropriate resolution, at best in combination with a high sampling rate. Currently used sensing technologies, such as non-dispersive infrared (NDIR) gas analyzers, cannot be deployed in large numbers to provide high spatial resolution due to their costs and complex maintenance requirements. Here, we propose a novel CO2 measurement system, whose gas sensing unit is made up of low-cost, low-power consuming components only, such as an IR-LED and a photoacoustic detector. The sensor offers a resolution of < 50 ppm in the interesting concentration range up to 5000 ppm and an almost linear and fast sensor response of just a few seconds. Since the sensor can be applied in-situ without special precautions, it allows for environmental monitoring in a non-invasive way. Its low energy consumption enables long-term measurements. The low overall costs favor the manufacturing in large quantities. This allows the operation of multiple sensors at a reasonable price and thus provides concentration measurements at any desired spatial coverage and at high temporal resolution. With appropriate 3D configuration of the units, vertical and horizontal fluxes can be determined. By applying a closely meshed wireless sensor network, inhomogeneities as well as CO2 sources and sinks in the lower atmosphere can be monitored. In combination with sensors for temperature, pressure and humidity, our sensor paves the way towards the reliable and extensive monitoring of ecosystem-atmosphere exchange rates. The technique can also be easily adapted to other relevant greenhouse gases.

Improved selectivity towards NO₂ of phthalocyanine-based chemosensors by means of original indigo/nanocarbons hybrid material.

PubMed

Brunet, J; Pauly, A; Dubois, M; Rodriguez-Mendez, M L; Ndiaye, A L; Varenne, C; Guérin, K

2014-09-01

A new and original gas sensor-system dedicated to the selective monitoring of nitrogen dioxide in air and in the presence of ozone, has been successfully achieved. Because of its high sensitivity and its partial selectivity towards oxidizing pollutants (nitrogen dioxide and ozone), copper phthalocyanine-based chemoresistors are relevant. The selectivity towards nitrogen dioxide results from the implementation of a high efficient and selective ozone filter upstream the sensing device. Thus, a powdered indigo/nanocarbons hybrid material has been developed and investigated for such an application. If nanocarbonaceous material acts as a highly permeable matrix with a high specific surface area, immobilized indigo nanoparticles are involved into an ozonolysis reaction with ozone leading to the selective removal of this analytes from air sample. The filtering yields towards each gas have been experimentally quantified and establish the complete removal of ozone while having the concentration of nitrogen dioxide unchanged. Long-term gas exposures reveal the higher durability of hybrid material as compared to nanocarbons and indigo separately. Synthesis, characterizations by many complementary techniques and tests of hybrid filters are detailed. Results on sensor-system including CuPc-based chemoresistors and indigo/carbon nanotubes hybrid material as in-line filter are illustrated. Sensing performances will be especially discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

Measurement of carbon capture efficiency and stored carbon leakage

DOEpatents

Keeling, Ralph F.; Dubey, Manvendra K.

2013-01-29

Data representative of a measured carbon dioxide (CO.sub.2) concentration and of a measured oxygen (O.sub.2) concentration at a measurement location can be used to determine whether the measured carbon dioxide concentration at the measurement location is elevated relative to a baseline carbon dioxide concentration due to escape of carbon dioxide from a source associated with a carbon capture and storage process. Optionally, the data can be used to quantify a carbon dioxide concentration increase at the first location that is attributable to escape of carbon dioxide from the source and to calculate a rate of escape of carbon dioxide from the source by executing a model of gas-phase transport using at least the first carbon dioxide concentration increase. Related systems, methods, and articles of manufacture are also described.

Film Sensor Device Fabricated by a Piezoelectric Poly(L-lactic acid) Film

NASA Astrophysics Data System (ADS)

Ando, Masamichi; Kawamura, Hideki; Kageyama, Keisuke; Tajitsu, Yoshiro

2012-09-01

Synthetic piezoelectric polymer films produced from petroleum feedstock have long been used as thin-film sensors and actuators. However, the fossil fuel requirements for synthetic polymer production and carbon dioxide emission from its combustion have raised concern about the environmental impact of its continued use. Eco-friendly biomass polymers, such as poly(L-lactic acid) (PLLA), are made from plant-based (vegetable starch) plastics and, thus, have a much smaller carbon footprint. Additionally, PLLA does not exhibit pyroelectricity or unnecessary poling. This suggests the usefulness of PLLA films for the human-machine interface (HMI). As an example of a new HMI, we have produced a TV remote control using a PLLA film. The intuitive operation provided by this PLLA device suggests that it is useful for the elderly or handicapped.

Carbon Dioxide Embolism during Laparoscopic Surgery

PubMed Central

Park, Eun Young; Kwon, Ja-Young

2012-01-01

Clinically significant carbon dioxide embolism is a rare but potentially fatal complication of anesthesia administered during laparoscopic surgery. Its most common cause is inadvertent injection of carbon dioxide into a large vein, artery or solid organ. This error usually occurs during or shortly after insufflation of carbon dioxide into the body cavity, but may result from direct intravascular insufflation of carbon dioxide during surgery. Clinical presentation of carbon dioxide embolism ranges from asymptomatic to neurologic injury, cardiovascular collapse or even death, which is dependent on the rate and volume of carbon dioxide entrapment and the patient's condition. We reviewed extensive literature regarding carbon dioxide embolism in detail and set out to describe the complication from background to treatment. We hope that the present work will improve our understanding of carbon dioxide embolism during laparoscopic surgery. PMID:22476987

Carbon dioxide conversion over carbon-based nanocatalysts.

PubMed

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

2013-07-01

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

Optimizing the withdrawal speed using dip coating for optical sensor

NASA Astrophysics Data System (ADS)

Samat, S. F. A.; Sarah, M. S. P.; Idros, M. Faizol Md; Rusop, M.

2018-05-01

The processing route of sol-gel has been used for many productions of thin film using metal oxide such as titanium dioxide, zinc oxide, carbon dioxide and so on. For this research the thin film phase was studied has high transmittance using dip coating technique with different withdrawal speed for optical sensing. The result obtained from optical transmittance spectra that transmits at 30nm and bend at 350nm to 800nm was in the visible light wavelength range. From the data, the withdrawal speed was low at 5s and 10s could give the highest transmittance which were 90.41% and 87.91% respectively.

Research Progress in Carbon Dioxide Storage and Enhanced Oil Recovery

NASA Astrophysics Data System (ADS)

Wang, Keliang; Wang, Gang; Lu, Chunjing

2018-02-01

With the rapid development of global economy, human beings have become highly dependent upon fossil fuel such as coal and petroleum. Much fossil fuel is consumed in industrial production and human life. As a result, carbon dioxide emissions have been increasing, and the greenhouse effects thereby generated are posing serious threats to environment of the earth. These years, increasing average global temperature, frequent extreme weather events and climatic changes cause material disasters to the world. After scientists’ long-term research, ample evidences have proven that emissions of greenhouse gas like carbon dioxide have brought about tremendous changes to global climate. To really reduce carbon dioxide emissions, governments of different countries and international organizations have invested much money and human resources in performing research related to carbon dioxide emissions. Manual underground carbon dioxide storage and carbon dioxide-enhanced oil recovery are schemes with great potential and prospect for reducing carbon dioxide emissions. Compared with other schemes for reducing carbon dioxide emissions, aforementioned two schemes exhibit high storage capacity and yield considerable economic benefits, so they have become research focuses for reducing carbon dioxide emissions. This paper introduces the research progress in underground carbon dioxide storage and enhanced oil recovery, pointing out the significance and necessity of carbon dioxide-driven enhanced oil recovery.

[Plant responses to elevated atmospheric carbon dioxide and transmission to other trophic levels]. Progress report, May 1991, DOE Grant DE-FG09-84ER60255

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lincoln, D.E.

1991-05-01

Experiments were performed to determine the effects of carbon dioxide on plants and on the insects feeding on these plants. Current progress is reported for the following experiments: Response of a Specialist-Feeding Insect Herbivore to Carbon Dioxide Induced Changes in Its Hostplant; Growth and Reproduction of Grasshoppers Feeding on a C{sub 4} Grass Under Elevated Carbon Dioxide; Elevated Carbon Dioxide and Temperature Effects on Growth and Defense of Big Sagebrush; Sagebrush and Grasshopper Responses to Atmospheric Carbon Dioxide Concentration; Biomass Allocation Patterns of Defoliated Sagebrush Grown Under Two Levels of Carbon Dioxide; and Sagebrush Carbon Allocation Patterns and Grasshopper Nutrition:more » The Influence of Carbon Dioxide Enrichment and Soil Mineral Limitation.« less

Tracking bio-hydrogen-mediated production of commodity chemicals from carbon dioxide and renewable electricity.

PubMed

Puig, Sebastià; Ganigué, Ramon; Batlle-Vilanova, Pau; Balaguer, M Dolors; Bañeras, Lluís; Colprim, Jesús

2017-03-01

This study reveals that reduction of carbon dioxide (CO 2 ) to commodity chemicals can be functionally compartmentalized in bioelectrochemical systems. In the present example, a syntrophic consortium composed by H 2 -producers (Rhodobacter sp.) in the biofilm is combined with carboxidotrophic Clostridium species, mainly found in the bulk liquid. The performance of these H 2 -mediated electricity-driven systems could be tracked by the activity of a biological H 2 sensory protein identified at cathode potentials between -0.2V and -0.3V vs SHE. This seems to point out that such signal is not strain specific, but could be detected in any organism containing hydrogenases. Thus, the findings of this work open the door to the development of a biosensor application or soft sensors for monitoring such systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Carbon Dioxide, Hydrographic, and Chemical Data Obtained During the R/V Thomas G. Thompson Cruise in the Pacific Ocean

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sabine, C.L.; Key, R.M.; Hall, M.

1999-08-01

This data documentation discusses the procedures and methods used to measure total carbon dioxide (TCO2), total alkalinity (TALK), and radiocarbon (delta 14C), at hydrographic stations, as well as the underway partial pressure of CO2 (pCO2) during the R/V Thomas G. Thompson oceanographic cruise in the Pacific Ocean (Section P10). Conducted as part of the World Ocean Circulation Experiment (WOCE), the cruise began in Suva, Fiji, on October 5, 1993, and ended in Yokohama, Japan, on November 10, 1993. Measurements made along WOCE Section P10 included pressure, temperature, salinity [measured by conductivity temperature, and depth sensor (CTD)], bottle salinity, bottle oxygen,more » phosphate, nitrate, silicate, chlorofluorocarbons (CFC-11, CFC-12), TCO2, TALK, delta 14C, and underway pCO2.« less

21 CFR 868.1400 - Carbon dioxide gas analyzer.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon dioxide...

21 CFR 868.1400 - Carbon dioxide gas analyzer.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon dioxide...

46 CFR 108.627 - Carbon dioxide alarm.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide alarm. 108.627 Section 108.627 Shipping... EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide alarm. Each carbon dioxide alarm must be identified by marking: “WHEN ALARM SOUNDS VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED” next to...

46 CFR 169.732 - Carbon dioxide alarm.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide alarm. 169.732 Section 169.732 Shipping... Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide alarm. Each carbon dioxide alarm must be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.” ...

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

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Carbon dioxide alarm-T/ALL. 35.40-7 Section 35.40-7... Requirements-TB/ALL. § 35.40-7 Carbon dioxide alarm—T/ALL. Adjacent to all carbon dioxide fire extinguishing... AT ONCE. CARBON DIOXIDE BEING RELEASED.” ...

21 CFR 868.1400 - Carbon dioxide gas analyzer.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon dioxide...

46 CFR 169.732 - Carbon dioxide alarm.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Carbon dioxide alarm. 169.732 Section 169.732 Shipping... Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide alarm. Each carbon dioxide alarm must be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.” ...

21 CFR 868.1400 - Carbon dioxide gas analyzer.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon dioxide...

21 CFR 862.1160 - Bicarbonate/carbon dioxide test system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Bicarbonate/carbon dioxide test system. 862.1160... Systems § 862.1160 Bicarbonate/carbon dioxide test system. (a) Identification. A bicarbonate/carbon dioxide test system is a device intended to measure bicarbonate/carbon dioxide in plasma, serum, and whole...

Carbon dioxide production during cardiopulmonary bypass: pathophysiology, measure and clinical relevance.

PubMed

Ranucci, Marco; Carboni, Giovanni; Cotza, Mauro; de Somer, Filip

2017-01-01

Carbon dioxide production during cardiopulmonary bypass derives from both the aerobic metabolism and the buffering of lactic acid produced by tissues under anaerobic conditions. Therefore, carbon dioxide removal monitoring is an important measure of the adequacy of perfusion and oxygen delivery. However, routine monitoring of carbon dioxide removal is not widely applied. The present article reviews the main physiological and pathophysiological sources of carbon dioxide, the available techniques to assess carbon dioxide production and removal and the clinically relevant applications of carbon dioxide-related variables as markers of the adequacy of perfusion during cardiopulmonary bypass.

46 CFR 35.40-8 - Carbon dioxide warning signs-T/ALL.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Carbon dioxide warning signs-T/ALL. 35.40-8 Section 35... Marking Requirements-TB/ALL § 35.40-8 Carbon dioxide warning signs—T/ALL. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space into which carbon...

46 CFR 35.40-8 - Carbon dioxide warning signs-T/ALL.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Carbon dioxide warning signs-T/ALL. 35.40-8 Section 35... Marking Requirements-TB/ALL § 35.40-8 Carbon dioxide warning signs—T/ALL. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space into which carbon...

Real-Time Monitoring of Critical Care Analytes in the Bloodstream with Chemical Sensors: Progress and Challenges.

PubMed

Frost, Megan C; Meyerhoff, Mark E

2015-01-01

We review approaches and challenges in developing chemical sensor-based methods to accurately and continuously monitor levels of key analytes in blood related directly to the status of critically ill hospitalized patients. Electrochemical and optical sensor-based technologies have been pursued to measure important critical care species in blood [i.e., oxygen, carbon dioxide, pH, electrolytes (K(+), Na(+), Cl(-), etc.), glucose, and lactate] in real-time or near real-time. The two main configurations examined to date for achieving this goal have been intravascular catheter sensors and patient attached ex vivo sensors with intermittent blood sampling via an attached indwelling catheter. We discuss the status of these configurations and the main issues affecting the accuracy of the measurements, including cell adhesion and thrombus formation on the surface of the sensors, sensor drift, sensor selectivity, etc. Recent approaches to mitigate these nagging performance issues that have prevented these technologies from clinical use are also discussed.

46 CFR 78.47-9 - Carbon dioxide alarm.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 3 2010-10-01 2010-10-01 false Carbon dioxide alarm. 78.47-9 Section 78.47-9 Shipping... and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.” (b) [Reserved] ...

46 CFR 196.37-9 - Carbon dioxide alarm.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide alarm. 196.37-9 Section 196.37-9 Shipping... Markings for Fire and Emergency Equipment, etc. § 196.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING...

46 CFR 76.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 3 2010-10-01 2010-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as... than 300 pounds of carbon dioxide, may have the cylinders located within the space protected. If the...

46 CFR 97.37-9 - Carbon dioxide alarm.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9 Shipping... Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING...

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

Code of Federal Regulations, 2010 CFR

2010-10-01

... hazardous liquids or carbon dioxide. 195.4 Section 195.4 Transportation Other Regulations Relating to... necessary for transportation of hazardous liquids or carbon dioxide. No person may transport any hazardous liquid or carbon dioxide unless the hazardous liquid or carbon dioxide is chemically compatible with both...

46 CFR 196.37-9 - Carbon dioxide alarm.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Carbon dioxide alarm. 196.37-9 Section 196.37-9 Shipping... Markings for Fire and Emergency Equipment, etc. § 196.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING...

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

Code of Federal Regulations, 2014 CFR

2014-10-01

... hazardous liquids or carbon dioxide. 195.4 Section 195.4 Transportation Other Regulations Relating to... necessary for transportation of hazardous liquids or carbon dioxide. No person may transport any hazardous liquid or carbon dioxide unless the hazardous liquid or carbon dioxide is chemically compatible with both...

NASA Carbon Sleuth Begins Year Two

NASA Image and Video Library

2015-10-29

Global average carbon dioxide concentrations as seen by NASA’s Orbiting Carbon Observatory-2 mission, June 1-15, 2015. OCO-2 measures carbon dioxide from the top of Earth's atmosphere to its surface. Higher carbon dioxide concentrations are in red, with lower concentrations in yellows and greens. Scientists poring over data from OCO-2 mission are seeing patterns emerge as they seek answers to questions about atmospheric carbon dioxide. Among the most striking features visible in the first year of OCO-2 data is the increase in carbon dioxide in the northern hemisphere during winter, when trees are not removing carbon dioxide, followed by its decrease in spring, as trees start to grow and remove carbon dioxide from the atmosphere. http://photojournal.jpl.nasa.gov/catalog/PIA20039

Carbon dioxide separation using adsorption with steam regeneration

DOEpatents

Elliott, Jeannine Elizabeth; Copeland, Robert James; Leta, Daniel P.; McCall, Patrick P.; Bai, Chuansheng; DeRites, Bruce A.

2016-11-29

A process for separating a carbon dioxide from a gas stream is disclosed. The process can include passing the gas stream over a sorbent that adsorbs the carbon dioxide by concentration swing adsorption and adsorptive displacement. The sorbent can be regenerated and the carbon dioxide recaptured by desorbing the carbon dioxide from the sorbent using concentration swing adsorption and desorptive displacement. A carbon dioxide separation system is also disclosed. Neither the system nor the process rely on temperature swing or pressure swing adsorption.

Measuring the Spectral Expression of Carbon Dioxide in the Solar Reflected Spectrum with AVIRIS

NASA Technical Reports Server (NTRS)

Green, Robert O.

2001-01-01

Carbon dioxide is a low-concentration, but important, component of the Earth's atmosphere. This gas absorbs electromagnetic radiation (EMR) in several regions of the spectrum. Absorption of energy by carbon dioxide adds heat to the atmosphere. In the world today, the burning of fossil fuels and other anthropogenic processes adds carbon dioxide to the atmosphere. Other natural processes in the Earth's system both add and remove carbon dioxide. Overall, measurements of atmospheric carbon dioxide at selected sites around the globe show an increased carbon dioxide concentration in the atmosphere. A figure shows the measured carbon dioxide from Mauna Loa, Hawaii, from 1958 to 2000. Overall, the concentration has increased from 315 to 365 ppm at this site over this period. (There is also a yearly cycle to the concentration that is timed with and hypothesized to be related to the vegetation growing season in the Northern Hemisphere.) The overall expected effect of this increase of atmospheric carbon dioxide is trapping of heat in the atmosphere and global warming. While this overall relationship between carbon dioxide and global warming seems straightforward, many of the specific details relating to regional and local sources and sinks and gradients of carbon dioxide are not well understood. A remote sensing capability to measure carbon dioxide could provide important inputs for scientific research to better understand the distribution and change in atmospheric carbon dioxide at detailed spatial and temporal levels. In pursuit of this remote sensing of carbon dioxide objective, this paper analyzes the expression of carbon dioxide in the spectral range measured by the Airborne Visible/Infrared Imagery Spectrometer (AVIRIS). Based on these analyses, a spectral-fitting algorithm that uses AVIRIS measured spectra and MODTRAN radiative-transfer code modeled spectra to derive total column carbon dioxide abundance has been developed. This algorithm has been applied to an AVIRIS data set acquired over Pasadena, California, in 1999 and a data set acquired over the Pacific Ocean near Hawaii in 2000 with promising results. This is ongoing research; the current initial analyses, measurements, and results are reported in this paper.

21 CFR 184.1240 - Carbon dioxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Carbon dioxide. 184.1240 Section 184.1240 Food and....1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2, CAS Reg. No. 124-38-9) occurs as a..., sublimes under atmospheric pressure at a temperature of −78.5 °C. Carbon dioxide is prepared as a byproduct...

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

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... marked on two sides “WARNING CO2 SOLID (DRY ICE).” (2) Other packagings containing solid carbon dioxide...

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

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 2 2012-10-01 2012-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... marked on two sides “WARNING CO2 SOLID (DRY ICE).” (2) Other packagings containing solid carbon dioxide...

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

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... marked on two sides “WARNING CO2 SOLID (DRY ICE).” (2) Other packagings containing solid carbon dioxide...

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

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 2 2014-10-01 2014-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... marked on two sides “WARNING CO2 SOLID (DRY ICE).” (2) Other packagings containing solid carbon dioxide...

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

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 2 2013-10-01 2013-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... marked on two sides “WARNING CO2 SOLID (DRY ICE).” (2) Other packagings containing solid carbon dioxide...

27 CFR 24.245 - Use of carbon dioxide in still wine.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Use of carbon dioxide in... Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still wine... of carbon dioxide per 100 milliliters of wine or where the variation results from the use of methods...

Assessment of long-term gas sampling design at two commercial manure-belt layer barns.

PubMed

Chai, Li-Long; Ni, Ji-Qin; Chen, Yan; Diehl, Claude A; Heber, Albert J; Lim, Teng T

2010-06-01

Understanding temporal and spatial variations of aerial pollutant concentrations is important for designing air quality monitoring systems. In long-term and continuous air quality monitoring in large livestock and poultry barns, these systems usually use location-shared analyzers and sensors and can only sample air at limited number of locations. To assess the validity of the gas sampling design at a commercial layer farm, a new methodology was developed to map pollutant gas concentrations using portable sensors under steady-state or quasi-steady-state barn conditions. Three assessment tests were conducted from December 2008 to February 2009 in two manure-belt layer barns. Each barn was 140.2 m long and 19.5 m wide and had 250,000 birds. Each test included four measurements of ammonia and carbon dioxide concentrations at 20 locations that covered all operating fans, including six of the fans used in the long-term sampling that represented three zones along the lengths of the barns, to generate data for complete-barn monitoring. To simulate the long-term monitoring, gas concentrations from the six long-term sampling locations were extracted from the 20 assessment locations. Statistical analyses were performed to test the variances (F-test) and sample means (t test) between the 6- and 20-sample data. The study clearly demonstrated ammonia and carbon dioxide concentration gradients that were characterized by increasing concentrations from the west to east ends of the barns following the under-cage manure-belt travel direction. Mean concentrations increased from 7.1 to 47.7 parts per million (ppm) for ammonia and from 2303 to 3454 ppm for carbon dioxide from the west to east of the barns. Variations of mean gas concentrations were much less apparent between the south and north sides of the barns, because they were 21.2 and 20.9 ppm for ammonia and 2979 and 2951 ppm for carbon dioxide, respectively. The null hypotheses that the variances and means between the 6- and 20-sample data were equal at alpha = 0.05 (P > 0.05) were accepted for both gases. The results proved that the long-term gas sampling design was valid in this instance and suggested that the gas sampling design in these two barns was one of the best on the basis of available long-term monitoring instrumentation at reasonable cost.

MHDA-Functionalized Multiwall Carbon Nanotubes for detecting non-aromatic VOCs

NASA Astrophysics Data System (ADS)

Thamri, Atef; Baccar, Hamdi; Struzzi, Claudia; Bittencourt, Carla; Abdelghani, Adnane; Llobet, Eduard

2016-10-01

The chemical modification of multiwalled carbon nanotubes (MWCNTs) with a long chain mercapto acid is reported as a way to improve sensitivity and response time of gas sensors for detecting alcohols, acetone and toxic gases such as DMMP. We have developed sensors employing MWCNTs decorated with gold nanoparticles and modified with a 16-mercaptohexadecanoic acid (MHDA) monolayer. Morphological and compositional analysis by Transmission Electron Microscopy (TEM), Fourier Transform Infra-red Spectroscopy (FTIR) and X-ray photoelectron spectroscopy were performed to characterize the gold nanoparticles and to check the bonding of the thiol monolayer. The detection of aromatic and non-aromatic volatiles and DMMP vapors by MWCNT/Au and MWCNT/Au/MHDA shows that the presence of the self-assembled layer increases sensitivity and selectivity towards non-aromatics. Furthermore, it ameliorates response dynamics, and significantly reduces nitrogen dioxide and moisture cross-sensitivity.

46 CFR 108.431 - Carbon dioxide systems: General.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Carbon dioxide systems: General. (a) Sections 108.431 through 108.457 apply to high pressure carbon dioxide fire extinguishing systems. (b) Low pressure systems, that is, those in which the carbon dioxide...

Influence of humidity on CO2 gas sensors based on polyetherimide polymer film

NASA Astrophysics Data System (ADS)

Kang, Ting; Xie, Guangzhong; Zhou, Yong; Xie, Tao; Tai, Huiling

2014-09-01

Quartz Crystal Microbalance (QCM) coated with polyetherimide (PEI) by spin coating method was applied for carbon dioxide (CO2) gas detection at room temperature in this study. The experiments were performed in dry and humid air atmospheres, and the results revealed that the prepared CO2 sensor in moisture circumstance exhibited a larger sensing response than that at dry condition. An enhanced sensing response took place for CO2 detection with the existence of water molecules. The effect of different humidity on QCM sensor performances was investigated as well in this paper. A curve, which displayed a proportional relationship between sensing response and water vapor concentration, was obtained. Moreover, the relevant sensing mechanisms were investigated.

An optically detectable CO2 sensor utilizing polyethylenimine and starch functionalized InGaN/GaN multiple quantum wells

NASA Astrophysics Data System (ADS)

Chen, Y. C.; Shih, H. Y.; Chen, J. Y.; Tan, W. J.; Chen, Y. F.

2013-07-01

An optically detectable gas sensor based on the high surface sensitivity of functionalized polyethylenimine/starch In0.15Ga0.85N/GaN strained semiconductor multiple quantum wells (MQWs) has been developed. Due to the excellent piezoelectricity of the MQWs, the change of surface charges caused by chemical interaction can introduce a strain and induce an internal field. In turn, it tilts the energy levels of the MQWs and modifies the optical properties. Through the measurement of the changes in photoluminescence as well as Raman scattering spectra under different concentrations of carbon dioxide gas, we demonstrate the feasibility and high sensitivity of the sensors derived from our methodology.

IMPROVEMENTS IN OR RELATING TO THE PRODUCTION OF SINTERED URANIUM DIOXIDE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Russell, L.E.; Harrison, J.D.L.; Brett, N.H.

A method is described for producing a dense sintered body of uranium dioxide or a mixture thereof with plutonium dioxide. Compacted uranium dioxide or a compacted uranium dioxide-plutonium dioxide mixture is heated to at least 1300 deg C in an atmosphere of carbon dioxide or carbon dioxide mixed with carbon monoxide. (R.J.S.)

Designed amyloid fibers as materials for selective carbon dioxide capture

PubMed Central

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

2014-01-01

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

46 CFR 35.40-7 - Carbon dioxide and clean agent alarms-T/ALL.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms-T/ALL. 35.40-7... Marking Requirements-TB/ALL § 35.40-7 Carbon dioxide and clean agent alarms—T/ALL. Each carbon dioxide or...: “WHEN ALARM SOUNDS VACATE AT ONCE. [CARBON DIOXIDE/CLEAN AGENT—as appropriate] BEING RELEASED.” [USCG...

27 CFR 24.245 - Use of carbon dioxide in still wine.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Use of carbon dioxide in... Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still wine... than 0.392 grams of carbon dioxide per 100 milliliters of wine. However, a tolerance of not more than 0...

46 CFR 35.40-7 - Carbon dioxide and clean agent alarms-T/ALL.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms-T/ALL. 35.40-7... Marking Requirements-TB/ALL § 35.40-7 Carbon dioxide and clean agent alarms—T/ALL. Each carbon dioxide or...: “WHEN ALARM SOUNDS VACATE AT ONCE. [CARBON DIOXIDE/CLEAN AGENT—as appropriate] BEING RELEASED.” [USCG...

A Review: Origins of the Dielectric Properties of Proteins and Potential Development as Bio-Sensors

PubMed Central

Bibi, Fabien; Villain, Maud; Guillaume, Carole; Sorli, Brice; Gontard, Nathalie

2016-01-01

Polymers can be classified as synthetic polymers and natural polymers, and are often characterized by their most typical functions namely their high mechanical resistivity, electrical conductivity and dielectric properties. This bibliography report consists in: (i) Defining the origins of the dielectric properties of natural polymers by reviewing proteins. Despite their complex molecular chains, proteins present several points of interest, particularly, their charge content conferring their electrical and dielectric properties; (ii) Identifying factors influencing the dielectric properties of protein films. The effects of vapors and gases such as water vapor, oxygen, carbon dioxide, ammonia and ethanol on the dielectric properties are put forward; (iii) Finally, potential development of protein films as bio-sensors coated on electronic devices for detection of environmental changes particularly humidity or carbon dioxide content in relation with dielectric properties variations are discussed. As the study of the dielectric properties implies imposing an electric field to the material, it was necessary to evaluate the impact of frequency on the polymers and subsequently on their structure. Characterization techniques, on the one hand dielectric spectroscopy devoted for the determination of the glass transition temperature among others, and on the other hand other techniques such as infra-red spectroscopy for structure characterization as a function of moisture content for instance are also introduced. PMID:27527179

MultiSense: A Multimodal Sensor Tool Enabling the High-Throughput Analysis of Respiration.

PubMed

Keil, Peter; Liebsch, Gregor; Borisjuk, Ljudmilla; Rolletschek, Hardy

2017-01-01

The high-throughput analysis of respiratory activity has become an important component of many biological investigations. Here, a technological platform, denoted the "MultiSense tool," is described. The tool enables the parallel monitoring of respiration in 100 samples over an extended time period, by dynamically tracking the concentrations of oxygen (O 2 ) and/or carbon dioxide (CO 2 ) and/or pH within an airtight vial. Its flexible design supports the quantification of respiration based on either oxygen consumption or carbon dioxide release, thereby allowing for the determination of the physiologically significant respiratory quotient (the ratio between the quantities of CO 2 released and the O 2 consumed). It requires an LED light source to be mounted above the sample, together with a CCD camera system, adjusted to enable the capture of analyte-specific wavelengths, and fluorescent sensor spots inserted into the sample vial. Here, a demonstration is given of the use of the MultiSense tool to quantify respiration in imbibing plant seeds, for which an appropriate step-by-step protocol is provided. The technology can be easily adapted for a wide range of applications, including the monitoring of gas exchange in any kind of liquid culture system (algae, embryo and tissue culture, cell suspensions, microbial cultures).

A flowing liquid test system for assessing the linearity and time-response of rapid fibre optic oxygen partial pressure sensors.

PubMed

Chen, R; Hahn, C E W; Farmery, A D

2012-08-15

The development of a methodology for testing the time response, linearity and performance characteristics of ultra fast fibre optic oxygen sensors in the liquid phase is presented. Two standard medical paediatric oxygenators are arranged to provide two independent extracorporeal circuits. Flow from either circuit can be diverted over the sensor under test by means of a system of rapid cross-over solenoid valves exposing the sensor to an abrupt change in oxygen partial pressure, P O2. The system is also capable of testing the oxygen sensor responses to changes in temperature, carbon dioxide partial pressure P CO2 and pH in situ. Results are presented for a miniature fibre optic oxygen sensor constructed in-house with a response time ≈ 50 ms and a commercial fibre optic sensor (Ocean Optics Foxy), when tested in flowing saline and stored blood. Copyright © 2012 Elsevier B.V. All rights reserved.

Nitric Oxide Release for Improving Performance of Implantable Chemical Sensors - A Review.

PubMed

Cha, Kyoung Ha; Wang, Xuewei; Meyerhoff, Mark E

2017-12-01

Over the last three decades, there has been extensive interest in developing in vivo chemical sensors that can provide real-time measurements of blood gases (oxygen, carbon dioxide, and pH), glucose/lactate, and potentially other critical care analytes in the blood of hospitalized patients. However, clot formation with intravascular sensors and foreign body response toward sensors implanted subcutaneously can cause inaccurate analytical results. Further, the risk of bacterial infection from any sensor implanted in the human body is another major concern. To solve these issues, the release of an endogenous gas molecule, nitric oxide (NO), from the surface of such sensors has been investigated owing to NO's ability to inhibit platelet activation/adhesion, foreign body response and bacterial growth. This paper summarizes the importance of NO's therapeutic potential for this application and reviews the publications to date that report on the analytical performance of NO release sensors in laboratory testing and/or during in vivo testing.

KSC-08pd2046

NASA Image and Video Library

2008-07-14

VANDENBERG AIR FORCE BASE, Calif. -- An Alliant motor designated for Stage 3 of a Taurus rocket is weighed by Orbital Sciences workers in Building 1555 at Vandenberg AFB. The Taurus will launch the Orbiting Carbon Observatory, or OCO, in January 2009. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. OCO will provide space-based observations of atmospheric carbon dioxide (CO2), the principal human-initiated driver of climate change. Mature technologies will be used to address NASA's highest priority carbon cycle measurement requirement. NASA's Jet Propulsion Laboratory leads the OCO effort. Orbital Sciences Corporation is providing the Taurus launch vehicle; Hamilton Sundstrand Sensor Systems, the OCO spacecraft. Photo credit: NASA/Randy Beaudoin

KSC-08pd2044

NASA Image and Video Library

2008-07-14

VANDENBERG AIR FORCE BASE, Calif. -- An Alliant motor designated for Stage 3 of a Taurus rocket is weighed by Orbital Sciences workers in Building 1555 at Vandenberg AFB. The Taurus will launch the Orbiting Carbon Observatory, or OCO, in January 2009. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. OCO will provide space-based observations of atmospheric carbon dioxide (CO2), the principal human-initiated driver of climate change. Mature technologies will be used to address NASA's highest priority carbon cycle measurement requirement. NASA's Jet Propulsion Laboratory leads the OCO effort. Orbital Sciences Corporation is providing the Taurus launch vehicle; Hamilton Sundstrand Sensor Systems, the OCO spacecraft. Photo credit: NASA/Randy Beaudoin

KSC-08pd2045

NASA Image and Video Library

2008-07-14

VANDENBERG AIR FORCE BASE, Calif. -- An Alliant motor designated for Stage 3 of a Taurus rocket is weighed by Orbital Sciences workers in Building 1555 at Vandenberg AFB. The Taurus will launch the Orbiting Carbon Observatory, or OCO, in January 2009. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. OCO will provide space-based observations of atmospheric carbon dioxide (CO2), the principal human-initiated driver of climate change. Mature technologies will be used to address NASA's highest priority carbon cycle measurement requirement. NASA's Jet Propulsion Laboratory leads the OCO effort. Orbital Sciences Corporation is providing the Taurus launch vehicle; Hamilton Sundstrand Sensor Systems, the OCO spacecraft. Photo credit: NASA/Randy Beaudoin

Carbon dioxide dangers demonstration model

USGS Publications Warehouse

Venezky, Dina; Wessells, Stephen

2010-01-01

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

Energy efficient solvent regeneration process for carbon dioxide capture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Shaojun; Meyer, Howard S.; Li, Shiguang

A process for removing carbon dioxide from a carbon dioxide-loaded solvent uses two stages of flash apparatus. Carbon dioxide is flashed from the solvent at a higher temperature and pressure in the first stage, and a lower temperature and pressure in the second stage, and is fed to a multi-stage compression train for high pressure liquefaction. Because some of the carbon dioxide fed to the compression train is already under pressure, less energy is required to further compress the carbon dioxide to a liquid state, compared to conventional processes.

Screen for Carbon Dioxide.

ERIC Educational Resources Information Center

Foster, John; And Others

1986-01-01

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

Method of immobilizing carbon dioxide from gas streams

DOEpatents

Holladay, David W.; Haag, Gary L.

1979-01-01

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

Hazardous Gas Detection Sensor Using Broadband Light-Emitting Diode-Based Absorption Spectroscopy for Space Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Terracciano, Anthony; Thurmond, Kyle; Villar, Michael

As space travel matures and extended duration voyages become increasingly common, it will be necessary to include arrays of early fire detection systems aboard spacefaring vessels, space habitats, and in spacesuits. As gasses that are relevant to combustion and pyrolysis have absorption features in the midinfrared range, it is possible to utilize absorption spectroscopy as a means of detecting and quantifying the concentration of these hazardous compounds. Within this work, a sensor for detecting carbon dioxide has been designed and tested autonomously on a high-altitude balloon flight. The sensor utilizes a 4.2-mm lightemitting diode source, amplitude modulation to characterize speciesmore » concentrations, and frequency modulation to characterize ambient temperature. Future work will include expanding the sensor design to detect other gases, and demonstrating suborbital flight capability.« less

Hazardous Gas Detection Sensor Using Broadband Light-Emitting Diode-Based Absorption Spectroscopy for Space Applications

DOE PAGES

Terracciano, Anthony; Thurmond, Kyle; Villar, Michael; ...

2018-03-12

As space travel matures and extended duration voyages become increasingly common, it will be necessary to include arrays of early fire detection systems aboard spacefaring vessels, space habitats, and in spacesuits. As gasses that are relevant to combustion and pyrolysis have absorption features in the midinfrared range, it is possible to utilize absorption spectroscopy as a means of detecting and quantifying the concentration of these hazardous compounds. Within this work, a sensor for detecting carbon dioxide has been designed and tested autonomously on a high-altitude balloon flight. The sensor utilizes a 4.2-mm lightemitting diode source, amplitude modulation to characterize speciesmore » concentrations, and frequency modulation to characterize ambient temperature. Future work will include expanding the sensor design to detect other gases, and demonstrating suborbital flight capability.« less

Carbon dioxide transport over complex terrain

USGS Publications Warehouse

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

2004-01-01

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

Continued Development of Compact Multi-Gas Monitor for Life Support Systems Control in Space

NASA Technical Reports Server (NTRS)

Delgado-Alonso, Jesus; Phillips, Straun; Berry, David; DiCarmine, Paul; Chullen, Cinda; Quinn, Gregory

2016-01-01

Miniature optical gas sensors based on luminescent materials have shown great potential as alternatives to NIR-based gas sensor systems for the Portable Life Support System (PLSS). The unique capability of luminescent sensors for carbon dioxide and oxygen monitoring under wet conditions has been reported, as has the fast recovery of humidity sensors after long periods of being wet. Lower volume and power requirements are also potential advantages over both traditional and advanced non-dispersive infrared (NDIR) gas sensors, which have so far shown longer life than luminescent sensors. In this paper we present the most recent results in the development and analytical validation of a compact multi-gas sensor unit based on luminescent sensors for the PLSS. Results of extensive testing are presented, including studies conducted in Intelligent Optical Systems laboratories, a United Technologies Corporation Aerospace Systems (UTC) laboratory, and a Johnson Space Center laboratory. The potential of this sensor technology for gas monitoring in PLSSs and other life support systems, and the advantages and limitations found through detailed sensor validation are discussed.

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

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Carbon dioxide and halon fire extinguishing systems. 147... dioxide and halon fire extinguishing systems. (a) Carbon dioxide or halon cylinders forming part of a...) Carbon dioxide or halon cylinders must be rejected for further service when they— (1) Leak; (2) Are...

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

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 5 2014-10-01 2014-10-01 false Carbon dioxide and halon fire extinguishing systems. 147... dioxide and halon fire extinguishing systems. (a) Carbon dioxide or halon cylinders forming part of a...) Carbon dioxide or halon cylinders must be rejected for further service when they— (1) Leak; (2) Are...

Carbon Dioxide Insufflation Increases Colonoscopic Adenoma Detection Rate Compared With Air Insufflation.

PubMed

Mills, Christopher D; McCamley, Chere; Swan, Michael P

2018-03-07

To determine the effect of carbon dioxide insufflation on the most important outcome measure of colonoscopic quality: adenoma detection rate (ADR). Bowel cancer is the second most common cause of cancer deaths in males and females in Australia. Carbon dioxide has in recent times become the insufflation methodology of choice for screening colonoscopy for bowel cancer, as this has been shown to have significant advantages when compared with traditional air insufflation. Endoscopies performed over a period of 9 months immediately before and after the implementation of carbon dioxide insufflation at endoscopy centers were eligible for inclusion. The difference in ADR between the carbon dioxide and air insufflation methods was statistically significant, with an increased ADR in the carbon dioxide group. The superiority of carbon dioxide insufflation was sustained with a logistic regression model, which showed ADR was significantly impacted by insufflation method. Carbon dioxide insufflation is known to reduce abdominal pain, postprocedural duration of abdominal pain, abdominal distension, and analgesic requirements. This study represents for the first time the beneficial effect of carbon dioxide insufflation upon the key quality colonoscopy indicator of ADR.

Carbon dioxide elimination and regeneration of resources in a microwave plasma torch.

PubMed

Uhm, Han S; Kwak, Hyoung S; Hong, Yong C

2016-04-01

Carbon dioxide gas as a working gas produces a stable plasma-torch by making use of 2.45 GHz microwaves. The temperature of the torch flame is measured by making use of optical spectroscopy and a thermocouple device. Two distinctive regions are exhibited, a bright, whitish region of a high-temperature zone and a bluish, dimmer region of a relatively low-temperature zone. The bright, whitish region is a typical torch based on plasma species where an analytical investigation indicates dissociation of a substantial fraction of carbon dioxide molecules, forming carbon monoxides and oxygen atoms. The emission profiles of the oxygen atoms and the carbon monoxide molecules confirm the theoretical predictions of carbon dioxide disintegration in the torch. Various hydrocarbon materials may be introduced into the carbon dioxide torch, regenerating new resources and reducing carbon dioxide concentration in the torch. As an example, coal powders in the carbon dioxide torch are converted into carbon monoxide according to the reaction of CO2 + C → 2CO, reducing a substantial amount of carbon dioxide concentration in the torch. In this regards, the microwave plasma torch may be one of the best ways of converting the carbon dioxides into useful new materials. Copyright © 2015 Elsevier Ltd. All rights reserved.

Discussion of Refrigeration Cycle Using Carbon Dioxide as Refrigerant

NASA Astrophysics Data System (ADS)

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

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

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

DOEpatents

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

2004-06-08

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

Do fossil plants signal palaeoatmospheric carbon dioxide concentration in the geological past?

PubMed Central

McElwain, J. C.

1998-01-01

Fossil, subfossil, and herbarium leaves have been shown to provide a morphological signal of the atmospheric carbon dioxide environment in which they developed by means of their stomatal density and index. An inverse relationship between stomatal density/index and atmospheric carbon dioxide concentration has been documented for all the studies to date concerning fossil and subfossil material. Furthermore, this relationship has been demonstrated experimentally by growing plants under elevated and reducedcarbon dioxide concentrations. To date, the mechanism that controls the stomatal density response to atmospheric carbon dioxide concentration remains unknown. However, stomatal parameters of fossil plants have been successfully used as a proxy indicator of palaeo-carbon dioxide levels. This paper presents new estimates of palaeo-atmospheric carbon dioxide concentrations for the Middle Eocene (Lutetian), based on the stomatal ratios of fossil Lauraceae species from Bournemouth in England. Estimates of atmospheric carbon dioxide concentrations derived from stomatal data from plants of the Early Devonian, Late Carboniferous, Early Permian and Middle Jurassic ages are reviewed in the light of new data. Semi-quantitative palaeo-carbon dioxide estimates based on the stomatal ratio (a ratio of the stomatal index of a fossil plant to that of a selected nearest living equivalent) have in the past relied on the use of a Carboniferous standard. The application of a new standard based on the present-day carbon dioxide level is reported here for comparison. The resultant ranges of palaeo-carbon dioxide estimates made from standardized fossil stomatal ratio data are in good agreement with both carbon isotopic data from terrestrial and marine sources and long-term carbon cycle modelling estimates for all the time periods studied. These data indicate elevated atmospheric carbon dioxide concentrations during the Early Devonian, Middle Jurassic and Middle Eocene, and reduced concentrations during the Late Carboniferous and Early Permian. Such data are important in demonstrating the long-term responses of plants to changing carbon dioxide concentrations and in contributing to the database needed for general circulation model climatic analogues.

Technical and economical evaluation of carbon dioxide capture and conversion to methanol process

NASA Astrophysics Data System (ADS)

Putra, Aditya Anugerah; Juwari, Handogo, Renanto

2017-05-01

Phenomenon of global warming, which is indicated by increasing of earth's surface temperature, is caused by high level of greenhouse gases level in the atmosphere. Carbon dioxide, which increases year by year because of high demand of energy, gives the largest contribution in greenhouse gases. One of the most applied solution to mitigate carbon dioxide level is post-combustion carbon capture technology. Although the technology can absorb up to 90% of carbon dioxide produced, some worries occur that captured carbon dioxide that is stored underground will be released over time. Utilizing captured carbon dioxide could be a promising solution. Captured carbon dioxide can be converted into more valuable material, such as methanol. This research will evaluate the conversion process of captured carbon dioxide to methanol, technically and economically. From the research, it is found that technically methanol can be made from captured carbon dioxide. Product gives 25.6905 kg/s flow with 99.69% purity of methanol. Economical evaluation of the whole conversion process shows that the process is economically feasible. The capture and conversion process needs 176,101,157.69 per year for total annual cost and can be overcome by revenue gained from methanol product sales.

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

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cutaneous carbon dioxide (PcCO 2) monitor. 868... dioxide (PcCO 2) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2) monitor is a noninvasive... relative changes in a hemodynamically stable patient's cutaneous carbon dioxide tension as an adjunct to...

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

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cutaneous carbon dioxide (PcCO 2) monitor. 868... dioxide (PcCO 2) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2) monitor is a noninvasive... relative changes in a hemodynamically stable patient's cutaneous carbon dioxide tension as an adjunct to...

40 CFR 60.1230 - What continuous emission monitoring systems must I install for gaseous pollutants?

Code of Federal Regulations, 2010 CFR

2010-07-01

... systems for oxygen (or carbon dioxide), sulfur dioxide, and carbon monoxide. If you operate a Class I... sulfur dioxide, nitrogen oxides, and oxygen (or carbon dioxide) at the outlet of the air pollution... according to the “Monitoring Requirements” in § 60.13. (c) You must monitor the oxygen (or carbon dioxide...

40 CFR 60.1230 - What continuous emission monitoring systems must I install for gaseous pollutants?

Code of Federal Regulations, 2011 CFR

2011-07-01

... systems for oxygen (or carbon dioxide), sulfur dioxide, and carbon monoxide. If you operate a Class I... sulfur dioxide, nitrogen oxides, and oxygen (or carbon dioxide) at the outlet of the air pollution... according to the “Monitoring Requirements” in § 60.13. (c) You must monitor the oxygen (or carbon dioxide...

Disintegration of Carbon Dioxide Molecules in a Microwave Plasma Torch.

PubMed

Kwak, Hyoung S; Uhm, Han S; Hong, Yong C; Choi, Eun H

2015-12-17

A pure carbon dioxide torch is generated by making use of 2.45 GHz microwave. Carbon dioxide gas becomes the working gas and produces a stable carbon dioxide torch. The torch volume is almost linearly proportional to the microwave power. Temperature of the torch flame is measured by making use of optical spectroscopy and thermocouple. Two distinctive regions are exhibited, a bright, whitish region of high-temperature zone and a bluish, dimmer region of relatively low-temperature zone. Study of carbon dioxide disintegration and gas temperature effects on the molecular fraction characteristics in the carbon dioxide plasma of a microwave plasma torch under atmospheric pressure is carried out. An analytical investigation of carbon dioxide disintegration indicates that substantial fraction of carbon dioxide molecules disintegrate and form other compounds in the torch. For example, the normalized particle densities at center of plasma are given by nCO2/nN = 6.12 × 10(-3), nCO/nN = 0.13, nC/nN = 0.24, nO/nN = 0.61, nC2/nN = 8.32 × 10(-7), nO2/nN = 5.39 × 10(-5), where nCO2, nCO, nC, nO, nC2, and nO2 are carbon dioxide, carbon monoxide, carbon and oxygen atom, carbon and oxygen molecule densities, respectively. nN is the neutral particle density. Emission profiles of the oxygen and carbon atom radicals and the carbon monoxide molecules confirm the theoretical predictions of carbon dioxide disintegration in the torch.

Carbon Dioxide Removal via Passive Thermal Approaches

NASA Technical Reports Server (NTRS)

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

2011-01-01

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

Continued Development of Compact Multi-gas Monitor for Life Support Systems Control in Space

NASA Technical Reports Server (NTRS)

Delgado-Alonso, Jesús; Phillips, Straun; Chullen, Cinda; Quinn, Gregory

2016-01-01

Miniature optic gas sensors (MOGS) based on luminescent materials have shown great potential as alternatives to Near-Infrared-based gas sensor systems for the advanced space suit portable life support system (PLSS). The unique capability of MOGS for carbon dioxide and oxygen monitoring under wet conditions has been reported, as has the fast recovery of MOGS humidity sensors after long periods of being wet. Lower volume and power requirements are also potential advantages of MOGS over both traditional and advanced Non-Dispersive Infrared (NDIR) gas sensors, which have shown so far longer life than luminescent sensors. This paper presents the most recent results in the development and analytical validation of a compact multi-gas sensor unit based on luminescent sensors for the PLSS. Results of extensive testing are presented, including studies conducted at Intelligent Optical Systems laboratories, a United Technology Corporation Aerospace Systems (UTAS) laboratory, and a Johnson Space Center laboratory. The potential of this sensor technology for gas monitoring in PLSSs and other life support systems and the advantages and limitations found through detailed sensor validation are discussed.

Continued Development of Compact Multi-Gas Monitor for Life Support Systems Control in Space

NASA Technical Reports Server (NTRS)

Delgado, Jesus; Phillips, Straun; Chullen, Cinda

2015-01-01

Miniature optic gas sensors (MOGS) based on luminescent materials have shown great potential as alternatives to NIR-based gas sensor systems for the Portable Life Support System (PLSS). The unique capability of MOGS for carbon dioxide and oxygen monitoring under wet conditions has been reported, as has the fast recovery of MOGS humidity sensors after long periods of being wet. Lower volume and power requirements are also potential advantages of MOGS over both traditional and advanced Non-Dispersive Infrared (NDIR) gas sensors, which have shown so far longer life than luminescent sensors. In this paper we present the most recent results in the development and analytical validation of a compact multi-gas sensor unit based on luminescent sensors for the PLSS. Results of extensive testing are presented, including studies conducted at Intelligent Optical Systems laboratories, a United Technology Corporation Aerospace Systems (UTAS) laboratory, and a Johnson Space Center laboratory. The potential of this sensor technology for gas monitoring in PLSSs and other life support systems and the advantages and limitations found through detailed sensor validation are discussed.

Inundation and Gas Fluxes from Amazon Lakes and Wetlands

NASA Astrophysics Data System (ADS)

Melack, J. M.; MacIntyre, S.; Forsberg, B. R.; Amaral, J. H.; Barbosa, P.

2015-12-01

Inundation areas and wetland habitats for the lowland Amazon basin derived remote sensing with synthetic aperture radar are combined with measurements of greenhouse gas evasion derived from field measurements and new formulations of atmosphere-water. On-going field studies in representative aquatic habitats on the central Amazon floodplain are combining monthly measurements of carbon dioxide and methane concentrations and fluxes to the atmosphere with deployment of meteorological sensors and high-resolution thermistors and optical dissolved oxygen sensors. A real-time cavity ringdown spectrometer is being used to determine the gas concentrations; vertical profiles were obtained by using an equilibrator to extract gases from water, and floating chambers are used to assess fluxes. Gas fluxes varied as a function of season, habitat and water depth. Greatest carbon dioxide fluxes occurred during high and falling water levels. During low water, periods with high chlorophyll, indicative of phytoplankton, the flux of carbon dioxide switched from being emitted from the lake to being taken-up by the lake some of the time. The highest pCO2 concentration (5500 μatm) was about three times higher than the median (1700 μatm). Higher CO2 fluxes were observed in open water than in areas with flooded or floating vegetation. In contrast, methane fluxes were higher in vegetated regions. We measured turbulence as rate of dissipation of turbulent kinetic energy based on microstructure profiling. Comparison of these measurements with those calculated from meteorological and time series measurements validated new equations for turbulent kinetic energy dissipation (TKE) rates during moderate winds and cooling and illustrated that the highest dissipation rates occurred under heating. Measured gas exchange coefficients (k600) were similar to those based on the TKE dissipation rates and are well described using the surface renewal model. These k values are several times higher than previous values applied to regional extrapolations in the Amazon basin and elsewhere.

TDLAS a laser diode sensor for the in situ monitoring of H2O, CO2 and their isotopes in the Martian atmosphere

NASA Astrophysics Data System (ADS)

Le Barbu, T.; Vinogradov, I.; Durry, G.; Korablev, O.; Chassefière, E.; Bertaux, J.-L.

2006-01-01

Within the framework of Pasteur-Exomars, we have proposed to measure in situ water vapor (H2O, HDO, H218O, H217O) and carbon dioxide (CO2, 13C16O2, 16O12C18O, 16O12C17O) isotopes and also CO, CH4 and N2O by absorption spectroscopy using near infrared laser diodes. The Service d’Aéronomie has a relevant experience in trace-gas detection with laser diodes. We have developed, with the support of the CNES and the CNRS, the SDLA diode laser spectrometer to measure in situ H2O (at 1.39 μm), CH4 (1.65 μm) and CO2 (at 1.60 μm) in the middle atmosphere from stratospheric balloons. The concentrations are obtained with a precision error of a few percent and with a high temporal resolution that ranges from 10 ms to 1 s. The developed laser probing technique should be also highly efficient to study the Martian atmosphere as there are much higher amounts of water vapor and carbon dioxide in the Martian atmosphere than in the lower stratosphere (H2O: 200 ppmv at 6 hPa on Mars, 5 ppmv at 10 hPa in the low stratosphere (LS); CO2 95% on Mars, 360 ppmv in the LS). Hence, we propose to adapt the laser probing technique to the Martian atmosphere. The main objectives are to determine water vapor and carbon dioxide fluxes and to study boundary layer properties. The sensor will provide in situ daily, diurnally resolved measurements of near-surface H2O and CO2 concentrations over seasonal time scales. The additional isotopic measurements will provide quantitative constraints on the evolution of atmospheric composition and on the history of water on Mars.

Capacitance‐Assisted Sustainable Electrochemical Carbon Dioxide Mineralisation

PubMed Central

Lamb, Katie J.; Dowsett, Mark R.; Chatzipanagis, Konstantinos; Scullion, Zhan Wei; Kröger, Roland; Lee, James D.

2017-01-01

Abstract An electrochemical cell comprising a novel dual‐component graphite and Earth‐crust abundant metal anode, a hydrogen producing cathode and an aqueous sodium chloride electrolyte was constructed and used for carbon dioxide mineralisation. Under an atmosphere of 5 % carbon dioxide in nitrogen, the cell exhibited both capacitive and oxidative electrochemistry at the anode. The graphite acted as a supercapacitive reagent concentrator, pumping carbon dioxide into aqueous solution as hydrogen carbonate. Simultaneous oxidation of the anodic metal generated cations, which reacted with the hydrogen carbonate to give mineralised carbon dioxide. Whilst conventional electrochemical carbon dioxide reduction requires hydrogen, this cell generates hydrogen at the cathode. Carbon capture can be achieved in a highly sustainable manner using scrap metal within the anode, seawater as the electrolyte, an industrially relevant gas stream and a solar panel as an effective zero‐carbon energy source. PMID:29171724

Technique for Simultaneous Determination of [35S]Sulfide and [14C]Carbon Dioxide in Anaerobic Aqueous Samples †

PubMed Central

Taylor, Craig D.; Ljungdahl, Per O.; Molongoski, John J.

1981-01-01

A technique for the simultaneous determination of [35S]sulfide and [14C]carbon dioxide produced in anaerobic aqueous samples dual-labeled with [35S]sulfate and a 14C-organic substrate is described. The method involves the passive distillation of sulfide and carbon dioxide from an acidified water sample and their subsequent separation by selective chemical absorption. The recovery of sulfide was 93% for amounts ranging from 0.35 to 50 μmol; recovery of carbon dioxide was 99% in amounts up to 20 μmol. Within these delineated ranges of total sulfide and carbon dioxide, 1 nmol of [35S]sulfide and 7.5 nmol of [14C]carbon dioxide were separated and quantified. Correction factors were formulated for low levels of radioisotopic cross-contamination by sulfide, carbon dioxide, and volatile organic acids. The overall standard error of the method was ±4% for sulfide and ±6% for carbon dioxide. PMID:16345742

Natural deep eutectic solvents (NADES) as green solvents for carbon dioxide capture

NASA Astrophysics Data System (ADS)

Mulia, Kamarza; Putri, Sylvania; Krisanti, Elsa; Nasruddin

2017-03-01

This study was conducted to determine the effectiveness of Natural Deep Eutectic Solvent (NADES), consisting of choline chloride and a hydrogen bonding donor (HBD) compound, in terms of carbon dioxide absorption. Solubility of carbon dioxide in NADES was found to be influenced HBD compound used and choline chloride to HBD ratio, carbon dioxide pressure, and contact time. HBD and choline/HBD ratios used were 1,2-propanediol (1:2), glycerol (1:2), and malic acid (1:1). The carbon dioxide absorption measurement was conducted using an apparatus that utilizes the volumetric method. Absorption curves were obtained up to pressures of 30 bar, showing a linear relationship between the amount absorbed and the final pressure of carbon dioxide. The choline and 1,2-propanediol eutectic mixture absorbs the highest amount of carbon dioxide, approaching 0.1 mole-fraction at 3.0 MPa and 50°C. We found that NADES ability to absorb carbon dioxide correlates with its polarity as tested using Nile Red as a solvatochromic probe.

A metal-free electrocatalyst for carbon dioxide reduction to multi-carbon hydrocarbons and oxygenates

NASA Astrophysics Data System (ADS)

Wu, Jingjie; Ma, Sichao; Sun, Jing; Gold, Jake I.; Tiwary, Chandrasekhar; Kim, Byoungsu; Zhu, Lingyang; Chopra, Nitin; Odeh, Ihab N.; Vajtai, Robert; Yu, Aaron Z.; Luo, Raymond; Lou, Jun; Ding, Guqiao; Kenis, Paul J. A.; Ajayan, Pulickel M.

2016-12-01

Electroreduction of carbon dioxide into higher-energy liquid fuels and chemicals is a promising but challenging renewable energy conversion technology. Among the electrocatalysts screened so far for carbon dioxide reduction, which includes metals, alloys, organometallics, layered materials and carbon nanostructures, only copper exhibits selectivity towards formation of hydrocarbons and multi-carbon oxygenates at fairly high efficiencies, whereas most others favour production of carbon monoxide or formate. Here we report that nanometre-size N-doped graphene quantum dots (NGQDs) catalyse the electrochemical reduction of carbon dioxide into multi-carbon hydrocarbons and oxygenates at high Faradaic efficiencies, high current densities and low overpotentials. The NGQDs show a high total Faradaic efficiency of carbon dioxide reduction of up to 90%, with selectivity for ethylene and ethanol conversions reaching 45%. The C2 and C3 product distribution and production rate for NGQD-catalysed carbon dioxide reduction is comparable to those obtained with copper nanoparticle-based electrocatalysts.

Effects of fuel and forest conservation on future levels of atmospheric carbon dioxide.

PubMed

Walker, J C; Kasting, J F

1992-01-01

We develop a numerical simulation of the global biogeochemical cycles of carbon that works over time scales extending from years to millions of years. The ocean is represented by warm and cold shallow water reservoirs, a thermocline reservoir, and deep Atlantic, Indian, and Pacific reservoirs. The atmosphere is characterized by a single carbon reservoir and the global biota by a single biomass reservoir. The simulation includes the rock cycle, distinguishing between shelf carbonate and pelagic carbonate precipitation, with distinct lysocline depths in the three deep ocean reservoirs. Dissolution of pelagic carbonates in response to decrease in lysocline depth is included. The simulation is tuned to reproduce the observed radiocarbon record resulting from atomic weapon testing. It is tuned also to reproduce the distribution of dissolved phosphate and total dissolved carbon between the ocean reservoirs as well as the carbon isotope ratios for both 13C and 14C in ocean and atmosphere. The simulation reproduces reasonably well the historical record of carbon dioxide partial pressure as well as the atmospheric isotope ratios for 13C and 14C over the last 200 yr as these have changed in response to fossil fuel burning and land use changes, principally forest clearance. The agreements between observation and calculation involves the assumption of a carbon dioxide fertilization effect in which the rate of production of biomass increases with increasing carbon dioxide partial pressure. At present the fertilization effect of increased carbon dioxide outweighs the effects of forest clearance, so the biota comprises an overall sink of atmospheric carbon dioxide sufficiently large to bring the budget approximately into balance. This simulation is used to examine the future evolution of carbon dioxide and its sensitivity to assumptions about the rate of fossil fuel burning and of forest clearance. Over times extending up to thousands of years, the results are insensitive to the formulation of the rock cycle and to the dissolution of deep sea carbonate sediments. Atmospheric carbon dioxide continues to increase as long fossil fuel is burned at a significant rate, because the rate of fossil fuel production of carbon dioxide far exceeds the rates at which geochemical processes can remove carbon dioxide from the atmosphere. The maximum concentration of carbon dioxide achieved in the atmosphere depends on the total amount of fossil fuel burned, but only weakly on the rate of burning. The future course of atmospheric carbon dioxide is, however, very sensitive to the fate of the forests in this simulation because of the important role assigned to carbon dioxide fertilization of plant growth rate. Forest clearance drives up atmospheric carbon dioxide not only by converting biomass into atmospheric carbon dioxide but more importantly by reducing the capacity of the biota to sequester fossil fuel carbon dioxide. In this simulation, atmospheric carbon dioxide levels could be sustained indefinitely below 500 parts per million (ppm) if fossil fuel combustion rates were immediately cut from their present value of 5 x 10(14) m/y to 0.2 x 10(14) m/y (a factor of 25 reduction) and if further forest clearance were halted. If neither of these conditions is met and if we consume most of the world's fossil fuel reserves, peak carbon dioxide concentrations of 1000-2000 ppm are probable within the next few centuries.

Fabrication of a sensing module using micromachined biosensors.

PubMed

Suzuki, H; Arakawa, H; Karube, I

2001-12-01

Micromachining is a powerful tool in constructing micro biosensors and micro systems which incorporate them. A sensing module for blood components was fabricated using the technology. The analytes include glucose, urea, uric acid, creatine, and creatinine. Transducers used to construct the corresponding sensors were a Severinghaus-type carbon dioxide electrode for the urea sensor and a Clark-type oxygen electrode for the other analytes. In these electrodes, detecting electrode patterns were formed on a glass substrate by photolithography and the micro container for the internal electrolyte solution was formed on a silicon substrate by anisotropic etching. A through-hole was formed in the sensitive area, where a silicone gas-permeable membrane was formed and an enzyme was immobilized. The sensors were characterized in terms of pH and temperature dependence and calibration curves along with detection limits. Furthermore, the sensors were incorporated in an acrylate flow cell. Simultaneous operation of these sensors was successfully conducted and distinct and stable responses were observed for respective sensors.

Three-gas detection system with IR optical sensor based on NDIR technology

NASA Astrophysics Data System (ADS)

Tan, Qiulin; Tang, Licheng; Yang, Mingliang; Xue, Chenyang; Zhang, Wendong; Liu, Jun; Xiong, Jijun

2015-11-01

In this paper, a three-gas detection system with a environmental parameter compensation method is proposed based on Non-dispersive infra-red (NDIR) technique, which can be applied to detect multi-gas (methane, carbon dioxide and carbon monoxide). In this system, an IR source and four single-channel pyroelectric sensors are integrated in the miniature optical gas chamber successfully. Inner wall of the chamber coated with Au film is designed as paraboloids. The infrared light is reflected twice before reaching to detectors, thus increasing optical path. Besides, a compensation method is presented to overcome the influence in variation of environment (ambient temperature, humidity and pressure), thus leading to improve the accuracy in gas detection. Experimental results demonstrated that detection ranges are 0-50,000 ppm for CH4, 0-44,500 ppm for CO, 0-48,000 ppm for CO2 and the accuracy is ±0.05%.

Indoor air quality analysis based on Hadoop

NASA Astrophysics Data System (ADS)

Tuo, Wang; Yunhua, Sun; Song, Tian; Liang, Yu; Weihong, Cui

2014-03-01

The air of the office environment is our research object. The data of temperature, humidity, concentrations of carbon dioxide, carbon monoxide and ammonia are collected peer one to eight seconds by the sensor monitoring system. And all the data are stored in the Hbase database of Hadoop platform. With the help of HBase feature of column-oriented store and versioned (automatically add the time column), the time-series data sets are bulit based on the primary key Row-key and timestamp. The parallel computing programming model MapReduce is used to process millions of data collected by sensors. By analysing the changing trend of parameters' value at different time of the same day and at the same time of various dates, the impact of human factor and other factors on the room microenvironment is achieved according to the liquidity of the office staff. Moreover, the effective way to improve indoor air quality is proposed in the end of this paper.

21 CFR 184.1240 - Carbon dioxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Carbon dioxide. 184.1240 Section 184.1240 Food and... Substances Affirmed as GRAS § 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2, CAS Reg. No.... The solid form, dry ice, sublimes under atmospheric pressure at a temperature of −78.5 °C. Carbon...

21 CFR 184.1240 - Carbon dioxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Carbon dioxide. 184.1240 Section 184.1240 Food and... Substances Affirmed as GRAS § 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2, CAS Reg. No.... The solid form, dry ice, sublimes under atmospheric pressure at a temperature of −78.5 °C. Carbon...

21 CFR 184.1240 - Carbon dioxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Carbon dioxide. 184.1240 Section 184.1240 Food and... Substances Affirmed as GRAS § 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2, CAS Reg. No.... The solid form, dry ice, sublimes under atmospheric pressure at a temperature of −78.5 °C. Carbon...

21 CFR 868.5300 - Carbon dioxide absorbent.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for medical purposes that consists of an...

21 CFR 868.5300 - Carbon dioxide absorbent.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for medical purposes that consists of an...

21 CFR 868.5300 - Carbon dioxide absorbent.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for medical purposes that consists of an...

46 CFR 193.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 193.15-20 Carbon dioxide storage. (a...

46 CFR 193.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 193.15-20 Carbon dioxide storage. (a...

Development of a Prototype Algal Reactor for Removing CO2 from Cabin Air

NASA Technical Reports Server (NTRS)

Patel, Vrajen; Monje, Oscar

2013-01-01

Controlling carbon dioxide in spacecraft cabin air may be accomplished using algal photobioreactors (PBRs). The purpose of this project was to evaluate the use of a commercial microcontroller, the Arduino Mega 2560, for measuring key photioreactor variables: dissolved oxygen, pH, temperature, light, and carbon dioxide. The Arduino platform is an opensource physical computing platform composed of a compact microcontroller board and a C++/C computer language (Arduino 1.0.5). The functionality of the Arduino platform can be expanded by the use of numerous add-ons or 'shields'. The Arduino Mega 2560 was equipped with the following shields: datalogger, BNC shield for reading pH sensor, a Mega Moto shield for controlling CO2 addition, as well as multiple sensors. The dissolved oxygen (DO) probe was calibrated using a nitrogen bubbling technique and the pH probe was calibrated via an Omega pH simulator. The PBR was constructed using a 2 L beaker, a 66 L box for addition of CO2, a micro porous membrane, a diaphragm pump, four 25 watt light bulbs, a MasterFiex speed controller, and a fan. The algae (wild type Synechocystis PCC6803) was grown in an aerated flask until the algae was dense enough to used in the main reactor. After the algae was grown, it was transferred to the 2 L beaker where CO2 consumption and O2 production was measured using the microcontroller sensor suite. The data was recorded via the datalogger and transferred to a computer for analysis.

TRPs as chemosensors (ROS, RNS, RCS, gasotransmitters).

PubMed

Shimizu, Shunichi; Takahashi, Nobuaki; Mori, Yasuo

2014-01-01

The transient receptor potential (trp) gene superfamily encodes TRP proteins that act as multimodal sensor cation channels for a wide variety of stimuli from outside and inside the cell. Upon chemical or physical stimulation of cells, TRP channels transduce electrical and/or Ca(2+) signals via their cation channel activities. These functional features of TRP channels allow the body to react and adapt to different forms of environmental changes. Indeed, members of one class of TRP channels have emerged as sensors of reactive oxygen species (ROS), reactive nitrogen species (RNS), reactive carbonyl species (RCS), and gaseous messenger molecules including molecular oxygen (O2), hydrogen sulfide (H2S), and carbon dioxide (CO2). Hydrogen peroxide (H2O2), an ROS, triggers the production of ADP-ribose, which binds and activates TRPM2. In addition to TRPM2, TRPC5, TRPV1, and TRPA1 are also activated by H2O2 via modification of cysteine (Cys) free sulfhydryl groups. Nitric oxide (NO), a vasoactive gaseous molecule, regulates TRP channels directly via Cys S-nitrosylation or indirectly via cyclic GMP (cGMP)/protein kinase G (PKG)-dependent phosphorylation. Anoxia induced by O2-glucose deprivation and severe hypoxia activates TRPM7 and TRPC6, respectively, whereas TRPA1 serves as a sensor of mild hypoxia and hyperoxia in vagal and sensory neurons. TRPA1 also detects other gaseous molecules, such as hydrogen sulfide (H2S) and carbon dioxide (CO2). In this review, we highlight our current knowledge of TRP channels as chemosensors for ROS, RNS, RCS, and gaseous molecules and discuss their functional impacts on physiological and pathological events.

U.S. Energy-Related Carbon Dioxide Emissions

EIA Publications

2017-01-01

U.S. Energy Information Administration releases its online analysis of 2016 energy-related carbon dioxide emissions today. It indicates U.S. carbon dioxide emissions from the consumption of fossil fuels were 5,170 million metric tons carbon dioxide in 2016, a decrease of 1.7 percent from the 2015 level. Energy-related carbon dioxide emissions have declined in six of the last ten years. This analysis is based on data contained in the August 2017 Monthly Energy Review.

Disintegration of Carbon Dioxide Molecules in a Microwave Plasma Torch

PubMed Central

Kwak, Hyoung S.; Uhm, Han S.; Hong, Yong C.; Choi, Eun H.

2015-01-01

A pure carbon dioxide torch is generated by making use of 2.45 GHz microwave. Carbon dioxide gas becomes the working gas and produces a stable carbon dioxide torch. The torch volume is almost linearly proportional to the microwave power. Temperature of the torch flame is measured by making use of optical spectroscopy and thermocouple. Two distinctive regions are exhibited, a bright, whitish region of high-temperature zone and a bluish, dimmer region of relatively low-temperature zone. Study of carbon dioxide disintegration and gas temperature effects on the molecular fraction characteristics in the carbon dioxide plasma of a microwave plasma torch under atmospheric pressure is carried out. An analytical investigation of carbon dioxide disintegration indicates that substantial fraction of carbon dioxide molecules disintegrate and form other compounds in the torch. For example, the normalized particle densities at center of plasma are given by nCO2/nN = 6.12 × 10−3, nCO/nN = 0.13, nC/nN = 0.24, nO/nN = 0.61, nC2/nN = 8.32 × 10−7, nO2/nN = 5.39 × 10−5, where nCO2, nCO, nC, nO, nC2, and nO2 are carbon dioxide, carbon monoxide, carbon and oxygen atom, carbon and oxygen molecule densities, respectively. nN is the neutral particle density. Emission profiles of the oxygen and carbon atom radicals and the carbon monoxide molecules confirm the theoretical predictions of carbon dioxide disintegration in the torch. PMID:26674957

Low-Cost, Distributed Environmental Monitors for Factory Worker Health

PubMed Central

Thomas, Geb W.; Sousan, Sinan; Tatum, Marcus; Liu, Xiaoxing; Zuidema, Christopher; Fitzpatrick, Mitchell; Koehler, Kirsten A.; Peters, Thomas M.

2018-01-01

An integrated network of environmental monitors was developed to continuously measure several airborne hazards in a manufacturing facility. The monitors integrated low-cost sensors to measure particulate matter, carbon monoxide, ozone and nitrogen dioxide, noise, temperature and humidity. The monitors were developed and tested in situ for three months in several overlapping deployments, before a full cohort of 40 was deployed in a heavy vehicle manufacturing facility for a year of data collection. The monitors collect data from each sensor and report them to a central database every 5 min. The work includes an experimental validation of the particle, gas and noise monitors. The R2 for the particle sensor ranges between 0.98 and 0.99 for particle mass densities up to 300 μg/m3. The R2 for the carbon monoxide sensor is 0.99 for concentrations up to 15 ppm. The R2 for the oxidizing gas sensor is 0.98 over the sensitive range from 20 to 180 ppb. The noise monitor is precise within 1% between 65 and 95 dBA. This work demonstrates the capability of distributed monitoring as a means to examine exposure variability in both space and time, building an important preliminary step towards a new approach for workplace hazard monitoring. PMID:29751534

Development and Measurements of a Mid-Infrared Multi-Gas Sensor System for CO, CO₂ and CH₄ Detection.

PubMed

Dong, Ming; Zheng, Chuantao; Miao, Shuzhuo; Zhang, Yu; Du, Qiaoling; Wang, Yiding; Tittel, Frank K

2017-09-27

A multi-gas sensor system was developed that uses a single broadband light source and multiple carbon monoxide (CO), carbon dioxide (CO₂) and methane (CH₄) pyroelectric detectors by use of the time division multiplexing (TDM) technique. A stepper motor-based rotating system and a single-reflection spherical optical mirror were designed and adopted to realize and enhance multi-gas detection. Detailed measurements under static detection mode (without rotation) and dynamic mode (with rotation) were performed to study the performance of the sensor system for the three gas species. Effects of the motor rotating period on sensor performances were also investigated and a rotation speed of 0.4π rad/s was required to obtain a stable sensing performance, corresponding to a detection period of ~10 s to realize one round of detection. Based on an Allan deviation analysis, the 1 σ detection limits under static operation are 2.96, 4.54 and 2.84 parts per million in volume (ppmv) for CO, CO₂ and CH₄, respectively and the 1 σ detection limits under dynamic operations are 8.83, 8.69 and 10.29 ppmv for the three gas species, respectively. The reported sensor has potential applications in various fields requiring CO, CO₂ and CH₄ detection such as in coal mines.

New study on the correlation between carbon dioxide concentration in the environment and radon monitor devices.

PubMed

Shahrokhi, A; Burghele, B D; Fábián, F; Kovács, T

2015-12-01

The influence of high geogenic carbon dioxide concentrations on monitoring devices might present a significant challenge to the measurement of radon concentrations in environments with a high level of carbon dioxide concentration such as volcano sites, mofettes, caves, etc. In this study, the influence of carbon dioxide concentration on several different types of radon monitor devices - including Alpha Spectrometry (Sarad RTM 2200, EQF 3220, RAD7), Ionizing Chamber (AlphaGUARD PQ2000 PRO) and Active Cell (Active scintillation cell, Pylon 300A) - was examined to represent new aspects of radon measuring in environments with carbon dioxide. In light of the results, all measuring devices were exposed to variable conditions affected by carbon dioxide concentration, except for the AlphaGUARD, which was kept in a steady state throughout the experiment. It was observed that alpha spectroscopy devices were affected by carbon dioxide, since measured radon concentrations decreased in the presence of 70% and 90% carbon dioxide concentrations by 26.5 ± 2% and 14.5 ± 2.5% for EQF 3220, and 32 ± 2% and 35.5 ± 2% for RTM 2200. However, the ionizing chamber instrument was unaffected by changes in carbon dioxide concentration. It was determined that the RAD7 performed relatively inefficiently in the presence of carbon dioxide concentrations higher than 67% by an overall efficiency factor of approximately 0.52, confirming that it is not an admissible radon monitor instrument in environments with high carbon dioxide concentrations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Utilizing Diffusion Theory to predict carbon dioxide concentration in an indoor environment

NASA Astrophysics Data System (ADS)

Kramer, Andrew R.

This research details a new method of relating sources of carbon dioxide to carbon dioxide concentration in a room operating in a reduced ventilation mode by utilizing Diffusion Theory. The theoretical basis of this research involved solving Fick's Second Law of Diffusion in spherical coordinates for a source of carbon dioxide flowing at a constant rate and located in the center of an impermeable spherical boundary. The solution was developed using a Laplace Transformation. A spherical diffusion test chamber was constructed and used to validate and benchmark the developed theory. The method was benchmarked by using Dispersion Coefficients for large carbon dioxide flow rates due to diffusion induced convection. The theoretical model was adapted to model a room operating with restricted ventilation in the presence of a known, constant source of carbon dioxide. The room was modeled as a sphere of volume equal to the room and utilized a Dispersion Coefficient that is consistent with published values. The developed Diffusion Model successfully predicted the spatial concentration of carbon dioxide in a room operating in a reduced ventilation mode in the presence of a source of carbon dioxide. The flow rates of carbon dioxide that were used in the room are comparable to the average flow rate of carbon dioxide from a person during quiet breathing, also known as the Tidal Breathing. This indicates the Diffusion Model developed from this research has the potential to correlate carbon dioxide concentration with static occupancy levels which can lead to energy savings through a reduction in air exchange rates when low occupancy is detected.

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

NASA Technical Reports Server (NTRS)

Hagedorn, Norman H. (Inventor)

1993-01-01

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

Capacitance-Assisted Sustainable Electrochemical Carbon Dioxide Mineralisation.

PubMed

Lamb, Katie J; Dowsett, Mark R; Chatzipanagis, Konstantinos; Scullion, Zhan Wei; Kröger, Roland; Lee, James D; Aguiar, Pedro M; North, Michael; Parkin, Alison

2018-01-10

An electrochemical cell comprising a novel dual-component graphite and Earth-crust abundant metal anode, a hydrogen producing cathode and an aqueous sodium chloride electrolyte was constructed and used for carbon dioxide mineralisation. Under an atmosphere of 5 % carbon dioxide in nitrogen, the cell exhibited both capacitive and oxidative electrochemistry at the anode. The graphite acted as a supercapacitive reagent concentrator, pumping carbon dioxide into aqueous solution as hydrogen carbonate. Simultaneous oxidation of the anodic metal generated cations, which reacted with the hydrogen carbonate to give mineralised carbon dioxide. Whilst conventional electrochemical carbon dioxide reduction requires hydrogen, this cell generates hydrogen at the cathode. Carbon capture can be achieved in a highly sustainable manner using scrap metal within the anode, seawater as the electrolyte, an industrially relevant gas stream and a solar panel as an effective zero-carbon energy source. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

21 CFR 582.1240 - Carbon dioxide.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is generally...

40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Complete Heavy-Duty Vehicles; Test Procedures § 86.124-78 Carbon dioxide analyzer calibration. Prior to its introduction into service and monthly thereafter the NDIR carbon dioxide analyzer shall be calibrated: (a...

40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.524-78 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service and monthly thereafter the NDIR carbon dioxide...

21 CFR 884.1300 - Uterotubal carbon dioxide insufflator and accessories.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Uterotubal carbon dioxide insufflator and... Gynecological Diagnostic Devices § 884.1300 Uterotubal carbon dioxide insufflator and accessories. (a) Identification. A uterotubal carbon dioxide insufflator and accessories is a device used to test the patency...

27 CFR 24.319 - Carbon dioxide record.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Carbon dioxide record. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted to...

46 CFR 95.15-60 - Odorizing units.

Code of Federal Regulations, 2012 CFR

2012-10-01

... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-60 Odorizing units. Each carbon dioxide... the scent of wintergreen, the detection of which will serve as an indication that carbon dioxide gas is present in a protected area and any other area into which the carbon dioxide may migrate. “Altered...

21 CFR 582.1240 - Carbon dioxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is generally...

21 CFR 582.1240 - Carbon dioxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is generally...

46 CFR 76.15-60 - Odorizing units.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Carbon Dioxide Extinguishing Systems, Details § 76.15-60 Odorizing units. Each carbon dioxide... the scent of wintergreen, the detection of which will serve as an indication that carbon dioxide gas is present in a protected area and any other area into which the carbon dioxide may migrate. “Altered...

27 CFR 24.319 - Carbon dioxide record.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Carbon dioxide record. 24..., DEPARTMENT OF THE TREASURY ALCOHOL WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted to...

27 CFR 24.319 - Carbon dioxide record.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Carbon dioxide record. 24..., DEPARTMENT OF THE TREASURY ALCOHOL WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted to...

27 CFR 24.319 - Carbon dioxide record.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Carbon dioxide record. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted to...

46 CFR 193.15-17 - Odorizing units.

Code of Federal Regulations, 2014 CFR

2014-10-01

... EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-17 Odorizing units. Each carbon dioxide extinguishing system installed or altered after July 9, 2013, must have an approved... carbon dioxide gas is present in a protected area and any other area into which the carbon dioxide may...

40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Carbon dioxide analyzer calibration... Complete Heavy-Duty Vehicles; Test Procedures § 86.124-78 Carbon dioxide analyzer calibration. Prior to its introduction into service and monthly thereafter the NDIR carbon dioxide analyzer shall be calibrated: (a...

46 CFR 193.15-17 - Odorizing units.

Code of Federal Regulations, 2013 CFR

2013-10-01

... EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-17 Odorizing units. Each carbon dioxide extinguishing system installed or altered after July 9, 2013, must have an approved... carbon dioxide gas is present in a protected area and any other area into which the carbon dioxide may...

46 CFR 76.15-60 - Odorizing units.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Carbon Dioxide Extinguishing Systems, Details § 76.15-60 Odorizing units. Each carbon dioxide... the scent of wintergreen, the detection of which will serve as an indication that carbon dioxide gas is present in a protected area and any other area into which the carbon dioxide may migrate. “Altered...

21 CFR 582.1240 - Carbon dioxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is generally...

21 CFR 884.1300 - Uterotubal carbon dioxide insufflator and accessories.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Uterotubal carbon dioxide insufflator and... Gynecological Diagnostic Devices § 884.1300 Uterotubal carbon dioxide insufflator and accessories. (a) Identification. A uterotubal carbon dioxide insufflator and accessories is a device used to test the patency...

46 CFR 76.15-60 - Odorizing units.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Carbon Dioxide Extinguishing Systems, Details § 76.15-60 Odorizing units. Each carbon dioxide... the scent of wintergreen, the detection of which will serve as an indication that carbon dioxide gas is present in a protected area and any other area into which the carbon dioxide may migrate. “Altered...

40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration... Complete Heavy-Duty Vehicles; Test Procedures § 86.124-78 Carbon dioxide analyzer calibration. Prior to its introduction into service and monthly thereafter the NDIR carbon dioxide analyzer shall be calibrated: (a...

21 CFR 884.1300 - Uterotubal carbon dioxide insufflator and accessories.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Uterotubal carbon dioxide insufflator and... Gynecological Diagnostic Devices § 884.1300 Uterotubal carbon dioxide insufflator and accessories. (a) Identification. A uterotubal carbon dioxide insufflator and accessories is a device used to test the patency...

27 CFR 24.319 - Carbon dioxide record.

Code of Federal Regulations, 2011 CFR

2011-04-01

..., DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted to... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Carbon dioxide record. 24...

21 CFR 582.1240 - Carbon dioxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is generally... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS...

46 CFR 76.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 3 2013-10-01 2013-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as...

46 CFR 95.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a...

46 CFR 76.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 3 2011-10-01 2011-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as...

46 CFR 95.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a...

46 CFR 76.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 3 2012-10-01 2012-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as...

46 CFR 95.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a...

46 CFR 76.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 3 2014-10-01 2014-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as...

Transition Organometallic Heterobimettalic Microns-Carbon Dioxide and Microns-Format Complexes in Homogeneous Carbon Dioxide Fixation

DTIC Science & Technology

1992-08-12

AD-A254 538 OFFICE OF NAVAL RESEARCH FINAL REPORT FCR Contract N00014-87-K-0465 R&T Code 413j006 "Transition Organometallic Heterobimetallic ix...ransition Organometallic Heterobimetallic P-Carbon Dioxide and p-FormateComplexes in Homogeneous Carbon Dioxide Fixation 12. PERSONAL AUTHOR(S) Alan R...J. L. Shibley, and A. R. Cutler, J. Organomet. Chem. 1989,378, 421.* "Characterization of the Heterobimetallic ±(r011-C: T12 -O,O’) Carbon Dioxide

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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

Water Sensors

NASA Technical Reports Server (NTRS)

1992-01-01

Mike Morris, former Associate Director of STAC, formed pHish Doctor, Inc. to develop and sell a pH monitor for home aquariums. The monitor, or pHish Doctor, consists of a sensor strip and color chart that continually measures pH levels in an aquarium. This is important because when the level gets too high, ammonia excreted by fish is highly toxic; at low pH, bacteria that normally break down waste products stop functioning. Sales have run into the tens of thousands of dollars. A NASA Tech Brief Technical Support Package later led to a salt water version of the system and a DoE Small Business Innovation Research (SBIR) grant for development of a sensor for sea buoys. The company, now known as Ocean Optics, Inc., is currently studying the effects of carbon dioxide buildup as well as exploring other commercial applications for the fiber optic sensor.

Advances in Hydrogen, Carbon Dioxide, and Hydrocarbon Gas Sensor Technology Using GaN and ZnO-Based Devices

PubMed Central

Anderson, Travis; Ren, Fan; Pearton, Stephen; Kang, Byoung Sam; Wang, Hung-Ta; Chang, Chih-Yang; Lin, Jenshan

2009-01-01

In this paper, we review our recent results in developing gas sensors for hydrogen using various device structures, including ZnO nanowires and GaN High Electron Mobility Transistors (HEMTs). ZnO nanowires are particularly interesting because they have a large surface area to volume ratio, which will improve sensitivity, and because they operate at low current levels, will have low power requirements in a sensor module. GaN-based devices offer the advantage of the HEMT structure, high temperature operation, and simple integration with existing fabrication technology and sensing systems. Improvements in sensitivity, recoverability, and reliability are presented. Also reported are demonstrations of detection of other gases, including CO2 and C2H4 using functionalized GaN HEMTs. This is critical for the development of lab-on-a-chip type systems and can provide a significant advance towards a market-ready sensor application. PMID:22408548

Novel Carbon Dioxide Microsensor Based on Tin Oxide Nanomaterial Doped With Copper Oxide

NASA Technical Reports Server (NTRS)

Xu, Jennifer C.; Hunter, Gary W.; Lukco, Dorothy; Liu, Chung-Chiun; Ward, Benjamin J.

2008-01-01

Carbon dioxide (CO2) is one of the major indicators of fire and therefore its measurement is very important for low-false-alarm fire detection and emissions monitoring. However, only a limited number of CO2 sensing materials exist due to the high chemical stability of CO2. In this work, a novel CO2 microsensor based on nanocrystalline tin oxide (SnO2) doped with copper oxide (CuO) has been successfully demonstrated. The CuO-SnO2 based CO2 microsensors are fabricated by means of microelectromechanical systems (MEMS) technology and sol-gel nanomaterial-synthesis processes. At a doping level of CuO: SnO2 = 1:8 (molar ratio), the resistance of the sensor has a linear response to CO2 concentrations for the range of 1 to 4 percent CO2 in air at 450 C. This approach has demonstrated the use of SnO2, typically used for the detection of reducing gases, in the detection of an oxidizing gas.

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

USGS Publications Warehouse

Colt, John; Watten, Barnaby; Pfeiffer, Tim

2012-01-01

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

A strategic decision-making model considering the social costs of carbon dioxide emissions for sustainable supply chain management.

PubMed

Tseng, Shih-Chang; Hung, Shiu-Wan

2014-01-15

Incorporating sustainability into supply chain management has become a critical issue driven by pressures from governments, customers, and various stakeholder groups over the past decade. This study proposes a strategic decision-making model considering both the operational costs and social costs caused by the carbon dioxide emissions from operating such a supply chain network for sustainable supply chain management. This model was used to evaluate carbon dioxide emissions and operational costs under different scenarios in an apparel manufacturing supply chain network. The results showed that the higher the social cost rate of carbon dioxide emissions, the lower the amount of the emission of carbon dioxide. The results also suggested that a legislation that forces the enterprises to bear the social costs of carbon dioxide emissions resulting from their economic activities is an effective approach to reducing carbon dioxide emissions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Semiconductor-Based Photoelectrochemical Conversion of Carbon Dioxide: Stepping Towards Artificial Photosynthesis.

PubMed

Pang, Hong; Masuda, Takuya; Ye, Jinhua

2018-01-18

The photoelectrochemical (PEC) carbon dioxide reduction process stands out as a promising avenue for the conversion of solar energy into chemical feedstocks, among various methods available for carbon dioxide mitigation. Semiconductors derived from cheap and abundant elements are interesting candidates for catalysis. Whether employed as intrinsic semiconductors or hybridized with metallic cocatalysts, biocatalysts, and metal molecular complexes, semiconductor photocathodes exhibit good performance and low overpotential during carbon dioxide reduction. Apart from focusing on carbon dioxide reduction materials and chemistry, PEC cells towards standalone devices that use photohybrid electrodes or solar cells have also been a hot topic in recent research. An overview of the state-of-the-art progress in PEC carbon dioxide reduction is presented and a deep understanding of the catalysts of carbon dioxide reduction is also given. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of carbon dioxide on Penicillium chrysogenum: an autoradiographic study

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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

The Formation of Ethane from Carbon Dioxide under Cold Plasma

NASA Astrophysics Data System (ADS)

Zhang, Xiu-ling; Zhang, Lin; Dai, Bin; Gong, Wei-min; Liu, Chang-hou

2001-04-01

Pulsed-corona plasma has been used as a new method for ethane dehydrogenation at low temperature and normal pressure using carbon dioxide as an oxidant in this paper. The effect of carbon dioxide content in the feed, power input, and flow rate of the reactants on the ethane dehydrogenation has been investigated. The experimental results show that the conversion of ethane increases with the increase in the amount of carbon dioxide in the feed. The yield of ethylene and acetylene decreases with the increase in the yield of carbon monoxide, indicating that the increased carbon dioxide leads to the part of ethylene and acetylene being oxidized to carbon monoxide. Power input is primarily an electrical parameter in pulsed-corona plasma, which plays an important role in reactant conversion and product formation. When the power input reaches 16 W, ethane conversion is 41.0% and carbon dioxide conversion is 26.3%. The total yield of ethylene and acetylene is 15.6%. The reduced flow rate of feed improves the conversion of ethane, carbon dioxide and the yield of acetylene, and induces carbon deposit as well.

21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO2) monitor.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cutaneous carbon dioxide (PcCO2) monitor. 868.2480... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2480 Cutaneous carbon dioxide (PcCO2) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2) monitor is a noninvasive heated...

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

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Carbon dioxide; exemption from the... Exemptions From Tolerances § 180.1049 Carbon dioxide; exemption from the requirement of a tolerance. The insecticide carbon dioxide is exempted from the requirement of a tolerance when used after harvest in modified...

21 CFR 868.5310 - Carbon dioxide absorber.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in a...

21 CFR 868.5310 - Carbon dioxide absorber.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in a...

21 CFR 201.161 - Carbon dioxide and certain other gases.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 4 2014-04-01 2014-04-01 false Carbon dioxide and certain other gases. 201.161... (CONTINUED) DRUGS: GENERAL LABELING Other Exemptions § 201.161 Carbon dioxide and certain other gases. (a) Carbon dioxide, cyclopropane, ethylene, helium, and nitrous oxide gases intended for drug use are...

27 CFR 26.222 - Still wines containing carbon dioxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

... carbon dioxide. 26.222 Section 26.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From the Virgin Islands § 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine...

27 CFR 26.222 - Still wines containing carbon dioxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... carbon dioxide. 26.222 Section 26.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From the Virgin Islands § 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine...

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

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Carbon dioxide; exemption from the... Exemptions From Tolerances § 180.1049 Carbon dioxide; exemption from the requirement of a tolerance. The insecticide carbon dioxide is exempted from the requirement of a tolerance when used after harvest in modified...

21 CFR 201.161 - Carbon dioxide and certain other gases.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 4 2013-04-01 2013-04-01 false Carbon dioxide and certain other gases. 201.161... (CONTINUED) DRUGS: GENERAL LABELING Other Exemptions § 201.161 Carbon dioxide and certain other gases. (a) Carbon dioxide, cyclopropane, ethylene, helium, and nitrous oxide gases intended for drug use are...

21 CFR 868.5310 - Carbon dioxide absorber.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in a...

27 CFR 26.222 - Still wines containing carbon dioxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

... carbon dioxide. 26.222 Section 26.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From the Virgin Islands § 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine...

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

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Indwelling blood carbon dioxide partial pressure....1150 Indwelling blood carbon dioxide partial pressure (PCO2) analyzer. (a) Identification. An indwelling blood carbon dioxide partial pressure PCO2 analyzer is a device that consists of a catheter-tip...

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

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Indwelling blood carbon dioxide partial pressure....1150 Indwelling blood carbon dioxide partial pressure (PCO2) analyzer. (a) Identification. An indwelling blood carbon dioxide partial pressure PCO2 analyzer is a device that consists of a catheter-tip...

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

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Indwelling blood carbon dioxide partial pressure....1150 Indwelling blood carbon dioxide partial pressure (PCO2) analyzer. (a) Identification. An indwelling blood carbon dioxide partial pressure PCO2 analyzer is a device that consists of a catheter-tip...

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

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Indwelling blood carbon dioxide partial pressure....1150 Indwelling blood carbon dioxide partial pressure (PCO2) analyzer. (a) Identification. An indwelling blood carbon dioxide partial pressure PCO2 analyzer is a device that consists of a catheter-tip...

21 CFR 868.5310 - Carbon dioxide absorber.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a devic...

46 CFR 169.565 - Fixed carbon dioxide system.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Lifesaving and Firefighting Equipment Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide...

46 CFR 108.431 - Carbon dioxide systems: General.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a)...

46 CFR 169.565 - Fixed carbon dioxide system.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Lifesaving and Firefighting Equipment Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide...

46 CFR 108.431 - Carbon dioxide systems: General.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a)...

21 CFR 868.1400 - Carbon dioxide gas analyzer.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868.1400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer...

46 CFR 193.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-20 Carbon dioxide storage. (a) Except as provided in...

46 CFR 108.627 - Carbon dioxide alarm.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide alarm. 108.627 Section 108.627 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide alarm. Each carbon dioxide alarm must be identified by marking: “WHEN ALARM...

46 CFR 108.431 - Carbon dioxide systems: General.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a)...

46 CFR 108.431 - Carbon dioxide systems: General.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a)...

46 CFR 169.565 - Fixed carbon dioxide system.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Lifesaving and Firefighting Equipment Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide...

21 CFR 868.5300 - Carbon dioxide absorbent.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carbon dioxide absorbent. 868.5300 Section 868.5300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a...

21 CFR 868.5300 - Carbon dioxide absorbent.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carbon dioxide absorbent. 868.5300 Section 868.5300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a...

21 CFR 868.5310 - Carbon dioxide absorber.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a devic...

27 CFR 26.222 - Still wines containing carbon dioxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

... carbon dioxide. 26.222 Section 26.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From the Virgin Islands § 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine...

Process for sequestering carbon dioxide and sulfur dioxide

DOEpatents

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

2009-10-20

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

Effect of Carbon Dioxide on Testing of Susceptibilities of Respiratory Tract Pathogens to Macrolide and Azalide Antimicrobial Agents

PubMed Central

Johnson, M. M.; Hill, S. L.; Piddock, Laura J. V.

1999-01-01

The in vitro activities of erythromycin, azithromycin, and clarithromycin against 178 clinical isolates from the lower respiratory tract of patients with chronic obstructive pulmonary disease were determined by an agar dilution method. The plates were incubated in air alone or in 5% carbon dioxide. The MICs measured in air alone were lower for most isolates than those measured in 5% carbon dioxide, illustrating the “pH effect” of incubation in carbon dioxide. Testing of isolates in 5% carbon dioxide on pH-adjusted medium (pH 8.4) resulted in MICs of one or two doubling dilutions lower than those obtained on agar with a neutral pH. A bioassay of the three agents incubated in air and in 5% carbon dioxide resulted in a significant loss of activity of all three agents in the carbon dioxide-enriched atmosphere. However, this loss-of-activity effect was significantly reduced when the bioassay medium was adjusted to pH 8.4 prior to incubation in 5% carbon dioxide. PMID:10428903

Elevated atmospheric carbon dioxide concentration affects interactions between Spodoptera exigua (Lepidoptera: Noctuidae) larvae and two host plant species outdoors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caulfield, F.; Bunce, J.A.

1994-08-01

Beet armyworm, Spodoptera exigua (Huebner), larvae were placed on sugarbeet (Beta vulgaris L.) and pigweed (Amaranthus hybridus L.) plants in outdoor chambers in which the plants were growing at either the ambient ([approximately] 350 [mu]l liter[sup [minus]1]) or ambient plus 350 [mu]l liter[sup [minus]1] ([approximately] 700 [mu]l liter[sup [minus]1]) carbon dioxide concentration. A series of experiments was performed to determine if larvae reduced plant growth differently at the two carbon dioxide concentrations in either species and if the insect growth or survival differed with carbon dioxide concentration. Leaf nitrogen, water, starch, and soluble carbohydrate contents were measured to assess carbonmore » dioxide concentration effects on leaf quality. Insect feeding significantly reduced plant growth in sugarbeet plants at 350 [mu]l liter[sup [minus]1] but not at 700 [mu]l liter[sup [minus]1] nor in pigweed at either carbon dioxide concentration. Larval survival was greater on sugarbeet plants at the elevated carbon dioxide concentration. Increased survival occurred only if the insects were at the elevated carbon dioxide concentration and consumed leaf material grown at the elevated concentration. Leaf quality was only marginally affected by growth at elevated carbon dioxide concentration in these experiments. The results indicate that in designing experiments to predict effects of elevated atmospheric carbon dioxide concentrations on plant-insect interactions, both plants and insects should be exposed to the experimental carbon dioxide concentrations, as well as to as realistic environmental conditions as possible.« less

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

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Carbon monoxide and carbon dioxide... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND... Test Procedures § 86.316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon...

A metal-free electrocatalyst for carbon dioxide reduction to multi-carbon hydrocarbons and oxygenates

PubMed Central

Wu, Jingjie; Ma, Sichao; Sun, Jing; Gold, Jake I.; Tiwary, ChandraSekhar; Kim, Byoungsu; Zhu, Lingyang; Chopra, Nitin; Odeh, Ihab N.; Vajtai, Robert; Yu, Aaron Z.; Luo, Raymond; Lou, Jun; Ding, Guqiao; Kenis, Paul J. A.; Ajayan, Pulickel M.

2016-01-01

Electroreduction of carbon dioxide into higher-energy liquid fuels and chemicals is a promising but challenging renewable energy conversion technology. Among the electrocatalysts screened so far for carbon dioxide reduction, which includes metals, alloys, organometallics, layered materials and carbon nanostructures, only copper exhibits selectivity towards formation of hydrocarbons and multi-carbon oxygenates at fairly high efficiencies, whereas most others favour production of carbon monoxide or formate. Here we report that nanometre-size N-doped graphene quantum dots (NGQDs) catalyse the electrochemical reduction of carbon dioxide into multi-carbon hydrocarbons and oxygenates at high Faradaic efficiencies, high current densities and low overpotentials. The NGQDs show a high total Faradaic efficiency of carbon dioxide reduction of up to 90%, with selectivity for ethylene and ethanol conversions reaching 45%. The C2 and C3 product distribution and production rate for NGQD-catalysed carbon dioxide reduction is comparable to those obtained with copper nanoparticle-based electrocatalysts. PMID:27958290

Sensitivity Studies for Space-based Measurement of Atmospheric Total Column Carbon Dioxide Using Reflected Sunlight

NASA Technical Reports Server (NTRS)

Mao, Jianping; Kawa, S. Randolph

2003-01-01

A series of sensitivity studies is carried out to explore the feasibility of space-based global carbon dioxide (CO2) measurements for global and regional carbon cycle studies. The detection method uses absorption of reflected sunlight in the CO2 vibration-rotation band at 1.58 microns. The sensitivities of the detected radiances are calculated using the line-by-line model (LBLRTM), implemented with the DISORT (Discrete Ordinates Radiative Transfer) model to include atmospheric scattering in this band. The results indicate that (a) the small (approx.1%) changes in CO2 near the Earth's surface are detectable in this CO2 band provided adequate sensor signal-to-noise ratio and spectral resolution are achievable; (b) the radiance signal or sensitivity to CO2 change near the surface is not significantly diminished even in the presence of aerosols and/or thin cirrus clouds in the atmosphere; (c) the modification of sunlight path length by scattering of aerosols and cirrus clouds could lead to large systematic errors in the retrieval; therefore, ancillary aerosol/cirrus cloud data are important to reduce retrieval errors; (d) CO2 retrieval requires good knowledge of the atmospheric temperature profile, e.g. approximately 1K RMS error in layer temperature; (e) the atmospheric path length, over which the CO2 absorption occurs, must be known in order to correctly interpret horizontal gradients of CO2 from the total column CO2 measurement; thus an additional sensor for surface pressure measurement needs to be attached for a complete measurement package.

A carbon dioxide stripping model for mammalian cell culture in manufacturing scale bioreactors.

PubMed

Xing, Zizhuo; Lewis, Amanda M; Borys, Michael C; Li, Zheng Jian

2017-06-01

Control of carbon dioxide within the optimum range is important in mammalian bioprocesses at the manufacturing scale in order to ensure robust cell growth, high protein yields, and consistent quality attributes. The majority of bioprocess development work is done in laboratory bioreactors, in which carbon dioxide levels are more easily controlled. Some challenges in carbon dioxide control can present themselves when cell culture processes are scaled up, because carbon dioxide accumulation is a common feature due to longer gas-residence time of mammalian cell culture in large scale bioreactors. A carbon dioxide stripping model can be used to better understand and optimize parameters that are critical to cell culture processes at the manufacturing scale. The prevailing carbon dioxide stripping models in literature depend on mass transfer coefficients and were applicable to cell culture processes with low cell density or at stationary/cell death phase. However, it was reported that gas bubbles are saturated with carbon dioxide before leaving the culture, which makes carbon dioxide stripping no longer depend on a mass transfer coefficient in the new generation cell culture processes characterized by longer exponential growth phase, higher peak viable cell densities, and higher specific production rate. Here, we present a new carbon dioxide stripping model for manufacturing scale bioreactors, which is independent of carbon dioxide mass transfer coefficient, but takes into account the gas-residence time and gas CO 2 saturation time. The model was verified by CHO cell culture processes with different peak viable cell densities (7 to 12 × 10 6  cells mL -1 ) for two products in 5,000-L and 25,000-L bioreactors. The model was also applied to a next generation cell culture process to optimize cell culture conditions and reduce carbon dioxide levels at manufacturing scale. The model provides a useful tool to understand and better control cell culture carbon dioxide profiles for process development, scale up, and characterization. Biotechnol. Bioeng. 2017;114: 1184-1194. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

High Temperature Raman Spectroscopy Study of the Conversion of Formate into Oxalate: Search for the Elusive CO 2 2 - Intermediate

NASA Astrophysics Data System (ADS)

Ryan, Charles; Mead, Anna; Lakkaraju, Prasad; Kaczur, Jerry; Bennett, Christopher; Dobbins, Tabbetha

Research on conversion of carbon dioxide into chemicals and fuels has the potential to address three problems of global relevance. (a) By removing carbon dioxide from the atmosphere, we are able to reduce the amount of greenhouse gases in the atmosphere, (b) by converting carbon dioxide into fuels, we are providing pathways for renewable energy sources, (c) by converting carbon dioxide into C2 and higher order compounds, and we are able to generate valuable precursors for organic synthesis. Formate salts are formed by the electrochemical reduction of carbon dioxide in aqueous media. However, in order to increase the utilization of carbon dioxide, methods need to be developed for the conversion of formate into compounds containing two carbon atoms such as oxalate or oxalic acid. Recently, we examined the thermal conversion of sodium formate into sodium oxalate utilizing a hydride ion catalyst. The proposed mechanism for this reaction involves the carbon dioxide dianion. Currently at NASA Goddard Space Flight Center.

The influence of deep-seabed CO2 sequestration on small metazoan (meiofaunal) viability and community structure: final technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thistle, D

2008-09-30

Since the industrial revolution, the burning of fossil fuel has produced carbon dioxide at an increasing rate. Present atmospheric concentration is about ~1.5 times the preindustrial level and is rising. Because carbon dioxide is a greenhouse gas, its increased concentration in the atmosphere is thought to be a cause of global warming. If so, the rate of global warming could be slowed if industrial carbon dioxide were not released into the atmosphere. One suggestion has been to sequester it in the deep ocean, but theory predicts that deep-sea species will be intolerant of the increased concentrations of carbon dioxide andmore » the increased acidity it would cause. The aim of our research was to test for consequences of carbon dioxide sequestration on deep-sea, sediment-dwelling meiofauna. Recent technical advances allowed us to test for effects in situ at depths proposed for sequestration. The basic experimental unit was an open-topped container into which we pumped ~20 L of liquid carbon dioxide. The liquid carbon dioxide mixed with near-bottom sea water, which produced carbon dioxide-rich sea water that flowed out over the near-by seabed. We did 30-day experiments at several locations and with different numbers of carbon dioxide-filled containers. Harpacticoid copepods (Crustacea) were our test taxon. In an experiment we did during a previous grant period, we found that large numbers of individuals exposed to carbon dioxide-rich sea water had been killed (Thistle et al. 2004). During the present grant period, we analyzed the species-level data in greater detail and discovered that, although individuals of many species had been killed by exposure to carbon dioxide-rich sea water, individuals of some species had not (Thistle et al. 2005). This result suggests that seabed sequestration of carbon dioxide will not just reduce the abundance of the meiofauna but will change the composition of the community. In another experiment, we found that some harpacticoid species swim away from an advancing front of carbon dioxide-rich sea water (Thistle et al. 2007). This result demonstrates a second way that deep-sea meiofauna react negatively to carbon dioxide-rich sea water. In summary, we used in situ experiments to show that carbon dioxide-rich sea water triggers an escape response in some harpacticoid species. It kills most individuals of most harpacticoid species that do not flee, but a few species seem to be unaffected. Proposals to reduce global warming by sequestering industrial carbon dioxide in the deep ocean should take note of these environmental consequences when pros and cons are weighed.« less

Novel Wireless Sensor System for Monitoring Oxygen, Temperature and Respiration Rate of Horticultural Crops Post Harvest

PubMed Central

Løkke, Mette Marie; Seefeldt, Helene Fast; Edwards, Gareth; Green, Ole

2011-01-01

In order to design optimal packages, it is of pivotal importance to determine the rate at which harvested fresh fruits and vegetables consume oxygen. The respiration rate of oxygen (RRO2) is determined by measuring the consumed oxygen per hour per kg plant material, and the rate is highly influenced by temperature and gas composition. Traditionally, RRO2 has been determined at discrete time intervals. In this study, wireless sensor networks (WSNs) were used to determine RRO2 continuously in plant material (fresh cut broccoli florets) at 5 °C, 10 °C and 20 °C and at modified gas compositions (decreasing oxygen and increasing carbon dioxide levels). Furthermore, the WSN enabled concomitant determination of oxygen and temperature in the very close vicinity of the plant material. This information proved a very close relationship between changes in temperature and respiration rate. The applied WSNs were unable to determine oxygen levels lower than 5% and carbon dioxide was not determined. Despite these drawbacks in relation to respiration analysis, the WSNs offer a new possibility to do continuous measurement of RRO2 in post harvest research, thereby investigating the close relation between temperature and RRO2. The conclusions are that WSNs have the potential to be used as a monitor of RRO2 of plant material after harvest, during storage and packaging, thereby leading to optimized consumer products. PMID:22164085

Stability Enhancement of Polymeric Sensing Films Using Fillers

NASA Technical Reports Server (NTRS)

Lin, Brian; Shevade, Abhijit; Ryan, Margaret Amy; Kisor, Adam; Yen, Shiao-Pin; Manatt, Kenneth; Homer, Margie; Fleurial, Jean-Pierre

2006-01-01

Experiments have shown the stability enhancement of polymeric sensing films on mixing the polymer with colloidal filler particles (submicron-sized) of carbon black, silver, titanium dioxide, and fumed silicon dioxide. The polymer films are candidates for potential use as sensing media in micro/nano chemical sensor devices. The need for stability enhancement of polymer sensing films arises because such films have been found to exhibit unpredictable changes in sensing activity over time, which could result in a possible failure of the sensor device. The changes in the physical properties of a polymer sensing film caused by the sorption of a target molecule can be measured by any of several established transduction techniques: electrochemical, optical, calorimetric, or piezoelectric, for example. The transduction technique used in the current polymer stability experiments is based on piezoelectric principles using a quartz-crystal microbalance (QCM). The surface of the QCM is coated with the polymer, and the mass uptake by the polymer film causes a change in the oscillating frequency of the quartz crystal. The polymer used for the current study is ethyl cellulose. The polymer/ polymer composite solutions were prepared in 1,3 dioxolane solvent. The filler concentration was fixed at 10 weight percent for the composites. The polymer or polymer composite solutions were cast on the quartz crystal having a fundamental frequency of about 6 MHz. The coated crystal was subjected to a multistage drying process to remove all measurable traces of the solvent. In each experiment, the frequency of oscillation was measured while the QCM was exposed to clean, dry, flowing air for about 30 minutes, then to air containing a known concentration of isopropanol for about 30 minutes, then again to clean dry air for about 30 minutes, and so forth. This cycle of measurements for varying isopropanol concentrations was repeated at intervals for several months. The figure depicts some of the sensing film stability results for ethyl cellulose polymer, ethyl cellulose-carbon black, and ethyl cellulose-silicon dioxide composite systems. An ethyl cellulose film exhibited a marked decline in response in the first few months of study and settled to a steady average response after about four months. However, response varied widely around the average response for ethyl cellulose film. In contrast, ethyl cellulose- carbon black and ethyl cellulose-silicon dioxide composites also declined in the early months, but showed more repeatable sensing film activity after the initial decline. Similar trends were observed in experiments for ethyl cellulose-titanium dioxide and ethyl cellulose-silver composites.

46 CFR 34.15-20 - Carbon dioxide storage-T/ALL.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Carbon dioxide storage-T/ALL. 34.15-20 Section 34.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS FIREFIGHTING EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 34.15-20 Carbon dioxide storage—T/ALL. (a) Except as provided in paragraph (b...

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

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Carbon dioxide alarm-T/ALL. 35.40-7 Section 35.40-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS OPERATIONS Posting and Marking Requirements-TB/ALL. § 35.40-7 Carbon dioxide alarm—T/ALL. Adjacent to all carbon dioxide fire extinguishing...

46 CFR 34.15-20 - Carbon dioxide storage-T/ALL.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Carbon dioxide storage-T/ALL. 34.15-20 Section 34.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS FIREFIGHTING EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 34.15-20 Carbon dioxide storage—T/ALL. (a) Except as provided in paragraph (b...

46 CFR 34.15-20 - Carbon dioxide storage-T/ALL.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Carbon dioxide storage-T/ALL. 34.15-20 Section 34.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS FIREFIGHTING EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 34.15-20 Carbon dioxide storage—T/ALL. (a) Except as provided in paragraph (b...

46 CFR 34.15-20 - Carbon dioxide storage-T/ALL.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Carbon dioxide storage-T/ALL. 34.15-20 Section 34.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS FIREFIGHTING EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 34.15-20 Carbon dioxide storage—T/ALL. (a) Except as provided in paragraph (b...

27 CFR 27.42a - Still wines containing carbon dioxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

.... Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine; except that a tolerance to this maximum limitation, not to exceed 0.009 gram of carbon dioxide per 100 milliliters of wine, will be allowed where the amount of carbon dioxide in excess of 0.392 gram per 100...

27 CFR 24.245 - Use of carbon dioxide in still wine.

Code of Federal Regulations, 2014 CFR

2014-04-01

... than 0.392 grams of carbon dioxide per 100 milliliters of wine. However, a tolerance of not more than 0.009 grams per 100 milliliters to the maximum limitation of carbon dioxide in still wine will be allowed where the amount of carbon dioxide in excess of 0.392 grams per 100 milliliters is due to...

27 CFR 27.42a - Still wines containing carbon dioxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

.... Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine; except that a tolerance to this maximum limitation, not to exceed 0.009 gram of carbon dioxide per 100 milliliters of wine, will be allowed where the amount of carbon dioxide in excess of 0.392 gram per 100...

27 CFR 27.42a - Still wines containing carbon dioxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

.... Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine; except that a tolerance to this maximum limitation, not to exceed 0.009 gram of carbon dioxide per 100 milliliters of wine, will be allowed where the amount of carbon dioxide in excess of 0.392 gram per 100...

27 CFR 27.42a - Still wines containing carbon dioxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

.... Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine; except that a tolerance to this maximum limitation, not to exceed 0.009 gram of carbon dioxide per 100 milliliters of wine, will be allowed where the amount of carbon dioxide in excess of 0.392 gram per 100...

27 CFR 27.42a - Still wines containing carbon dioxide.

Code of Federal Regulations, 2010 CFR

2010-04-01

.... Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine; except that a tolerance to this maximum limitation, not to exceed 0.009 gram of carbon dioxide per 100 milliliters of wine, will be allowed where the amount of carbon dioxide in excess of 0.392 gram per 100...

27 CFR 24.245 - Use of carbon dioxide in still wine.

Code of Federal Regulations, 2012 CFR

2012-04-01

... than 0.392 grams of carbon dioxide per 100 milliliters of wine. However, a tolerance of not more than 0.009 grams per 100 milliliters to the maximum limitation of carbon dioxide in still wine will be allowed where the amount of carbon dioxide in excess of 0.392 grams per 100 milliliters is due to...

21 CFR 201.161 - Carbon dioxide and certain other gases.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 4 2011-04-01 2011-04-01 false Carbon dioxide and certain other gases. 201.161 Section 201.161 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL LABELING Other Exemptions § 201.161 Carbon dioxide and certain other gases. (a) Carbon dioxide, cyclopropane, ethylene,...

46 CFR 108.627 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 108.627 Section 108.627 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide and clean agent alarms. Each carbon dioxide alarm must be...

46 CFR 169.732 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms. 169.732 Section 169.732 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide and clean agent alarms. (a) Each carbon dioxide o...

46 CFR 169.732 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 169.732 Section 169.732 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide and clean agent alarms. (a) Each carbon dioxide o...

46 CFR 108.627 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms. 108.627 Section 108.627 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide and clean agent alarms. Each carbon dioxide alarm must be...

46 CFR 97.37-9 - Carbon dioxide alarm.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN...

46 CFR 95.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a) Except as provided in paragraph (b) of this...

46 CFR 78.47-9 - Carbon dioxide alarm.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 3 2011-10-01 2011-10-01 false Carbon dioxide alarm. 78.47-9 Section 78.47-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM...

46 CFR 169.732 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 169.732 Section 169.732 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide and clean agent alarms. (a) Each carbon dioxide o...

46 CFR 95.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a) Except as provided in paragraph (b) of this...

21 CFR 201.161 - Carbon dioxide and certain other gases.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 4 2012-04-01 2012-04-01 false Carbon dioxide and certain other gases. 201.161 Section 201.161 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL LABELING Other Exemptions § 201.161 Carbon dioxide and certain other gases. (a) Carbon dioxide, cyclopropane, ethylene,...

46 CFR 131.815 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 131.815 Section 131.815 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.815 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire...

46 CFR 131.815 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms. 131.815 Section 131.815 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.815 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire...

46 CFR 131.815 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 131.815 Section 131.815 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.815 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire...

46 CFR 108.627 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 108.627 Section 108.627 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide and clean agent alarms. Each carbon dioxide alarm must be...

Carbon dioxide absorbent and method of using the same

DOEpatents

Perry, Robert James; O'Brien, Michael Joseph

2015-12-29

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

Carbon dioxide absorbent and method of using the same

DOEpatents

Perry, Robert James; O'Brien, Michael Joseph

2014-06-10

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

Carbon dioxide absorbent and method of using the same

DOEpatents

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

2011-10-04

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

Carbon sequestration in depleted oil shale deposits

DOEpatents

Burnham, Alan K; Carroll, Susan A

2014-12-02

A method and apparatus are described for sequestering carbon dioxide underground by mineralizing the carbon dioxide with coinjected fluids and minerals remaining from the extraction shale oil. In one embodiment, the oil shale of an illite-rich oil shale is heated to pyrolyze the shale underground, and carbon dioxide is provided to the remaining depleted oil shale while at an elevated temperature. Conditions are sufficient to mineralize the carbon dioxide.

Forecasting carbon dioxide emissions based on a hybrid of mixed data sampling regression model and back propagation neural network in the USA.

PubMed

Zhao, Xin; Han, Meng; Ding, Lili; Calin, Adrian Cantemir

2018-01-01

The accurate forecast of carbon dioxide emissions is critical for policy makers to take proper measures to establish a low carbon society. This paper discusses a hybrid of the mixed data sampling (MIDAS) regression model and BP (back propagation) neural network (MIDAS-BP model) to forecast carbon dioxide emissions. Such analysis uses mixed frequency data to study the effects of quarterly economic growth on annual carbon dioxide emissions. The forecasting ability of MIDAS-BP is remarkably better than MIDAS, ordinary least square (OLS), polynomial distributed lags (PDL), autoregressive distributed lags (ADL), and auto-regressive moving average (ARMA) models. The MIDAS-BP model is suitable for forecasting carbon dioxide emissions for both the short and longer term. This research is expected to influence the methodology for forecasting carbon dioxide emissions by improving the forecast accuracy. Empirical results show that economic growth has both negative and positive effects on carbon dioxide emissions that last 15 quarters. Carbon dioxide emissions are also affected by their own change within 3 years. Therefore, there is a need for policy makers to explore an alternative way to develop the economy, especially applying new energy policies to establish a low carbon society.

Carbon-14 analyses reveal fine structure of the urban carbon dioxide dome in the Salt Lake Valley, Utah, USA

NASA Astrophysics Data System (ADS)

Ehleringer, J. R.; Hopkins, F. M.; Xu, X.; Barnette, J.; Randerson, J. T.; Bush, S.; Lai, C.

2013-12-01

Carbon-14 analyses of mature deciduous tree leaves (aspen and cottonwood) were used to measure the increases in atmospheric carbon dioxide within the expansive urbanizing Salt Lake Valley, Utah, USA associated with fossil fuel combustion. Our objectives were twofold: to understand the fine scale spatial structure of elevated carbon dioxide levels in this urban environment and to relate these observations to actual carbon dioxide observations collected using both long-term monitoring sites and a mobile measurement vehicle. Paired observations of aspen and cottonwood at sites across the valley showed that there was no significant difference in carbon-14 values, allowing spatial pattern evaluations at sites where one but not the other species was present. Statistically significant patterns were observed over a two-year measurement period, with elevated carbon dioxide levels associated with carbon-14 depleted leaves, particularly in regions with higher vehicle travel. Carbon-14 content of leaves was significantly lower on 4-lane roads than on nearby 2-lane roads in both residential and commercial zones, consistent with atmospheric carbon dioxide observations. The analysis of spatial patterns in the carbon-14 in leaves was then used to evaluate how well these observations compared to instantaneous and long-term observations of carbon dioxide using traditional infrared gas analyzer approaches.

Fiber-Optic Ammonia Sensors

NASA Technical Reports Server (NTRS)

Carter, Michael T.

2003-01-01

Reversible, colorimetric fiber-optic sensors are undergoing development for use in measuring concentrations of ammonia in air at levels relevant to human health [0 to 50 parts per million (ppm)]. A sensor of this type includes an optical fiber that has been modified by replacing a portion of its cladding with a polymer coat that contains a dye that reacts reversibly with ammonia and changes color when it does so. The change in color is measured as a change in the amount of light transmitted from one end of the fiber to the other. Responses are reversible and proportional to the concentration of ammonia over the range from 9 to 175 ppm and in some cases the range of reversibility extends up to 270 ppm. The characteristic time for the response of a sensor to rise from 10 to 90 percent of full scale is about 25 seconds. These sensors are fully operational in pure carbon dioxide and are not adversely affected by humidity. This work was done by Michael T. Carter

A multi-sensor remote sensing approach for measuring primary production from space

NASA Technical Reports Server (NTRS)

Gautier, Catherine

1989-01-01

It is proposed to develop a multi-sensor remote sensing method for computing marine primary productivity from space, based on the capability to measure the primary ocean variables which regulate photosynthesis. The three variables and the sensors which measure them are: (1) downwelling photosynthetically available irradiance, measured by the VISSR sensor on the GOES satellite, (2) sea-surface temperature from AVHRR on NOAA series satellites, and (3) chlorophyll-like pigment concentration from the Nimbus-7/CZCS sensor. These and other measured variables would be combined within empirical or analytical models to compute primary productivity. With this proposed capability of mapping primary productivity on a regional scale, we could begin realizing a more precise and accurate global assessment of its magnitude and variability. Applications would include supplementation and expansion on the horizontal scale of ship-acquired biological data, which is more accurate and which supplies the vertical components of the field, monitoring oceanic response to increased atmospheric carbon dioxide levels, correlation with observed sedimentation patterns and processes, and fisheries management.

Fabrication of gas sensor based on field ionization from SWCNTs with tripolar microelectrode

NASA Astrophysics Data System (ADS)

Cai, Shengbing; Zhang, Yong; Duan, Zhemin

2012-12-01

We report the nanofabrication of a sulfur dioxide (SO2) sensor with a tripolar on-chip microelectrode utilizing a film of single-walled carbon nanotubes (SWCNTs) as the field ionization cathode, where the ion flow current and the partial discharge current generated by the field ionization process of gaseous molecules can be gauged to gas species and concentration. The variation of the sensitivity is less than 4% for all of the tested devices, and the sensor has selectivity against gases such as He, NO2, CO, H2, SO2 and O2. Further, the sensor response presents well-defined and reproducible linear behavior with regard to concentration in the range investigated and a detection limitation of <˜0.5 ppm for SO2. More importantly, a tripolar on-chip microelectrode with SWCNTs as a cathode exhibits an impressive performance with respect to stability and anti-oxidation behavior, which are significantly better than had been possible before in the traditional bipolar sensor under explicit circumstances at room temperature.

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

PubMed

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

2007-01-01

Exhaled nitric oxide (NO) is an important biomarker in asthma and other respiratory disorders. The optical performance of a NOCO(2) sensor employing integrated cavity output spectroscopy (ICOS) with a quantum cascade laser operating at 5.22 microm capable of real-time NO and CO(2) measurements in a single breath cycle is reported. A NO noise-equivalent concentration of 0.4 ppb within a 1-sec integration time is achieved. The off-axis ICOS sensor performance is compared to a chemiluminescent NO analyzer and a nondispersive infrared (NDIR) CO(2) absorption capnograph. Differences between the gas analyzers are assessed by the Bland-Altman method to estimate the expected variability between the gas sensors. The off-axis ICOS sensor measurements are in good agreement with the data acquired with the two commercial gas analyzers. This work demonstrates the performance characteristics and merits of mid-infrared spectroscopy for exhaled breath analysis.

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

DOEpatents

Aines, Roger D.; Bourcier, William L.

2014-08-19

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

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

DOEpatents

Aines, Roger D.; Bourcier, William L.

2010-11-09

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

A selective nanosensor device for exhaled breath analysis.

PubMed

Gouma, P; Prasad, A; Stanacevic, S

2011-09-01

This paper describes a novel concept of a three-nanosensor array microsystem that may potentially serve as a coarse diagnostic tool handheld breath analyzer to provide a first detection device. The specification and performance of a simple metal oxide nanosensor operating between three distinct temperatures are discussed, focusing on the need for a noninvasive blood cholesterol monitor. Interfacing the sensor array to an integrated circuit for electrical readout and temperature control provides a complete microsystem capable of capturing a single exhaled breath and analyzing it with respect to the relative content of isoprene, carbon dioxide and ammonia gas. This inexpensive sensor technology may be used as a personalized medical diagnostics tool in the near future.

Hydrodynamic Controls on Carbon Dioxide Efflux from Inland Waters

NASA Astrophysics Data System (ADS)

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

2013-12-01

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

Solubility of Carbon Dioxide in Water.

ERIC Educational Resources Information Center

Bush, Pat; And Others

1992-01-01

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

2006-07-08

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

Carbon dioxide emissions, GDP, energy use, and population growth: a multivariate and causality analysis for Ghana, 1971-2013.

PubMed

Asumadu-Sarkodie, Samuel; Owusu, Phebe Asantewaa

2016-07-01

In this study, the relationship between carbon dioxide emissions, GDP, energy use, and population growth in Ghana was investigated from 1971 to 2013 by comparing the vector error correction model (VECM) and the autoregressive distributed lag (ARDL). Prior to testing for Granger causality based on VECM, the study tested for unit roots, Johansen's multivariate co-integration and performed a variance decomposition analysis using Cholesky's technique. Evidence from the variance decomposition shows that 21 % of future shocks in carbon dioxide emissions are due to fluctuations in energy use, 8 % of future shocks are due to fluctuations in GDP, and 6 % of future shocks are due to fluctuations in population. There was evidence of bidirectional causality running from energy use to GDP and a unidirectional causality running from carbon dioxide emissions to energy use, carbon dioxide emissions to GDP, carbon dioxide emissions to population, and population to energy use. Evidence from the long-run elasticities shows that a 1 % increase in population in Ghana will increase carbon dioxide emissions by 1.72 %. There was evidence of short-run equilibrium relationship running from energy use to carbon dioxide emissions and GDP to carbon dioxide emissions. As a policy implication, the addition of renewable energy and clean energy technologies into Ghana's energy mix can help mitigate climate change and its impact in the future.

46 CFR 35.40-10 - Steam, foam, carbon dioxide, or clean agent fire smothering apparatus-TB/ALL.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Steam, foam, carbon dioxide, or clean agent fire... TANK VESSELS OPERATIONS Posting and Marking Requirements-TB/ALL § 35.40-10 Steam, foam, carbon dioxide, or clean agent fire smothering apparatus—TB/ALL. Each steam, foam, carbon dioxide, or clean agent...

46 CFR 35.40-10 - Steam, foam, carbon dioxide, or clean agent fire smothering apparatus-TB/ALL.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Steam, foam, carbon dioxide, or clean agent fire... TANK VESSELS OPERATIONS Posting and Marking Requirements-TB/ALL § 35.40-10 Steam, foam, carbon dioxide, or clean agent fire smothering apparatus—TB/ALL. Each steam, foam, carbon dioxide, or clean agent...

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

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 97.37-9 Section 97.37-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent...

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

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 3 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 78.47-9 Section 78.47-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire...

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

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 3 2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms. 78.47-9 Section 78.47-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire...

TES/Aura L2 Carbon Dioxide (CO2) Nadir V6 (TL2CO2N)

Atmospheric Science Data Center

2018-01-18

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 ... Contact User Services Parameters:  Carbon Dioxide Legacy:  Retired data product , click here ...

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

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 97.37-9 Section 97.37-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent...

46 CFR 34.15-20 - Carbon dioxide storage-T/ALL.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Carbon dioxide storage-T/ALL. 34.15-20 Section 34.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS FIREFIGHTING EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 34.15-20 Carbon dioxide storage—T/ALL. (a) Except as provided in paragraph (b) of this section, the cylinders...

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

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms. 97.37-9 Section 97.37-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent...

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

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 3 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 78.47-9 Section 78.47-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire...

TES/Aura L2 Carbon Dioxide (CO2) Nadir V6 (TL2CO2NS)

Atmospheric Science Data Center

2018-01-22

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 ... Contact ASDC User Services Parameters:  Carbon Dioxide Legacy:  Retired data product , click here ...

40 CFR 60.1745 - What must I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas?

Code of Federal Regulations, 2010 CFR

2010-07-01

... carbon dioxide instead of oxygen as a diluent gas? 60.1745 Section 60.1745 Protection of Environment... choose to monitor carbon dioxide instead of oxygen as a diluent gas? You must establish the relationship between oxygen and carbon dioxide during the initial evaluation of your continuous emission monitoring...

40 CFR 60.1745 - What must I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas?

Code of Federal Regulations, 2012 CFR

2012-07-01

... carbon dioxide instead of oxygen as a diluent gas? 60.1745 Section 60.1745 Protection of Environment... choose to monitor carbon dioxide instead of oxygen as a diluent gas? You must establish the relationship between oxygen and carbon dioxide during the initial evaluation of your continuous emission monitoring...

40 CFR 60.1745 - What must I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas?

Code of Federal Regulations, 2014 CFR

2014-07-01

... carbon dioxide instead of oxygen as a diluent gas? 60.1745 Section 60.1745 Protection of Environment... choose to monitor carbon dioxide instead of oxygen as a diluent gas? You must establish the relationship between oxygen and carbon dioxide during the initial evaluation of your continuous emission monitoring...

40 CFR 60.1745 - What must I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas?

Code of Federal Regulations, 2011 CFR

2011-07-01

... carbon dioxide instead of oxygen as a diluent gas? 60.1745 Section 60.1745 Protection of Environment... choose to monitor carbon dioxide instead of oxygen as a diluent gas? You must establish the relationship between oxygen and carbon dioxide during the initial evaluation of your continuous emission monitoring...

40 CFR 60.1745 - What must I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas?

Code of Federal Regulations, 2013 CFR

2013-07-01

... carbon dioxide instead of oxygen as a diluent gas? 60.1745 Section 60.1745 Protection of Environment... choose to monitor carbon dioxide instead of oxygen as a diluent gas? You must establish the relationship between oxygen and carbon dioxide during the initial evaluation of your continuous emission monitoring...

The carbon dioxide cycle

USGS Publications Warehouse

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

2005-01-01

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

The impact of energy, agriculture, macroeconomic and human-induced indicators on environmental pollution: evidence from Ghana.

PubMed

Asumadu-Sarkodie, Samuel; Owusu, Phebe Asantewaa

2017-03-01

In this study, the impact of energy, agriculture, macroeconomic and human-induced indicators on environmental pollution from 1971 to 2011 is investigated using the statistically inspired modification of partial least squares (SIMPLS) regression model. There was evidence of a linear relationship between energy, agriculture, macroeconomic and human-induced indicators and carbon dioxide emissions. Evidence from the SIMPLS regression shows that a 1% increase in crop production index will reduce carbon dioxide emissions by 0.71%. Economic growth increased by 1% will reduce carbon dioxide emissions by 0.46%, which means that an increase in Ghana's economic growth may lead to a reduction in environmental pollution. The increase in electricity production from hydroelectric sources by 1% will reduce carbon dioxide emissions by 0.30%; thus, increasing renewable energy sources in Ghana's energy portfolio will help mitigate carbon dioxide emissions. Increasing enteric emissions by 1% will increase carbon dioxide emissions by 4.22%, and a 1% increase in the nitrogen content of manure management will increase carbon dioxide emissions by 6.69%. The SIMPLS regression forecasting exhibited a 5% MAPE from the prediction of carbon dioxide emissions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waldhoff, Stephanie T.; Anthoff, David; Rose, Steven K.

We use FUND 3.8 to estimate the social cost of four greenhouse gases: carbon dioxide, methane, nitrous oxide, and sulphur hexafluoride emissions. The damage potential for each gas—the ratio of the social cost of the non-carbon dioxide greenhouse gas to the social cost of carbon dioxide—is also estimated. The damage potentials are compared to several metrics, focusing in particular on the global warming potentials, which are frequently used to measure the trade-off between gases in the form of carbon dioxide equivalents. We find that damage potentials could be significantly higher than global warming potentials. This finding implies that previous papersmore » have underestimated the relative importance of reducing non-carbon dioxide greenhouse gas emissions from an economic damage perspective. We show results for a range of sensitivity analyses: carbon dioxide fertilization on agriculture productivity, terrestrial feedbacks, climate sensitivity, discounting, equity weighting, and socioeconomic and emissions scenarios. The sensitivity of the results to carbon dioxide fertilization is a primary focus as it is an important element of climate change that has not been considered in much of the previous literature. We estimate that carbon dioxide fertilization has a large positive impact that reduces the social cost of carbon dioxide with a much smaller effect on the other greenhouse gases. As a result, our estimates of the damage potentials of methane and nitrous oxide are much higher compared to estimates that ignore carbon dioxide fertilization. As a result, our base estimates of the damage potential for methane and nitrous oxide that include carbon dioxide fertilization are twice their respective global warming potentials. Our base estimate of the damage potential of sulphur hexafluoride is similar to the one previous estimate, both almost three times the global warming potential.« less

Experimental measurement and thermodynamic modeling of the solubility of carbon dioxide in aqueous blends of monoethanolamine and diethanolamine

NASA Astrophysics Data System (ADS)

Suleman, Humbul; Maulud, Abdulhalim Shah; Man, Zakaria

2017-12-01

In this study, the solubilities of carbon dioxide in aqueous mixtures of monoethanolamine (MEA) and diethanolamine (DEA) were determined using a high pressure vapor-liquid equilibrium apparatus. The carbon dioxide loadings (mole of CO2/mole of amine mixture) were reported for a wide range of temperature (303.15, 323.15, 343.15 K) and pressure (100 - 4100 kPa). The carbon dioxide solubility shows an increase with increase in pressure and amine concentration and a decrease with increase in temperature in the aqueous blends of MEA and DEA. At carbon dioxide loadings above 1.0, the carbon dioxide solubility becomes a weak function of pressure and follows the general trend of carbon dioxide solubility in aqueous alkanolamines. The new experimental data points determined in this study were correlated by using a recently developed, enhanced Kent-Eisenberg model. An average absolute relative error of 9.4 % was observed between the model results and experimental data, indicating good correlative capability of the thermodynamic model.

Apparatus and method for removing solvent from carbon dioxide in resin recycling system

DOEpatents

Bohnert, George W [Harrisonville, MO; Hand, Thomas E [Lee's Summit, MO; DeLaurentiis, Gary M [Jamestown, CA

2009-01-06

A two-step resin recycling system and method solvent that produces essentially contaminant-free synthetic resin material. The system and method includes one or more solvent wash vessels to expose resin particles to a solvent, the solvent contacting the resin particles in the one or more solvent wash vessels to substantially remove contaminants on the resin particles. A separator is provided to separate the solvent from the resin particles after removal from the one or more solvent wash vessels. The resin particles are next exposed to carbon dioxide in a closed loop carbon dioxide system. The closed loop system includes a carbon dioxide vessel where the carbon dioxide is exposed to the resin, substantially removing any residual solvent remaining on the resin particles after separation. A separation vessel is also provided to separate the solvent from the solvent laden carbon dioxide. Both the carbon dioxide and the solvent are reused after separation in the separation vessel.

Epoxide-functionalization of polyethyleneimine for synthesis of stable carbon dioxide adsorbent in temperature swing adsorption

PubMed Central

Choi, Woosung; Min, Kyungmin; Kim, Chaehoon; Ko, Young Soo; Jeon, Jae Wan; Seo, Hwimin; Park, Yong-Ki; Choi, Minkee

2016-01-01

Amine-containing adsorbents have been extensively investigated for post-combustion carbon dioxide capture due to their ability to chemisorb low-concentration carbon dioxide from a wet flue gas. However, earlier studies have focused primarily on the carbon dioxide uptake of adsorbents, and have not demonstrated effective adsorbent regeneration and long-term stability under such conditions. Here, we report the versatile and scalable synthesis of a functionalized-polyethyleneimine (PEI)/silica adsorbent which simultaneously exhibits a large working capacity (2.2 mmol g−1) and long-term stability in a practical temperature swing adsorption process (regeneration under 100% carbon dioxide at 120 °C), enabling the separation of concentrated carbon dioxide. We demonstrate that the functionalization of PEI with 1,2-epoxybutane reduces the heat of adsorption and facilitates carbon dioxide desorption (>99%) during regeneration compared with unmodified PEI (76%). Moreover, the functionalization significantly improves long-term adsorbent stability over repeated temperature swing adsorption cycles due to the suppression of urea formation and oxidative amine degradation. PMID:27572662

The Impact of Carbon Dioxide on Climate.

ERIC Educational Resources Information Center

MacDonald, Gordon J.

1979-01-01

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

Fixation of carbon dioxide into dimethyl carbonate over titanium-based zeolitic thiophene-benzimidazolate framework

EPA Science Inventory

A titanium-based zeolitic thiophene-benzimidazolate framework has been designed for the direct synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide. The developed catalyst activates carbon dioxide and delivers over 16% yield of DMC without the use of any dehydra...

Self-Cleaning Boudouard Reactor for Full Oxygen Recovery from Carbon Dioxide

NASA Technical Reports Server (NTRS)

Coutts, Janelle; Hintze, Paul E.; Muscatello, Anthony C.; Gibson, Tracy L.; Captain, James G.; Lunn, Griffin M.; Devor, Robert W.; Bauer, Brint; Parks, Steve

2016-01-01

Oxygen recovery from respiratory carbon dioxide is an important aspect of human spaceflight. Methods exist to sequester the carbon dioxide, but production of oxygen needs further development. The current International Space Station Carbon Dioxide Reduction System (CRS) uses the Sabatier reaction to produce water (and ultimately breathing air). Oxygen recovery is limited to 50 because half of the hydrogen used in the Sabatier reactor is lost as methane, which is vented overboard. The Bosch reaction, which converts carbon dioxide to oxygen and solid carbon is capable of recovering all the oxygen from carbon dioxide, and is the only real alternative to the Sabatier reaction. However, the last reaction in the cycle, the Boudouard reaction, produces solid carbon and the resulting carbon buildup will eventually foul the nickel or iron catalyst, reducing reactor life and increasing consumables. To minimize this fouling and increase efficiency, a number of self-cleaning catalyst designs have been created. This paper will describe recent results evaluating one of the designs.

Self-Cleaning Boudouard Reactor for Full Oxygen Recovery from Carbon Dioxide

NASA Technical Reports Server (NTRS)

Hintze, Paul E.; Muscatello, Anthony C.; Meier, Anne J.; Gibson, Tracy L.; Captain, James G.; Lunn, Griffin M.; Devor, Robert W.

2016-01-01

Oxygen recovery from respiratory carbon dioxide is an important aspect of human spaceflight. Methods exist to sequester the carbon dioxide, but production of oxygen needs further development. The current International Space Station Carbon Dioxide Reduction System (CRS) uses the Sabatier reaction to produce water (and ultimately breathing air). Oxygen recovery is limited to 50% because half of the hydrogen used in the Sabatier reactor is lost as methane, which is vented overboard. The Bosch reaction, which converts carbon dioxide to oxygen and solid carbon is capable of recovering all the oxygen from carbon dioxide, and is the only real alternative to the Sabatier reaction. However, the last reaction in the cycle, the Boudouard reaction, produces solid carbon and the resulting carbon buildup will eventually foul the nickel or iron catalyst, reducing reactor life and increasing consumables. To minimize this fouling and increase efficiency, a number of self-cleaning catalyst designs have been created. This paper will describe recent results evaluating one of the designs.

Self-Cleaning Boudouard Reactor for Full Oxygen Recovery from Carbon Dioxide

NASA Technical Reports Server (NTRS)

Hintze, Paul E.; Muscatello, Anthony C.; Gibson, Tracy L.; Captain, James G.; Lunn, Griffin M.; Devor, Robert W.; Bauer, Brint; Parks, Steve

2016-01-01

Oxygen recovery from respiratory carbon dioxide is an important aspect of human spaceflight. Methods exist to sequester the carbon dioxide, but production of oxygen needs further development. The current International Space Station Carbon Dioxide Reduction System (CRS) uses the Sabatier reaction to produce water (and ultimately breathing air). Oxygen recovery is limited to 50% because half of the hydrogen used in the Sabatier reactor is lost as methane which is vented overboard. The Bosch reaction, which converts carbon dioxide to oxygen and solid carbon, is capable of recovering all the oxygen from carbon dioxide, and it is a promising alternative to the Sabatier reaction. However, the last reaction in the cycle, the Boudouard reaction, produces solid carbon, and the resulting carbon buildup eventually fouls the catalyst, reducing reactor life and increasing consumables. To minimize this fouling and increase efficiency, a number of self-cleaning catalyst designs have been created. This paper will describe recent results evaluating one of the designs.

Primary discussion of a carbon sink in the oceans

NASA Astrophysics Data System (ADS)

Ma, Caihua; You, Kui; Ji, Dechun; Ma, Weiwei; Li, Fengqi

2015-04-01

As a consequence of global warming and rising sea levels, the oceans are becoming a matter of concern for more and more people because these changes will impact the growth of living organisms as well as people's living standards. In particular, it is extremely important that the oceans absorb massive amounts of carbon dioxide. This paper takes a pragmatic approach to analyzing the oceans with respect to the causes of discontinuities in oceanic variables of carbon dioxide sinks. We report on an application of chemical, physical and biological methods to analyze the changes of carbon dioxide in oceans. Based on the relationships among the oceans, land, atmosphere and sediment with respect to carbon dioxide, the foundation of carbon dioxide in shell-building and ocean acidification, the changes in carbon dioxide in the oceans and their impact on climate change, and so on, a vital conclusion can be drawn from this study. Specifically, under the condition that the oceans are not disturbed by external forces, the oceans are a large carbon dioxide sink. The result can also be inferred by the formula: C=A-B and G=E+F when the marine ecosystem can keep a natural balance and the amount of carbon dioxide emission is limited within the carrying capacity of the oceans.

Scalar Similarity for Relaxed Eddy Accumulation Methods

NASA Astrophysics Data System (ADS)

Ruppert, Johannes; Thomas, Christoph; Foken, Thomas

2006-07-01

The relaxed eddy accumulation (REA) method allows the measurement of trace gas fluxes when no fast sensors are available for eddy covariance measurements. The flux parameterisation used in REA is based on the assumption of scalar similarity, i.e., similarity of the turbulent exchange of two scalar quantities. In this study changes in scalar similarity between carbon dioxide, sonic temperature and water vapour were assessed using scalar correlation coefficients and spectral analysis. The influence on REA measurements was assessed by simulation. The evaluation is based on observations over grassland, irrigated cotton plantation and spruce forest. Scalar similarity between carbon dioxide, sonic temperature and water vapour showed a distinct diurnal pattern and change within the day. Poor scalar similarity was found to be linked to dissimilarities in the energy contained in the low frequency part of the turbulent spectra ( < 0.01 Hz). The simulations of REA showed significant change in b-factors throughout the diurnal course. The b-factor is part of the REA parameterisation scheme and describes a relation between the concentration difference and the vertical flux of a trace gas. The diurnal course of b-factors for carbon dioxide, sonic temperature and water vapour matched well. Relative flux errors induced in REA by varying scalar similarity were generally below ± 10%. Systematic underestimation of the flux of up to - 40% was found for the use of REA applying a hyperbolic deadband (HREA). This underestimation was related to poor scalar similarity between the scalar of interest and the scalar used as proxy for the deadband definition.

Diurnal dynamics of oxygen and carbon dioxide concentrations in shoots and rhizomes of a perennial in a constructed wetland indicate down-regulation of below ground oxygen consumption

PubMed Central

Faußer, Anna C.; Dušek, Jiří; Čížková, Hana; Kazda, Marian

2016-01-01

Wetland plants actively provide oxygen for aerobic processes in submerged tissues and the rhizosphere. The novel concomitant assessment of diurnal dynamics of oxygen and carbon dioxide concentrations under field conditions tests the whole-system interactions in plant-internal gas exchange and regulation. Oxygen concentrations ([O2]) were monitored in-situ in central culm and rhizome pith cavities of common reed (Phragmites australis) using optical oxygen sensors. The corresponding carbon dioxide concentrations ([CO2]) were assessed via gas samples from the culms. Highly dynamic diurnal courses of [O2] were recorded, which started at 6.5–13 % in the morning, increased rapidly up to 22 % during midday and declined exponentially during the night. Internal [CO2] were high in the morning (1.55–17.5 %) and decreased (0.04–0.94 %) during the rapid increase of [O2] in the culms. The observed negative correlations between [O2] and [CO2] particularly describe the below ground relationship between plant-mediated oxygen supply and oxygen use by respiration and biogeochemical processes in the rhizosphere. Furthermore, the nocturnal declining slopes of [O2] in culms and rhizomes indicated a down-regulation of the demand for oxygen in the complete below ground plant-associated system. These findings emphasize the need for measurements of plant-internal gas exchange processes under field conditions because it considers the complex interactions in the oxic-anoxic interface. PMID:27207278

Development of an Electronic Kit for detecting asthma in Human Respiratory System

NASA Astrophysics Data System (ADS)

Shek Hong, Cheow; Ghani, Ahmad Shahrizan Abdul; Khairuddin, Ismail Mohd

2018-03-01

In this paper, a prototype of a carbon dioxide (CO2) measurement device is designed to detect and used to monitor asthma patients. Nowadays, capnogram device is widely used in monitoring asthma and asthma related medical services. However, capnogram is very costly and unaffordable for patient especially those who are in low income household. Thus, the proposed device is cost effective, affordable, and produced to detect and monitor the severity of asthma. Meanwhile, flow meter will cause patient to have chest pain as they needed maximum effort to blow in the device. To overcome these limitations, this prototype electronic kit is easy to use and suitable for all range patients. This prototype electronic kit consists of MH-Z14A carbon dioxide (CO2) sensor to detect the concentration of carbon dioxide from the user exhaled air. Arduino microcontroller is used to process the data while TFT Display shield is applied for data presentation. In addition, HC-06 Bluetooth module is used to communicate with PC for further analysis of the captured graph. This device was tested with 3 asthmatics and 3 normal users. The results showed that asthmatic user has a different graph pattern compared with normal user and these graphs are clearly differentiated on the device TFT screen. Asthmatic user produces “shark fin”-like pattern whereas normal user produces “square wave”-like pattern. This device has successfully produced distinguished-patterns difference between asthmatic and normal user; therefore, it is suitable for asthma monitoring.

A cloud detection scheme for the Chinese Carbon Dioxide Observation Satellite (TANSAT)

NASA Astrophysics Data System (ADS)

Wang, Xi; Guo, Zheng; Huang, Yipeng; Fan, Hongjie; Li, Wanbiao

2017-01-01

Cloud detection is an essential preprocessing step for retrieving carbon dioxide from satellite observations of reflected sunlight. During the pre-launch study of the Chinese Carbon Dioxide Observation Satellite (TANSAT), a cloud-screening scheme was presented for the Cloud and Aerosol Polarization Imager (CAPI), which only performs measurements in five channels located in the visible to near-infrared regions of the spectrum. The scheme for CAPI, based on previous cloudscreening algorithms, defines a method to regroup individual threshold tests for each pixel in a scene according to the derived clear confidence level. This scheme is proven to be more effective for sensors with few channels. The work relies upon the radiance data from the Visible and Infrared Radiometer (VIRR) onboard the Chinese FengYun-3A Polar-orbiting Meteorological Satellite (FY-3A), which uses four wavebands similar to that of CAPI and can serve as a proxy for its measurements. The scheme has been applied to a number of the VIRR scenes over four target areas (desert, snow, ocean, forest) for all seasons. To assess the screening results, comparisons against the cloud-screening product from MODIS are made. The evaluation suggests that the proposed scheme inherits the advantages of schemes described in previous publications and shows improved cloud-screening results. A seasonal analysis reveals that this scheme provides better performance during warmer seasons, except for observations over oceans, where results are much better in colder seasons.

Enhanced open ocean storage of CO2 from shelf sea pumping.

PubMed

Thomas, Helmuth; Bozec, Yann; Elkalay, Khalid; de Baar, Hein J W

2004-05-14

Seasonal field observations show that the North Sea, a Northern European shelf sea, is highly efficient in pumping carbon dioxide from the atmosphere to the North Atlantic Ocean. The bottom topography-controlled stratification separates production and respiration processes in the North Sea, causing a carbon dioxide increase in the subsurface layer that is ultimately exported to the North Atlantic Ocean. Globally extrapolated, the net uptake of carbon dioxide by coastal and marginal seas is about 20% of the world ocean's uptake of anthropogenic carbon dioxide, thus enhancing substantially the open ocean carbon dioxide storage.

A hybrid absorption–adsorption method to efficiently capture carbon

PubMed Central

Liu, Huang; Liu, Bei; Lin, Li-Chiang; Chen, Guangjin; Wu, Yuqing; Wang, Jin; Gao, Xueteng; Lv, Yining; Pan, Yong; Zhang, Xiaoxin; Zhang, Xianren; Yang, Lanying; Sun, Changyu; Smit, Berend; Wang, Wenchuan

2014-01-01

Removal of carbon dioxide is an essential step in many energy-related processes. Here we report a novel slurry concept that combines specific advantages of metal-organic frameworks, ion liquids, amines and membranes by suspending zeolitic imidazolate framework-8 in glycol-2-methylimidazole solution. We show that this approach may give a more efficient technology to capture carbon dioxide compared to conventional technologies. The carbon dioxide sorption capacity of our slurry reaches 1.25 mol l−1 at 1 bar and the selectivity of carbon dioxide/hydrogen, carbon dioxide/nitrogen and carbon dioxide/methane achieves 951, 394 and 144, respectively. We demonstrate that the slurry can efficiently remove carbon dioxide from gas mixtures at normal pressure/temperature through breakthrough experiments. Most importantly, the sorption enthalpy is only −29 kJ mol−1, indicating that significantly less energy is required for sorbent regeneration. In addition, from a technological point of view, unlike solid adsorbents slurries can flow and be pumped. This allows us to use a continuous separation process with heat integration. PMID:25296559

Fiber optic evanescent field sensor for detection of explosives and CO2 dissolved in water

NASA Astrophysics Data System (ADS)

Orghici, R.; Willer, U.; Gierszewska, M.; Waldvogel, S. R.; Schade, W.

2008-02-01

A fiber optic approach for the determination of the carbon dioxide concentration in the gas or fluid phase during sequestration, as well as for the sensing of the explosive TNT is described. The sensor consists of a quartz glass multimode fiber with core diameter of 200 μm and is based on the evanescent field principle. Cladding and jacket of the fiber are removed in the sensing portion, therefore interaction between light within the fiber and the surrounding medium is possible. A single-mode distributed feedback (DFB) laser diode with an emission wavelength around λ= 1.57 μm and a frequency doubled passively Q-switched Cr4+:Nd3+:YAG microchip laser (λ= 1064 nm)are used as light sources. The experimental setup and the sensitivity of the evanescent field sensor are characterized.

Detection and characterization of small hot fires: Comparing FireBird, BIRD, S-NPP VIIRS and MODIS capacities over gas flares

NASA Astrophysics Data System (ADS)

Ruecker, Gernot; Schroeder, Wilfrid; Lorenz, Eckehard; Kaiser, Johannes; Caseiro, Alexandre

2016-04-01

According to recent research, black carbon has the second strongest effect on the earth climate system after carbon dioxide. In high Northern latitudes, industrial gas flares are an important source of black carbon, especially in winter. This fact is particularly relevant for the relatively fast observed climate change in the Arctic since deposition of black carbon changes the albedo of snow and ice, thus leading to a positive feedback cycle. Here we explore gas flare detection and Fire Radiative Power (FRP) retrievals of the German FireBird TET-1 and BIRD Hotspot Recognition Systems (HSRS), the VIIRS sensor on board of the S-NPP satellite, and the MODIS sensor using temporally close to near coincident data acquisitions. Comparison is based on level 2 products developed for fire detection for the different sensors; in the case of S-NPP VIIRS we use two products: the new VIIRS 750m algorithm based on MODIS collection 6, and the 350 m algorithm based on the VIIRS mid-infrared I (Imaging) band, which offers high resolution, but no FRP retrievals. Results indicate that the highest resolution FireBird sensors offer the best detection capacities, though the level two product shows false alarms, followed by the VIIRS 350 m and 750 m algorithms. MODIS has the lowest detection rate. Preliminary results of FRP retrievals show that FireBird and VIIRS algorithms have a good agreement. Given the fact that most gas flaring is at the detection limit for medium to coarse resolution space borne sensors - and hence measurement errors may be high - our results indicates that a quantitative evaluation of gas flaring using these sensors is feasible. Results shall be used to develop a gas flare detection algorithm for Sentinel-3, and a similar methodology will be employed to validate the capacity of Sentinel 3 to detect and characterize small high temperature sources such as gas flares.

Using UAV's to Measure the Urban Boundary Layer

NASA Astrophysics Data System (ADS)

Jacob, R. L.; Sankaran, R.; Beckman, P. H.

2015-12-01

The urban boundary layer is one of the most poorly studied regions of the atmospheric boundary layer. Since a majority of the world's population now lives in urban areas, it is becoming a more important region to measure and model. The combination of relatively low-cost unmanned aerial vehicles and low-cost sensors can together provide a new instrument for measuring urban and other boundary layers. We have mounted a new sensor and compute platform called Waggle on an off-the-shelf XR8 octo-copter from 3DRobotics. Waggle consists of multiple sensors for measuring pressure, temperature and humidity as well as trace gases such as carbon monoxide, nitrogen dioxide, sulfur dioxide and ozone. A single board computer running Linux included in Waggle on the UAV allows in-situ processing and data storage. Communication of the data is through WiFi or 3G and the Waggle software can save the data in case communication is lost during flight. The flight pattern is a deliberately simple vertical ascent and descent over a fixed location to provide vertical profiles and so flights can be confined to urban parks, industrial areas or the footprint of a single rooftop. We will present results from test flights in urban and rural areas in and around Chicago.

Thermochemical cyclic system for splitting water and/or carbon dioxide by means of cerium compounds and reactions useful therein

DOEpatents

Bamberger, C.E.; Robinson, P.R.

A thermochemical cyclic process for producing hydrogen from water comprises reacting ceric oxide with monobasic or dibasic alkali metal phosphate to yield a solid reaction product, oxygen and water. The solid reaction product, alkali metal carbonate or bicarbonate, and water, are reacted to yield hydrogen, ceric oxide, carbon dioxide and trialkali metal phosphate. Ceric oxide is recycled. Trialkali metal phosphate, carbon dioxide and water are reacted to yield monobasic or dibasic alkali metal phosphate and alkali metal bicarbonate, which are recycled. The cyclic process can be modified for producing carbon monoxide from carbon dioxide by reacting the alkali metal cerous phosphate and alkali metal carbonate or bicarbonate in the absence of water to produce carbon monoxide, ceric oxide, carbon dioxide and trialkali metal phosphate. Carbon monoxide can be converted to hydrogen by the water gas shift reaction.

Thermochemical cyclic system for splitting water and/or carbon dioxide by means of cerium compounds and reactions useful therein

DOEpatents

Bamberger, Carlos E.; Robinson, Paul R.

1980-01-01

A thermochemical cyclic process for producing hydrogen from water comprises reacting ceric oxide with monobasic or dibasic alkali metal phosphate to yield a solid reaction product, oxygen and water. The solid reaction product, alkali metal carbonate or bicarbonate, and water, are reacted to yield hydrogen, ceric oxide, carbon dioxide and trialkali metal phosphate. Ceric oxide is recycled. Trialkali metal phosphate, carbon dioxide and water are reacted to yield monobasic or dibasic alkali metal phosphate and alkali metal bicarbonate, which are recycled. The cylic process can be modified for producing carbon monoxide from carbon dioxide by reacting the alkali metal cerous phosphate and alkali metal carbonate or bicarbonate in the absence of water to produce carbon monoxide, ceric oxide, carbon dioxide and trialkali metal phosphate. Carbon monoxide can be converted to hydrogen by the water gas shift reaction.

46 CFR 76.15-1 - Application.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Dioxide Extinguishing Systems, Details § 76.15-1 Application. (a) Where a carbon dioxide extinguishing... “high pressure system”, i.e., one in which the carbon dioxide is stored in liquid form at atmospheric temperature. Details for “low pressure systems”, i.e., those in which the carbon dioxide is stored in liquid...

46 CFR 76.15-1 - Application.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Dioxide Extinguishing Systems, Details § 76.15-1 Application. (a) Where a carbon dioxide extinguishing... “high pressure system”, i.e., one in which the carbon dioxide is stored in liquid form at atmospheric temperature. Details for “low pressure systems”, i.e., those in which the carbon dioxide is stored in liquid...

46 CFR 76.15-1 - Application.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Dioxide Extinguishing Systems, Details § 76.15-1 Application. (a) Where a carbon dioxide extinguishing... “high pressure system”, i.e., one in which the carbon dioxide is stored in liquid form at atmospheric temperature. Details for “low pressure systems”, i.e., those in which the carbon dioxide is stored in liquid...

46 CFR 76.15-1 - Application.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Dioxide Extinguishing Systems, Details § 76.15-1 Application. (a) Where a carbon dioxide extinguishing... “high pressure system”, i.e., one in which the carbon dioxide is stored in liquid form at atmospheric temperature. Details for “low pressure systems”, i.e., those in which the carbon dioxide is stored in liquid...

[Simplified identification and filter device of carbon dioxide].

PubMed

Mei, Xue-qin; Zhang, Yi-ping

2009-11-01

This paper presents the design and implementation ways of a simplified device to identify and filter carbon dioxide. The gas went through the test interface which had wet litmus paper before entering the abdominal cavity. Carbon dioxide dissolving in water turned acidic, making litmus paper change color to identify carbon dioxide, in order to avoid malpractice by connecting the wrong gas when making Endoscopic surgery.

46 CFR 35.40-7 - Carbon dioxide and clean agent alarms-T/ALL.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms-T/ALL. 35.40-7 Section 35.40-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS OPERATIONS Posting and Marking Requirements-TB/ALL § 35.40-7 Carbon dioxide and clean agent alarms—T/ALL. Each carbon dioxide or clean agent fire extinguishing alarm...

40 CFR 62.15200 - What must I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas?

Code of Federal Regulations, 2012 CFR

2012-07-01

... carbon dioxide instead of oxygen as a diluent gas? 62.15200 Section 62.15200 Protection of Environment... I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas? You must establish the relationship between oxygen and carbon dioxide during the initial evaluation of your continuous...

40 CFR 62.15200 - What must I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas?

Code of Federal Regulations, 2010 CFR

2010-07-01

... carbon dioxide instead of oxygen as a diluent gas? 62.15200 Section 62.15200 Protection of Environment... I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas? You must establish the relationship between oxygen and carbon dioxide during the initial evaluation of your continuous...

40 CFR 62.15200 - What must I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas?

Code of Federal Regulations, 2011 CFR

2011-07-01

... carbon dioxide instead of oxygen as a diluent gas? 62.15200 Section 62.15200 Protection of Environment... I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas? You must establish the relationship between oxygen and carbon dioxide during the initial evaluation of your continuous...

40 CFR 62.15200 - What must I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas?

Code of Federal Regulations, 2014 CFR

2014-07-01

... carbon dioxide instead of oxygen as a diluent gas? 62.15200 Section 62.15200 Protection of Environment... I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas? You must establish the relationship between oxygen and carbon dioxide during the initial evaluation of your continuous...

40 CFR 62.15200 - What must I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas?

Code of Federal Regulations, 2013 CFR

2013-07-01

... carbon dioxide instead of oxygen as a diluent gas? 62.15200 Section 62.15200 Protection of Environment... I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas? You must establish the relationship between oxygen and carbon dioxide during the initial evaluation of your continuous...

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

ERIC Educational Resources Information Center

Miyauchi, Takuya; Kamata, Masahiro

2012-01-01

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

Carbonic acid as a reserve of carbon dioxide on icy moons: The formation of carbon dioxide (CO{sub 2}) in a polar environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Brant M.; Kaiser, Ralf I.; Strazzulla, Giovanni, E-mail: brantmj@hawaii.edu

Carbon dioxide (CO{sub 2}) has been detected on the surface of several icy moons of Jupiter and Saturn via observation of the ν{sub 3} band with the Near-Infrared Mapping Spectrometer on board the Galileo spacecraft and the Visible-Infrared Mapping Spectrometer on board the Cassini spacecraft. Interestingly, the CO{sub 2} band for several of these moons exhibits a blueshift along with a broader profile than that seen in laboratory studies and other astrophysical environments. As such, numerous attempts have been made in order to clarify this abnormal behavior; however, it currently lacks an acceptable physical or chemical explanation. We present amore » rather surprising result pertaining to the synthesis of carbon dioxide in a polar environment. Here, carbonic acid was synthesized in a water (H{sub 2}O)-carbon dioxide (CO{sub 2}) (1:5) ice mixture exposed to ionizing radiation in the form of 5 keV electrons. The irradiated ice mixture was then annealed, producing pure carbonic acid which was then subsequently irradiated, recycling water and carbon dioxide. However, the observed carbon dioxide ν{sub 3} band matches almost exactly with that observed on Callisto; subsequent temperature program desorption studies reveal that carbon dioxide synthesized under these conditions remains in solid form until 160 K, i.e., the sublimation temperature of water. Consequently, our results suggest that carbon dioxide on Callisto as well as other icy moons is indeed complexed with water rationalizing the shift in peak frequency, broad profile, and the solid state existence on these relatively warm moons.« less

Fixation of carbon dioxide into dimethyl carbonate over ...

EPA Pesticide Factsheets

A titanium-based zeolitic thiophene-benzimidazolate framework has been designed for the direct synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide. The developed catalyst activates carbon dioxide and delivers over 16% yield of DMC without the use of any dehydrating agent or requirement for azeotropic distillation. Prepared for submission to Nature Scientific reports.

The Path of Carbon in Photosynthesis IX. Photosynthesis, Photoreduction, and the Hydrogen-Oxygen-Carbon Dioxide Dark Reaction

DOE R&D Accomplishments Database

Badin, E. J.; Calvin, M.

1950-02-01

A comparison of the rates of fixation of Carbon 14 dioxide in algae for the processes of photosynthesis, photoreduction and the hydrogen-oxygen-carbon dioxide dark reaction has been made. For the same series of experiments, rates of incorporation of tracer carbon into the separate soluble components using the radiogram method have been determined. The mechanism of carbon dioxide uptake has been shown to occur via two distinct paths. In all cases studied, essentially the same compounds appear radioactive. The distribution with time, however, differs markedly.

Potential New Sensor for Use With Conventional Gas Carburizing

NASA Technical Reports Server (NTRS)

deGroot, W. A.

1997-01-01

Diagnostics developed for in-situ monitoring of rocket combustion environments have been adapted for use in heat treating furnaces. Simultaneous, in-situ monitoring of the carbon monoxide, carbon dioxide, methane, water, nitrogen and hydrogen concentrations in the endothermic gas of a heat treating furnace has been demonstrated under a Space Act Agreement between NASA Lewis, the Heat Treating Network, and Akron Steel Treating Company. Equipment installed at the Akron Steel Treating Company showed the feasibility of the method. Clear and well-defined spectra of carbon monoxide, nitrogen and hydrogen were obtained by means of an optical probe mounted on the endothermic gas line of a gas generator inside the plant, with the data reduction hardware located in the basement laboratory. Signals to and from the probe were transmitted via optical fibers.

The Noninvasive Carbon Dioxide Gradient (NICO2G) during Hemorrhagic Shock

DTIC Science & Technology

2014-07-01

as well as a tPCO2- PaCO2 gap more than 16 mmHg were reported to be associated with poor outcomes in patients with septic shock (18). Previously, our...shortcomings, which include the need for frequent calibration with a tank of standardized cali- bration gas (24), relative bulk, need for a heated sensor, and...hemorrhagic, septic , and cardiogenic shock (27). Van der Linden et al. (28) demonstrated a venous-arterial gradient for PCO2 in hemorrhaged dogs. There was

Digital Architecture for a Trace Gas Sensor Platform

NASA Technical Reports Server (NTRS)

Gonzales, Paula; Casias, Miguel; Vakhtin, Andrei; Pilgrim, Jeffrey

2012-01-01

A digital architecture has been implemented for a trace gas sensor platform, as a companion to standard analog control electronics, which accommodates optical absorption whose fractional absorbance equivalent would result in excess error if assumed to be linear. In cases where the absorption (1-transmission) is not equivalent to the fractional absorbance within a few percent error, it is necessary to accommodate the actual measured absorption while reporting the measured concentration of a target analyte with reasonable accuracy. This requires incorporation of programmable intelligence into the sensor platform so that flexible interpretation of the acquired data may be accomplished. Several different digital component architectures were tested and implemented. Commercial off-the-shelf digital electronics including data acquisition cards (DAQs), complex programmable logic devices (CPLDs), field-programmable gate arrays (FPGAs), and microcontrollers have been used to achieve the desired outcome. The most completely integrated architecture achieved during the project used the CPLD along with a microcontroller. The CPLD provides the initial digital demodulation of the raw sensor signal, and then communicates over a parallel communications interface with a microcontroller. The microcontroller analyzes the digital signal from the CPLD, and applies a non-linear correction obtained through extensive data analysis at the various relevant EVA operating pressures. The microcontroller then presents the quantitatively accurate carbon dioxide partial pressure regardless of optical density. This technique could extend the linear dynamic range of typical absorption spectrometers, particularly those whose low end noise equivalent absorbance is below one-part-in-100,000. In the EVA application, it allows introduction of a path-length-enhancing architecture whose optical interference effects are well understood and quantified without sacrificing the dynamic range that allows quantitative detection at the higher carbon dioxide partial pressures. The digital components are compact and allow reasonably complete integration with separately developed analog control electronics without sacrificing size, mass, or power draw.

Nitrate dynamics within a stream-lake network through time and space

NASA Astrophysics Data System (ADS)

Loken, L. C.; Crawford, J. T.; Childress, E. S.; Casson, N. J.; Stanley, E. H.

2014-12-01

Nitrate dynamics in streams are governed by biology, hydrology, and geomorphology, and the ability to parse these drivers apart has improved with the development of accurate high-frequency sensors. By combining a stationary Eulerian and a quasi-Lagrangian sensor platform, we investigated the timing of nitrate flushing and identified locations of elevated biogeochemical cycling along a stream-lake network in Northern Wisconsin, USA. Two years of continuous oxygen, carbon dioxide, and discharge measurements were used to compute gross primary production (GPP) and ecosystem respiration (ER) downstream of a wetland reach of Allequash Creek. Metabolic rates and flow patterns were compared with nitrate concentrations measured every 30 minutes using an optical sensor. Additionally, we floated a sensor array from the headwater spring ponds through a heterogeneous stream reach consisting of wetlands, beaver ponds, forested segments, and two lakes. Two distinct temporal patterns of stream nitrate concentrations were observed. During high flow events such as spring snowmelt and summer rain events, nitrate concentrations increased from ~5 μM (baseflow) to 12 μM, suggesting flushing from catchment sources. During baseflow conditions, nitrate followed a diel cycle with a 0.3-1.0 μM daytime draw down. Daily nitrate reduction was positively correlated with GPP calculated from oxygen and carbon dioxide records. Lastly, spatial analyses revealed lowest nitrate concentrations in the wetland reach, approximately 2-3 μM lower than the upstream spring ponds, and downstream lakes and forested reaches. This snapshot implies greater nitrate removal potential in the wetland reach likely driven by denitrification in organic rich sediments and macrophyte uptake in the open canopy stream segment. Taken together the temporal and spatial results show the dynamics of hydrology, geomorphology, and biology to influence nitrate delivery and variability in ecosystem processing through a stream-lake system. Future ecosystem studies could benefit by including multiple reference frameworks to better assess processes not captured by a single station approach.

Seasonal analyses of carbon dioxide and energy fluxes above an oil palm plantation using the eddy covariance method

NASA Astrophysics Data System (ADS)

Ibrahim, Anis; Haniff Harun, Mohd; Yusup, Yusri

2017-04-01

A study presents the measurements of carbon dioxide and latent and sensible heat fluxes above a mature oil palm plantation on mineral soil in Keratong, Pahang, Peninsular Malaysia. The sampling campaign was conducted over an 25-month period, from September 2013 to February 2015 and May 2016 to November 2016, using the eddy covariance method. The main aim of this work is to assess carbon dioxide and energy fluxes over this plantation at different time scales, seasonal and diurnal, and determine the effects of season and relevant meteorological parameters on the latter fluxes. Energy balance closure analyses gave a slope between latent and sensible heat fluxes and total incoming energy to be 0.69 with an R2 value of 0.86 and energy balance ratio of 0.80. The averaged net radiation was 108 W m-2. The results show that at the diurnal scale, carbon dioxide, latent and sensible heat fluxes exhibited a clear diurnal trend where carbon dioxide flux was at its minimum - 3.59 μmol m-2 s-1 in the mid-afternoon and maximum in the morning while latent and sensible behaved conversely to the carbon dioxide flux. The average carbon dioxide flux was - 0.37 μmol m-2 s-1. At the seasonal timescale, carbon dioxide fluxes did not show any apparent trend except during the Northeast Monsoon where the highest variability of the monthly means of carbon dioxide occurred.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thurmond, Kyle; Loparo, Zachary; Partridge, Jr., William P.

Here, a sensor was developed for simultaneous measurements of carbon monoxide (CO) and carbon dioxide (CO 2) fluctuations in internal combustion engine exhaust gases. This sensor utilizes low-cost and compact light-emitting diodes (LEDs) that emit in the 3–5 µm wavelength range. An affordable, fast response sensor that can measure these gases has a broad application that can lead to more efficient, fuel-flexible engines and regulation of harmful emissions. Light emission from LEDs is spectrally broader and more spatially divergent when compared to that of lasers, which presented many design challenges. Optical design studies addressed some of the non-ideal characteristics ofmore » the LED emissions. Measurements of CO and CO 2 were conducted using their fundamental absorption bands centered at 4.7 µm and 4.3 µm, respectively, while a 3.6 µm reference LED was used to account for scattering losses (due to soot, window deposits, etc.) common to the three measurement LEDs. Instrument validation and calibration was performed using a laboratory flow cell and bottled-gas mixtures. The sensor was able to detect CO 2 and CO concentration changes as small as 30 ppm and 400 ppm, respectively. Because of the many control and monitor species with infra-red absorption features, which can be measured using the strategy described, this work demonstrates proof of concept for a wider range of fast (250 Hz) and low-cost sensors for gas measurement and process monitoring.« less

Development and Measurements of a Mid-Infrared Multi-Gas Sensor System for CO, CO2 and CH4 Detection

PubMed Central

Dong, Ming; Zheng, Chuantao; Miao, Shuzhuo; Zhang, Yu; Du, Qiaoling; Wang, Yiding

2017-01-01

A multi-gas sensor system was developed that uses a single broadband light source and multiple carbon monoxide (CO), carbon dioxide (CO2) and methane (CH4) pyroelectric detectors by use of the time division multiplexing (TDM) technique. A stepper motor-based rotating system and a single-reflection spherical optical mirror were designed and adopted to realize and enhance multi-gas detection. Detailed measurements under static detection mode (without rotation) and dynamic mode (with rotation) were performed to study the performance of the sensor system for the three gas species. Effects of the motor rotating period on sensor performances were also investigated and a rotation speed of 0.4π rad/s was required to obtain a stable sensing performance, corresponding to a detection period of ~10 s to realize one round of detection. Based on an Allan deviation analysis, the 1σ detection limits under static operation are 2.96, 4.54 and 2.84 parts per million in volume (ppmv) for CO, CO2 and CH4, respectively and the 1σ detection limits under dynamic operations are 8.83, 8.69 and 10.29 ppmv for the three gas species, respectively. The reported sensor has potential applications in various fields requiring CO, CO2 and CH4 detection such as in coal mines. PMID:28953260

The effects of two thick film deposition methods on tin dioxide gas sensor performance.

PubMed

Bakrania, Smitesh D; Wooldridge, Margaret S

2009-01-01

This work demonstrates the variability in performance between SnO(2) thick film gas sensors prepared using two types of film deposition methods. SnO(2) powders were deposited on sensor platforms with and without the use of binders. Three commonly utilized binder recipes were investigated, and a new binder-less deposition procedure was developed and characterized. The binder recipes yielded sensors with poor film uniformity and poor structural integrity, compared to the binder-less deposition method. Sensor performance at a fixed operating temperature of 330 °C for the different film deposition methods was evaluated by exposure to 500 ppm of the target gas carbon monoxide. A consequence of the poor film structure, large variability and poor signal properties were observed with the sensors fabricated using binders. Specifically, the sensors created using the binder recipes yielded sensor responses that varied widely (e.g., S = 5 - 20), often with hysteresis in the sensor signal. Repeatable and high quality performance was observed for the sensors prepared using the binder-less dispersion-drop method with good sensor response upon exposure to 500 ppm CO (S = 4.0) at an operating temperature of 330 °C, low standard deviation to the sensor response (±0.35) and no signal hysteresis.

The Effects of Two Thick Film Deposition Methods on Tin Dioxide Gas Sensor Performance

PubMed Central

Bakrania, Smitesh D.; Wooldridge, Margaret S.

2009-01-01

This work demonstrates the variability in performance between SnO2 thick film gas sensors prepared using two types of film deposition methods. SnO2 powders were deposited on sensor platforms with and without the use of binders. Three commonly utilized binder recipes were investigated, and a new binder-less deposition procedure was developed and characterized. The binder recipes yielded sensors with poor film uniformity and poor structural integrity, compared to the binder-less deposition method. Sensor performance at a fixed operating temperature of 330 °C for the different film deposition methods was evaluated by exposure to 500 ppm of the target gas carbon monoxide. A consequence of the poor film structure, large variability and poor signal properties were observed with the sensors fabricated using binders. Specifically, the sensors created using the binder recipes yielded sensor responses that varied widely (e.g., S = 5 – 20), often with hysteresis in the sensor signal. Repeatable and high quality performance was observed for the sensors prepared using the binder-less dispersion-drop method with good sensor response upon exposure to 500 ppm CO (S = 4.0) at an operating temperature of 330 °C, low standard deviation to the sensor response (±0.35) and no signal hysteresis. PMID:22399977

Cerebral blood flow response to changes in arterial carbon dioxide tension during hypothermic cardiopulmonary bypass in children

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kern, F.H.; Ungerleider, R.M.; Quill, T.J.

1991-04-01

We examined the relationship of changes in partial pressure of carbon dioxide on cerebral blood flow responsiveness in 20 pediatric patients undergoing hypothermic cardiopulmonary bypass. Cerebral blood flow was measured during steady-state hypothermic cardiopulmonary bypass with the use of xenon 133 clearance methodology at two different arterial carbon dioxide tensions. During these measurements there was no significant change in mean arterial pressure, nasopharyngeal temperature, pump flow rate, or hematocrit value. Cerebral blood flow was found to be significantly greater at higher arterial carbon dioxide tensions (p less than 0.01), so that for every millimeter of mercury rise in arterial carbonmore » dioxide tension there was a 1.2 ml.100 gm-1.min-1 increase in cerebral blood flow. Two factors, deep hypothermia (18 degrees to 22 degrees C) and reduced age (less than 1 year), diminished the effect carbon dioxide had on cerebral blood flow responsiveness but did not eliminate it. We conclude that cerebral blood flow remains responsive to changes in arterial carbon dioxide tension during hypothermic cardiopulmonary bypass in infants and children; that is, increasing arterial carbon dioxide tension will independently increase cerebral blood flow.« less

Production of magnesium metal

DOEpatents

Blencoe, James G [Harriman, TN; Anovitz, Lawrence M [Knoxville, TN; Palmer, Donald A [Oliver Springs, TN; Beard, James S [Martinsville, VA

2010-02-23

A process of producing magnesium metal includes providing magnesium carbonate, and reacting the magnesium carbonate to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The carbon dioxide is used as a reactant in a second process. In another embodiment of the process, a magnesium silicate is reacted with a caustic material to produce magnesium hydroxide. The magnesium hydroxide is reacted with a source of carbon dioxide to produce magnesium carbonate. The magnesium carbonate is reacted to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The invention further relates to a process for production of magnesium metal or a magnesium compound where an external source of carbon dioxide is not used in any of the reactions of the process. The invention also relates to the magnesium metal produced by the processes described herein.

Revisiting the emissions-energy-trade nexus: evidence from the newly industrializing countries.

PubMed

Ahmed, Khalid; Shahbaz, Muhammad; Kyophilavong, Phouphet

2016-04-01

This paper applies Pedroni's panel cointegration approach to explore the causal relationship between trade openness, carbon dioxide emissions, energy consumption, and economic growth for the panel of newly industrialized economies (i.e., Brazil, India, China, and South Africa) over the period of 1970-2013. Our panel cointegration estimation results found majority of the variables cointegrated and confirm the long-run association among the variables. The Granger causality test indicates bidirectional causality between carbon dioxide emissions and energy consumption. A unidirectional causality is found running from trade openness to carbon dioxide emission and energy consumption and economic growth to carbon dioxide emissions. The results of causality analysis suggest that the trade liberalization in newly industrialized economies induces higher energy consumption and carbon dioxide emissions. Furthermore, the causality results are checked using an innovative accounting approach which includes forecast-error variance decomposition test and impulse response function. The long-run coefficients are estimated using fully modified ordinary least square (FMOLS) method, and results conclude that the trade openness and economic growth reduce carbon dioxide emissions in the long run. The results of FMOLS test sound the existence of environmental Kuznets curve hypothesis. It means that trade liberalization induces carbon dioxide emission with increased national output, but it offsets that impact in the long run with reduced level of carbon dioxide emissions.

Carbon dioxide stripping in aquaculture -- part II: development of gas transfer models

USGS Publications Warehouse

Colt, John; Watten, Barnaby; Pfeiffer, Tim

2012-01-01

The basic mass transfer equation for gases such as oxygen and carbon dioxide can be derived from integration of the driving force equation. Because of the physical characteristics of the gas transfer processes, slightly different models are used for aerators tested under the non steady-state procedures, than for packed columns, or weirs. It is suggested that the standard condition for carbon dioxide should be 20 °C, 1 atm, CCO2=20 mg/kg, and XCO2=0.000285. The selection of the standard condition for carbon dioxide based on a fixed mole fraction ensures that standardized carbon dioxide transfer rates will be comparable even though the value of C*CO2 in the atmosphere is increasing with time. The computation of mass transfer for carbon dioxide is complicated by the impact of water depth and gas phase enrichment on the saturation concentration within the unit, although the importance of either factor depends strongly on the specific type of aerator. For some types of aerators, the most accurate gas phase model remains to be determined for carbon dioxide. The assumption that carbon dioxide can be treated as a non-reactive gas in packed columns may apply for cold acidic waters but not for warm alkaline waters.

Optical Multi-Gas Monitor Technology Demonstration on the International Space Station

NASA Technical Reports Server (NTRS)

Pilgrim, Jeffrey S.; Wood, William R.; Casias, Miguel E.; Vakhtin, Andrei B.; Johnson, Michael D.; Mudgett, Paul D.

2014-01-01

The International Space Station (ISS) employs a suite of portable and permanently located gas monitors to insure crew health and safety. These sensors are tasked with functions ranging from fixed mass spectrometer based major constituents analysis to portable electrochemical sensor based combustion product monitoring. An all optical multigas sensor is being developed that can provide the specificity of a mass spectrometer with the portability of an electrochemical cell. The technology, developed under the Small Business Innovation Research program, allows for an architecture that is rugged, compact and low power. A four gas version called the Multi-Gas Monitor was launched to ISS in November 2013 aboard Soyuz and activated in February 2014. The portable instrument is comprised of a major constituents analyzer (water vapor, carbon dioxide, oxygen) and high dynamic range real-time ammonia sensor. All species are sensed inside the same enhanced path length optical cell with a separate vertical cavity surface emitting laser (VCSEL) targeted at each species. The prototype is controlled digitally with a field-programmable gate array/microcontroller architecture. The optical and electronic approaches are designed for scalability and future versions could add three important acid gases and carbon monoxide combustion product gases to the four species already sensed. Results obtained to date from the technology demonstration on ISS are presented and discussed.

Autonomous Observational Platforms for Ocean Studies: Operation, Advantages of Sensor Technology and Data Management

NASA Astrophysics Data System (ADS)

Atamanchuk, D.; Lai, J.; Vining, M.; Kehoe, D.; Siddall, G.; Send, U.; Wallace, D.

2016-02-01

Ocean Science and Technology research group (CERC.OCEAN) at Dalhousie University focuses on new approaches in design and development of autonomous platforms to study biogeochemical and ecological changes in the world's oceans. The principal research regions included the Labrador Sea, the Northwest Atlantic between Halifax and Bermuda, and the coastal areas of Atlantic Canada. The need for improved constraints on the ocean's present and future carbon cycle is of high relevance for the Northwest Atlantic, which is recognized as a largest sink of carbon dioxide(CO2) through air-sea exchange and subsequent transport to deeper layers of the global ocean. With the use of novel sensor technology integrated into the designed platforms we are achieving a superior spatial and temporal resolution of observations. SeaCycler - a surface piercing mooring - was designed to endure year-long measurements in harsh conditions of the open ocean, like Labrador Sea, while making daily profiles of the upper 150m of the water column. Significant research efforts within CERC.OCEAN are dedicated for improving sensors' data outcome. This includes testing, calibration of the sensors, QC and postprocessing to assure reliable and trustworthy measurements. Examples and implication of the data from SeaCycler, and other platforms including buoys, and automonous Volunteer Observing Ship (VOS) flow-through system will be presented.

Environment and Materials Stewardship | NREL

Science.gov Websites

dioxide equivalent of natural gas in heating facilities and experiments; 105metric tons of carbon dioxide equivalent in fleet and equipment; 15 metric tons of carbon dioxide equivalent in fluorinated gases and refrigerants; and 10 metric tons of carbon dioxide equivalent in dry ice use in laboratories. Scope 2 accounts

40 CFR 62.15175 - What continuous emission monitoring systems must I install for gaseous pollutants?

Code of Federal Regulations, 2010 CFR

2010-07-01

..., maintain, and operate continuous emission monitoring systems for oxygen (or carbon dioxide), sulfur dioxide, and carbon monoxide. If you operate a Class I municipal waste combustion unit, also install, calibrate... emission monitoring system for sulfur dioxide, nitrogen oxides, and oxygen (or carbon dioxide) at the...

40 CFR 60.1720 - What continuous emission monitoring systems must I install for gaseous pollutants?

Code of Federal Regulations, 2011 CFR

2011-07-01

..., maintain, and operate continuous emission monitoring systems for oxygen (or carbon dioxide), sulfur dioxide, and carbon monoxide. If you operate a Class I municipal waste combustion unit, also install, calibrate... emission monitoring systems for sulfur dioxide, nitrogen oxides, and oxygen (or carbon dioxide) at the...

40 CFR 60.1720 - What continuous emission monitoring systems must I install for gaseous pollutants?

Code of Federal Regulations, 2010 CFR

2010-07-01

..., maintain, and operate continuous emission monitoring systems for oxygen (or carbon dioxide), sulfur dioxide, and carbon monoxide. If you operate a Class I municipal waste combustion unit, also install, calibrate... emission monitoring systems for sulfur dioxide, nitrogen oxides, and oxygen (or carbon dioxide) at the...

40 CFR 62.15175 - What continuous emission monitoring systems must I install for gaseous pollutants?

Code of Federal Regulations, 2011 CFR

2011-07-01

..., maintain, and operate continuous emission monitoring systems for oxygen (or carbon dioxide), sulfur dioxide, and carbon monoxide. If you operate a Class I municipal waste combustion unit, also install, calibrate... emission monitoring system for sulfur dioxide, nitrogen oxides, and oxygen (or carbon dioxide) at the...

Selective free radical reactions using supercritical carbon dioxide.

PubMed

Cormier, Philip J; Clarke, Ryan M; McFadden, Ryan M L; Ghandi, Khashayar

2014-02-12

We report herein a means to modify the reactivity of alkenes, and particularly to modify their selectivity toward reactions with nonpolar reactants (e.g., nonpolar free radicals) in supercritical carbon dioxide near the critical point. Rate constants for free radical addition of the light hydrogen isotope muonium to ethylene, vinylidene fluoride, and vinylidene chloride in supercritical carbon dioxide are compared over a range of pressures and temperatures. Near carbon dioxide's critical point, the addition to ethylene exhibits critical speeding up, while the halogenated analogues display critical slowing. This suggests that supercritical carbon dioxide as a solvent may be used to tune alkene chemistry in near-critical conditions.

40 CFR 91.320 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... monthly thereafter, or within one month prior to the certification test, calibrate the NDIR carbon dioxide... the analyzer to optimize performance. (2) Zero the carbon dioxide analyzer with either purified synthetic air or zero-grade nitrogen. (3) Calibrate on each normally used operating range with carbon...

An Electrochemical NO2 Sensor Based on Ionic Liquid: Influence of the Morphology of the Polymer Electrolyte on Sensor Sensitivity

PubMed Central

Kuberský, Petr; Altšmíd, Jakub; Hamáček, Aleš; Nešpůrek, Stanislav; Zmeškal, Oldřich

2015-01-01

A systematic study was carried out to investigate the effect of ionic liquid in solid polymer electrolyte (SPE) and its layer morphology on the characteristics of an electrochemical amperometric nitrogen dioxide sensor. Five different ionic liquids were immobilized into a solid polymer electrolyte and key sensor parameters (sensitivity, response/recovery times, hysteresis and limit of detection) were characterized. The study revealed that the sensor based on 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][N(Tf)2]) showed the best sensitivity, fast response/recovery times, and low sensor response hysteresis. The working electrode, deposited from water-based carbon nanotube ink, was prepared by aerosol-jet printing technology. It was observed that the thermal treatment and crystallinity of poly(vinylidene fluoride) (PVDF) in the solid polymer electrolyte influenced the sensitivity. Picture analysis of the morphology of the SPE layer based on [EMIM][N(Tf)2] ionic liquid treated under different conditions suggests that the sensor sensitivity strongly depends on the fractal dimension of PVDF spherical objects in SPE. Their deformation, e.g., due to crowding, leads to a decrease in sensor sensitivity. PMID:26569248

Use of multiple sensor technologies for quality control of in situ biogeochemical measurements: A SeaCycler case study

NASA Astrophysics Data System (ADS)

Atamanchuk, Dariia; Koelling, Jannes; Lai, Jeremy; Send, Uwe; Wallace, Douglas

2017-04-01

Over the last two decades observing capacity for the global ocean has increased dramatically. Emerging sensor technologies for dissolved gases, nutrients and bio-optical properties in seawater are allowing extension of in situ observations beyond the traditionally measured salinity, temperature and pressure (CTD). However the effort to extend observations using autonomous instruments and platforms carries the risk of losing the level of data quality achievable through conventional water sampling techniques. We will present results from a case study with the SeaCycler profiling winch focusing on quality control of the in-situ measurements. A total of 13 sensors were deployed from May 2016 to early 2017 on SeaCycler's profiling sensor float, including CTD, dissolved oxygen (O2, 3 sensors), carbon dioxide (pCO2, 2 sensors), nutrients, velocity sensors, fluorometer, transmissometer, single channel PAR sensor, and others. We will highlight how multiple measurement technologies (e.g. for O2 and CO2) complement each other and result in a high quality data product. We will also present an initial assessment of the bio-optical data, their implications for seasonal phytoplankton dynamics and comparisons to climatologies and ocean-color data products obtained from the MODIS satellite.

Tuneable diode laser gas analyser for methane measurements on a large scale solid oxide fuel cell

NASA Astrophysics Data System (ADS)

Lengden, Michael; Cunningham, Robert; Johnstone, Walter

2011-10-01

A new in-line, real time gas analyser is described that uses tuneable diode laser spectroscopy (TDLS) for the measurement of methane in solid oxide fuel cells. The sensor has been tested on an operating solid oxide fuel cell (SOFC) in order to prove the fast response and accuracy of the technology as compared to a gas chromatograph. The advantages of using a TDLS system for process control in a large-scale, distributed power SOFC unit are described. In future work, the addition of new laser sources and wavelength modulation will allow the simultaneous measurement of methane, water vapour, carbon-dioxide and carbon-monoxide concentrations.

A zirconium dioxide ammonia microsensor integrated with a readout circuit manufactured using the 0.18 μm CMOS process.

PubMed

Lin, Guan-Ming; Dai, Ching-Liang; Yang, Ming-Zhi

2013-03-15

The study presents an ammonia microsensor integrated with a readout circuit on-a-chip fabricated using the commercial 0.18 μm complementary metal oxide semiconductor (CMOS) process. The integrated sensor chip consists of a heater, an ammonia sensor and a readout circuit. The ammonia sensor is constructed by a sensitive film and the interdigitated electrodes. The sensitive film is zirconium dioxide that is coated on the interdigitated electrodes. The heater is used to provide a working temperature to the sensitive film. A post-process is employed to remove the sacrificial layer and to coat zirconium dioxide on the sensor. When the sensitive film adsorbs or desorbs ammonia gas, the sensor produces a change in resistance. The readout circuit converts the resistance variation of the sensor into the output voltage. The experiments show that the integrated ammonia sensor has a sensitivity of 4.1 mV/ppm.

Carbon dioxide capture process with regenerable sorbents

DOEpatents

Pennline, Henry W.; Hoffman, James S.

2002-05-14

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

Development of a prototype regenerable carbon dioxide absorber

NASA Technical Reports Server (NTRS)

Onischak, M.

1976-01-01

Design information was obtained for a new, regenerable carbon dioxide control system for extravehicular activity life support systems. Solid potassium carbonate was supported in a thin porous sheet form and fabricated into carbon dioxide absorber units. Carbon dioxide and water in the life support system atmosphere react with the potassium carbonate and form potassium bicarbonate. The bicarbonate easily reverts to the carbonate by heating to 150 deg C. The methods of effectively packing the sorbent material into EVA-sized units and the effects of inlet concentrations, flowrate, and temperature upon performance were investigated. The cycle life of the sorbent upon the repeated thermal regenerations was demonstrated through 90 cycles.

Physiological sensor signals classification for healthcare using sensor data fusion and case-based reasoning.

PubMed

Begum, Shahina; Barua, Shaibal; Ahmed, Mobyen Uddin

2014-07-03

Today, clinicians often do diagnosis and classification of diseases based on information collected from several physiological sensor signals. However, sensor signal could easily be vulnerable to uncertain noises or interferences and due to large individual variations sensitivity to different physiological sensors could also vary. Therefore, multiple sensor signal fusion is valuable to provide more robust and reliable decision. This paper demonstrates a physiological sensor signal classification approach using sensor signal fusion and case-based reasoning. The proposed approach has been evaluated to classify Stressed or Relaxed individuals using sensor data fusion. Physiological sensor signals i.e., Heart Rate (HR), Finger Temperature (FT), Respiration Rate (RR), Carbon dioxide (CO2) and Oxygen Saturation (SpO2) are collected during the data collection phase. Here, sensor fusion has been done in two different ways: (i) decision-level fusion using features extracted through traditional approaches; and (ii) data-level fusion using features extracted by means of Multivariate Multiscale Entropy (MMSE). Case-Based Reasoning (CBR) is applied for the classification of the signals. The experimental result shows that the proposed system could classify Stressed or Relaxed individual 87.5% accurately compare to an expert in the domain. So, it shows promising result in the psychophysiological domain and could be possible to adapt this approach to other relevant healthcare systems.

Relative Permeabilities of Plastic Films to Water and Carbon Dioxide

PubMed Central

Woolley, Joseph T.

1967-01-01

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

Investigations about the quantitative changes of carbon dioxide production in humans. Report 2: Carbon dioxide production during fever and its relationship with heat production

NASA Technical Reports Server (NTRS)

Liebermeister, C.

1978-01-01

Investigations are cited and explained for carbon dioxide production during fever and its relationship with heat production. The general topics of discussion are: (1) carbon dioxide production for alternating fever attacks; (2) heat balance during the perspiration phase; (3) heat balance during the chill phase; (4) the theory of fever; and (5) chill phase for other fever attacks.

Hydraulic studies of drilling microbores with supercritical steam, nitrogen and carbon dioxide

DOE Data Explorer

Ken Oglesby

2010-01-01

Hydraulic studies of drilling microbores at various depths and with various hole sizes, tubing, fluids and rates showed theoretical feasibility. WELLFLO SIMULATIONS REPORT STEP 4: DRILLING 10,000 FT WELLS WITH SUPERCRITICAL STEAM, NITROGEN AND CARBON DIOXIDE STEP 5: DRILLING 20,000 FT WELLS WITH SUPERCRITICAL STEAM, NITROGEN AND CARBON DIOXIDE STEP 6: DRILLING 30,000 FT WELLS WITH SUPERCRITICAL STEAM, NITROGEN AND CARBON DIOXIDE Mehmet Karaaslan, MSI

Advanced air revitalization system modeling and testing

NASA Technical Reports Server (NTRS)

Dall-Baumann, Liese; Jeng, Frank; Christian, Steve; Edeer, Marybeth; Lin, Chin

1990-01-01

To support manned lunar and Martian exploration, an extensive evaluation of air revitalization subsystems (ARS) is being conducted. The major operations under study include carbon dioxide removal and reduction; oxygen and nitrogen production, storage, and distribution; humidity and temperature control; and trace contaminant control. A comprehensive analysis program based on a generalized block flow model was developed to facilitate the evaluation of various processes and their interaction. ASPEN PLUS was used in modelling carbon dioxide removal and reduction. Several life support test stands were developed to test new and existing technologies for their potential applicability in space. The goal was to identify processes which use compact, lightweight equipment and maximize the recovery of oxygen and water. The carbon dioxide removal test stands include solid amine/vacuum desorption (SAVD), regenerative silver oxide chemisorption, and electrochemical carbon dioxide concentration (EDC). Membrane-based carbon dioxide removal and humidity control, catalytic reduction of carbon dioxide, and catalytic oxidation of trace contaminants were also investigated.

Combustion systems and power plants incorporating parallel carbon dioxide capture and sweep-based membrane separation units to remove carbon dioxide from combustion gases

DOEpatents

Wijmans, Johannes G [Menlo Park, CA; Merkel, Timothy C [Menlo Park, CA; Baker, Richard W [Palo Alto, CA

2011-10-11

Disclosed herein are combustion systems and power plants that incorporate sweep-based membrane separation units to remove carbon dioxide from combustion gases. In its most basic embodiment, the invention is a combustion system that includes three discrete units: a combustion unit, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In a preferred embodiment, the invention is a power plant including a combustion unit, a power generation system, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In both of these embodiments, the carbon dioxide capture unit and the sweep-based membrane separation unit are configured to be operated in parallel, by which we mean that each unit is adapted to receive exhaust gases from the combustion unit without such gases first passing through the other unit.

Geologic map showing springs rich in carbon dioxide or or chloride in California

USGS Publications Warehouse

Barnes, Ivan; Irwin, William P.; Gibson, H.A.

1975-01-01

Carbon dioxide- and chloride-rich springs occur in all geologic provinces in California, but are most abundant in the Coast Ranges and the Great Valley. The carbon-dioxide-rich springs issue mainly from Franciscan terrane; they also are rich in boron and are of the metamorphic type (White, 1957). Based on isotopic data, either the carbon dioxide or the water, or both, may be of metamorphic origin. Because of high magnesium values, the water of many of the carbon-dioxide-rich springs is thought to have passed through serpentinite. The chloride-rich waters are most common in rocks of the Great Valley sequence. Nearly all are more dilute than present-day sea water. The similarity in isotopic compositions of the metamorphic carbon-dioxide-rich water and the chloride-rich water may indicate a similar extent of water-rock interaction.

Effect of Novel Quercetin Titanium Dioxide-Decorated Multi-Walled Carbon Nanotubes Nanocomposite on Bacillus subtilis Biofilm Development

PubMed Central

Raie, Diana S.; Mhatre, Eisha; El-Desouki, Doaa S.; Labena, Ahmed; El-Ghannam, Gamal; Farahat, Laila A.; Youssef, Tareq; Fritzsche, Wolfgang; Kovács, Ákos T.

2018-01-01

The present work was targeted to design a surface against cell seeding and adhering of bacteria, Bacillus subtilis. A multi-walled carbon nanotube/titanium dioxide nano-power was produced via simple mixing of carbon nanotube and titanium dioxide nanoparticles during the sol-gel process followed by heat treatment. Successfully, quercetin was immobilized on the nanocomposite via physical adsorption to form a quercetin/multi-walled carbon nanotube/titanium dioxide nanocomposite. The adhesion of bacteria on the coated-slides was verified after 24 h using confocal laser-scanning microscopy. Results indicated that the quercetin/multi-walled carbon nanotube/titanium dioxide nanocomposite had more negativity and higher recovery by glass surfaces than its counterpart. Moreover, coating surfaces with the quercetin-modified nanocomposite lowered both hydrophilicity and surface-attached bacteria compared to surfaces coated with the multi-walled carbon nanotubes/titanium dioxide nanocomposite. PMID:29346268

Production of magnesium metal

DOEpatents

Blencoe, James G [Harriman, TN; Anovitz, Lawrence M [Knoxville, TN; Palmer, Donald A [Oliver Springs, TN; Beard, James S [Martinsville, VA

2012-04-10

A process of producing magnesium metal includes providing magnesium carbonate, and reacting the magnesium carbonate to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The carbon dioxide is used as a reactant in a second process. In another embodiment of the process, a magnesium silicate is reacted with a caustic material to produce magnesium hydroxide. The magnesium hydroxide is reacted with a source of carbon dioxide to produce magnesium carbonate. The magnesium carbonate is reacted to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The invention also relates to the magnesium metal produced by the processes described herein.

Results from On-Board CSA-CP and CDM Sensor Readings During the Burning and Suppression of Solids II (BASS-II) Experiment in the Microgravity Science Glovebox (MSG)

NASA Technical Reports Server (NTRS)

Olson, Sandra L.; Ferkul, Paul V.; Bhattacharjee, Subrata; Miller, Fletcher J.; Fernandez-Pello, Carlos; Link, Shmuel; T'ien, James S.; Wichman, Indrek

2015-01-01

For the first time on ISS, BASS-II utilized MSG working volume dilution with gaseous nitrogen (N2). We developed a perfectly stirred reactor model to determine the N2 flow time and flow rate to obtain the desired reduced oxygen concentration in the working volume for each test. We calibrated the model with CSA-CP oxygen readings offset using the Mass Constituents Analyzer reading of the ISS ambient atmosphere data for that day. This worked out extremely well for operations, and added a new vital variable, ambient oxygen level, to our test matrices. The main variables tested in BASS-II were ambient oxygen concentration, ventilation flow velocity, and fuel type, thickness, and geometry. BASS-II also utilized the on-board CSA-CP for oxygen and carbon monoxide readings, and the CDM for carbon dioxide readings before and after each test. Readings from these sensors allow us to evaluate the completeness of the combustion. The oxygen and carbon dioxide readings before and after each test were analyzed and compared very well to stoichiometric ratios for a one step gas-phase reaction. The CO versus CO2 followed a linear trend for some datasets, but not for all the different geometries of fuel and flow tested. Lastly, we calculated the heat release rates during each test from the oxygen consumption and burn times, using the constant 13.1 kJ of heat released per gram of oxygen consumed. The results showed that the majority of the tests had heat release rates well below 100 Watts.

The Ocean's Carbon Factory: Ocean Composition. The Growth Patterns of Phytoplankton Species

NASA Technical Reports Server (NTRS)

Gregg, Watson

2000-01-01

According to biological data recorded by the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) satellite, the ocean contains nearly half of all the Earth's photosynthesis activity. Through photosynthesis, plant life forms use carbon from the atmosphere, and in return, plants produce the oxygen that life requires. In effect, ocean chlorophyll works like a factory, taking carbon and "manufacturing" the air we breathe. Most ocean-bound photosynthesis is performed by single-celled plants called phytoplankton. "These things are so small," according to Michael Behrenfeld, a researcher at NASA Goddard Space Flight Center, "that if you take hundreds of them and stack them end-to-end, the length of that stack is only the thickness of a penny". The humble phytoplankton species plays a vital role in balancing the amounts of oxygen and carbon dioxide in the atmosphere. Therefore, understanding exactly how phytoplankton growth works is important.

Carbon Dioxide Gas Sensors and Method of Manufacturing and Using Same

NASA Technical Reports Server (NTRS)

Hunter, Gary W. (Inventor); Xu, Jennifer C. (Inventor)

2014-01-01

A gas sensor comprises a substrate layer; a pair of interdigitated metal electrodes, said electrodes include upper surfaces, the electrodes selected from the group consisting of Pt, Pd, Au, Ir, Ag, Ru, Rh, In, Os, and their alloys. A first layer of solid electrolyte staying in between electrode fingers and partially on said upper surfaces of said electrodes, said first layer selected from NASICON, LISICON, KSICON and.beta.''-Alumina. A second layer of metal carbonate(s) as an auxiliary electrolyte engaging said upper surfaces of the electrodes and the first solid electrolyte. The metal carbonates selected from the group consisting of the following ions Na.sup.+, K.sup.+, Li.sup.+, Ag.sup.+, H.sup.+, Pb.sup.2+, Sr.sup.2+, Ba.sup.2+, and any combination thereof. An extra layer of metal oxide selected from the group consisting of SnO.sub.2, In.sub.2O.sub.3, TiO.sub.2, WO.sub.3, ZnO, Fe.sub.2O.sub.3, ITO, CdO, U.sub.3O.sub.8, Ta.sub.2O.sub.5, BaO, MoO.sub.2, MoO.sub.3, V.sub.2O.sub.5, Nb.sub.2O.sub.5, CuO, Cr.sub.2O.sub.3, La.sub.2O.sub.3, RuO.sub.3, RuO.sub.2, ReO.sub.2, ReO.sub.3, Ag.sub.2O, CoO, Cu.sub.2O, SnO, NiO, Pr.sub.2O.sub.3, BaO, PdO.sub.2, HfO.sub.3, HfO.sub.3 or other metal oxide and their mixtures residing above and in engagement with the second electrolyte to improve sensor performance and/or to reduce sensor heating power consumption.

Ruthenium-catalysed alkoxycarbonylation of alkenes with carbon dioxide.

PubMed

Wu, Lipeng; Liu, Qiang; Fleischer, Ivana; Jackstell, Ralf; Beller, Matthias

2014-01-01

Alkene carbonylations represent a major technology for the production of value-added bulk and fine chemicals. Nowadays, all industrial carbonylation processes make use of highly toxic and flammable carbon monoxide. Here we show the application of abundantly available carbon dioxide as C1 building block for the alkoxycarbonylations of industrially important olefins in the presence of a convenient and inexpensive ruthenium catalyst system. In our system, carbon dioxide works much better than the traditional combination of carbon monoxide and alcohols. The unprecedented in situ formation of carbon monoxide from carbon dioxide and alcohols permits an efficient synthesis of carboxylic acid esters, which can be used as detergents and polymer-building blocks. Notably, this transformation allows the catalytic formation of C-C bonds with carbon dioxide as C1 source and avoids the use of sensitive and/or expensive reducing agents (for example, Grignard reagents, diethylzinc or triethylaluminum).

Encapsulated liquid sorbents for carbon dioxide capture

NASA Astrophysics Data System (ADS)

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

2015-02-01

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

W.A. Parish Post Combustion CO 2 Capture and Sequestration Project Final Public Design Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Armpriester, Anthony

The Petra Nova Project is a commercial scale post-combustion carbon dioxide capture project that is being developed by a joint venture between NRG Energy (NRG) and JX Nippon Oil and Gas Exploration (JX). The project is designed to separate and capture carbon dioxide from an existing coal-fired unit's flue gas slipstream at NRG's W.A. Parish Generation Station located southwest of Houston, Texas. The captured carbon dioxide will be transported by pipeline and injected into the West Ranch oil field to boost oil production. The project, which is partially funded by financial assistance from the U.S. Department of Energy will usemore » Mitsubishi Heavy Industries of America, Inc.'s Kansai Mitsubishi Carbon Dioxide Recovery (KM-CDR(R)) advanced amine-based carbon dioxide absorption technology to treat and capture at least 90% of the carbon dioxide from a 240 megawatt equivalent flue gas slipstream off of Unit 8 at W.A. Parish. The project will capture approximately 5,000 tons of carbon dioxide per day or 1.5 million tons per year that Unit 8 would otherwise emit, representing the largest commercial scale deployment of post-combustion carbon dioxide capture at a coal power plant to date. The joint venture issued full notice to proceed in July 2014 and when complete, the project is expected to be the world's largest post-combustion carbon dioxide capture facility on an existing coal plant. The detailed engineering is sufficiently complete to prepare and issue the Final Public Design Report.« less

Extraction of Carbon Dioxide and Hydrogen from Seawater and Hydrocarbon Production Therefrom

DTIC Science & Technology

2016-04-05

extracted from the acidified seawater. Optionally, the ion exchange reaction can be conducted under conditions which produce hydrogen as well as carbon dioxide. The carbon dioxide and hydrogen may be used to produce hydrocarbons.

International Space Station Carbon Dioxide Removal Assembly Testing

NASA Technical Reports Server (NTRS)

Knox, James C.

2000-01-01

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

Prototypes of newly conceived inorganic and biological sensors for health and environmental applications.

PubMed

Nicolini, Claudio; Adami, Manuela; Sartore, Marco; Bragazzi, Nicola Luigi; Bavastrello, Valter; Spera, Rosanna; Pechkova, Eugenia

2012-12-12

This paper describes the optimal implementation of three newly conceived sensors for both health and environmental applications, utilizing a wide range of detection methods and complex nanocomposites. The first one is inorganic and based on matrices of calcium oxide, the second is based on protein arrays and a third one is based on Langmuir-Blodgett laccase multi-layers. Special attention was paid to detecting substances significant to the environment (such as carbon dioxide) and medicine (drug administration, cancer diagnosis and prognosis) by means of amperometric, quartz crystal microbalance with frequency (QCM_F) and quartz crystal microbalance with dissipation monitoring (QCM_D) technologies. The resulting three implemented nanosensors are described here along with proofs of principle and their corresponding applications.

Battery outgassing sensor for electric drive vehicle energy storage systems

NASA Astrophysics Data System (ADS)

Beshay, Manal; Chandra Sekhar, Jai Ganesh; Kempen, Lothar U.

2011-06-01

Lithium-ion batteries have been proven efficient as high power density and low self-discharge rate energy storage systems, specifically in electrical drive vehicles. An important safety factor associated with these systems is the potential hazardous release and outgassing of toxic chemical vapors such as hydrogen fluoride (HF) and hydrogen sulfides (H2S), and relatively elevated levels of carbon dioxide (CO2). The release and accumulation of such gases emphasizes an in-line monitoring need. Intelligent Optical Systems, Inc. (IOS) has identified a viable approach for the development of an onboard optical sensor array that can be used to monitor battery outgassing. This paper discusses the potential of developing a battery outgas sensing approach that will meet sensitivity and response time requirements.

WSN based indoor air quality monitoring in classrooms

NASA Astrophysics Data System (ADS)

Wang, S. K.; Chew, S. P.; Jusoh, M. T.; Khairunissa, A.; Leong, K. Y.; Azid, A. A.

2017-03-01

Indoor air quality monitoring is essential as the human health is directly affected by indoor air quality. This paper presents the investigations of the impact of undergraduate students' concentration during lecture due to the indoor air quality in classroom. Three environmental parameters such as temperature, relative humidity and concentration of carbon dioxide are measured using wireless sensor network based air quality monitoring system. This simple yet reliable system is incorporated with DHT-11 and MG-811 sensors. Two classrooms were selected to install the monitoring system. The level of indoor air quality were measured and students' concentration was assessed using intelligent test during normal lecturing section. The test showed significant correlation between the collected environmental parameters and the students' level of performances in their study.

Metal oxide nanostructures: preparation, characterization and functional applications as chemical sensors.

PubMed

Zappa, Dario; Bertuna, Angela; Comini, Elisabetta; Kaur, Navpreet; Poli, Nicola; Sberveglieri, Veronica; Sberveglieri, Giorgio

2017-01-01

Preparation and characterization of different metal oxide (NiO, WO 3 , ZnO, SnO 2 and Nb 2 O 5 ) nanostructures for chemical sensing are presented. p-Type (NiO) and n-type (WO 3 , SnO 2 , ZnO and Nb 2 O 5 ) metal oxide nanostructures were grown on alumina substrates using evaporation-condensation, thermal oxidation and hydrothermal techniques. Surface morphologies and crystal structures were investigated through scanning electron microscopy and Raman spectroscopy. Furthermore, different batches of sensors have been prepared, and their sensing performances towards carbon monoxide and nitrogen dioxide have been explored. Moreover, metal oxide nanowires have been integrated into an electronic nose and successfully applied to discriminate between drinking and contaminated water.

Method for enhanced oil recovery

DOEpatents

Comberiati, Joseph R.; Locke, Charles D.; Kamath, Krishna I.

1980-01-01

The present invention is directed to an improved method for enhanced recovery of oil from relatively "cold" reservoirs by carbon dioxide flooding. In oil reservoirs at a temperature less than the critical temperature of 87.7.degree. F. and at a pore pressure greater than the saturation pressure of carbon dioxide at the temperature of the reservoir, the carbon dioxide remains in the liquid state which does not satisfactorily mix with the oil. However, applicants have found that carbon dioxide can be vaporized in situ in the reservoir by selectively reducing the pore pressure in the reservoir to a value less than the particular saturated vapor pressure so as to greatly enhance the mixing of the carbon dioxide with the oil.

Decreased abundance of crustose coralline algae due to ocean acidification

USGS Publications Warehouse

Kuffner, Ilsa B.; Andersson, Andreas J; Jokiel, Paul L.; Rodgers, Ku'ulei S.; Mackenzie, Fred T.

2008-01-01

Owing to anthropogenic emissions, atmospheric concentrations of carbon dioxide could almost double between 2006 and 2100 according to business-as-usual carbon dioxide emission scenarios1. Because the ocean absorbs carbon dioxide from the atmosphere2, 3, 4, increasing atmospheric carbon dioxide concentrations will lead to increasing dissolved inorganic carbon and carbon dioxide in surface ocean waters, and hence acidification and lower carbonate saturation states2, 5. As a consequence, it has been suggested that marine calcifying organisms, for example corals, coralline algae, molluscs and foraminifera, will have difficulties producing their skeletons and shells at current rates6, 7, with potentially severe implications for marine ecosystems, including coral reefs6, 8, 9, 10, 11. Here we report a seven-week experiment exploring the effects of ocean acidification on crustose coralline algae, a cosmopolitan group of calcifying algae that is ecologically important in most shallow-water habitats12, 13, 14. Six outdoor mesocosms were continuously supplied with sea water from the adjacent reef and manipulated to simulate conditions of either ambient or elevated seawater carbon dioxide concentrations. The recruitment rate and growth of crustose coralline algae were severely inhibited in the elevated carbon dioxide mesocosms. Our findings suggest that ocean acidification due to human activities could cause significant change to benthic community structure in shallow-warm-water carbonate ecosystems.

46 CFR 95.15-1 - Application.

Code of Federal Regulations, 2011 CFR

2011-10-01

... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-1 Application. (a) Where a carbon dioxide... are based on a “high pressure system,” i.e., one in which the carbon dioxide is stored in liquid form at atmospheric temperature. Details for “low pressure systems,” i. e., those in which the carbon...

46 CFR 95.15-1 - Application.

Code of Federal Regulations, 2012 CFR

2012-10-01

... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-1 Application. (a) Where a carbon dioxide... are based on a “high pressure system,” i.e., one in which the carbon dioxide is stored in liquid form at atmospheric temperature. Details for “low pressure systems,” i. e., those in which the carbon...

46 CFR 95.15-1 - Application.

Code of Federal Regulations, 2013 CFR

2013-10-01

... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-1 Application. (a) Where a carbon dioxide... are based on a “high pressure system,” i.e., one in which the carbon dioxide is stored in liquid form at atmospheric temperature. Details for “low pressure systems,” i. e., those in which the carbon...

46 CFR 95.15-1 - Application.

Code of Federal Regulations, 2014 CFR

2014-10-01

... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-1 Application. (a) Where a carbon dioxide... are based on a “high pressure system,” i.e., one in which the carbon dioxide is stored in liquid form at atmospheric temperature. Details for “low pressure systems,” i. e., those in which the carbon...

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

ERIC Educational Resources Information Center

Brewer, Carol A.; Beiswenger, Jane M.

1993-01-01

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

Determination of diffusion coefficients of carbon dioxide in water between 268 and 473 K in a high-pressure capillary optical cell with in situ Raman spectroscopic measurements

USGS Publications Warehouse

Lu, Wanjun; Guo, Huirong; Chou, I.-Ming; Burruss, R.C.; Li, Lanlan

2013-01-01

Accurate values of diffusion coefficients for carbon dioxide in water and brine at reservoir conditions are essential to our understanding of transport behavior of carbon dioxide in subsurface pore space. However, the experimental data are limited to conditions at low temperatures and pressures. In this study, diffusive transfer of carbon dioxide in water at pressures up to 45 MPa and temperatures from 268 to 473 K was observed within an optical capillary cell via time-dependent Raman spectroscopy. Diffusion coefficients were estimated by the least-squares method for the measured variations in carbon dioxide concentration in the cell at various sample positions and time. At the constant pressure of 20 MPa, the measured diffusion coefficients of carbon dioxide in water increase with increasing temperature from 268 to 473 K. The relationship between diffusion coefficient of carbon dioxide in water [D(CO2) in m2/s] and temperature (T in K) was derived with Speedy–Angell power-law approach as: D(CO2)=D0[T/Ts-1]m where D0 = 13.942 × 10−9 m2/s, Ts = 227.0 K, and m = 1.7094. At constant temperature, diffusion coefficients of carbon dioxide in water decrease with pressure increase. However, this pressure effect is rather small (within a few percent).

A new look at atmospheric carbon dioxide

NASA Astrophysics Data System (ADS)

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

Carbon dioxide is increasing in the atmosphere and is of considerable concern in global climate change because of its greenhouse gas warming potential. The rate of increase has accelerated since measurements began at Mauna Loa Observatory in 1958 where carbon dioxide increased from less than 1 part per million per year (ppm yr -1) prior to 1970 to more than 2 ppm yr -1 in recent years. Here we show that the anthropogenic component (atmospheric value reduced by the pre-industrial value of 280 ppm) of atmospheric carbon dioxide has been increasing exponentially with a doubling time of about 30 years since the beginning of the industrial revolution (˜1800). Even during the 1970s, when fossil fuel emissions dropped sharply in response to the "oil crisis" of 1973, the anthropogenic atmospheric carbon dioxide level continued increasing exponentially at Mauna Loa Observatory. Since the growth rate (time derivative) of an exponential has the same characteristic lifetime as the function itself, the carbon dioxide growth rate is also doubling at the same rate. This explains the observation that the linear growth rate of carbon dioxide has more than doubled in the past 40 years. The accelerating growth rate is simply the outcome of exponential growth in carbon dioxide with a nearly constant doubling time of about 30 years (about 2%/yr) and appears to have tracked human population since the pre-industrial era.

Monitoring of Carbon Dioxide and Methane Plumes from Combined Ground-Airborne Sensors

NASA Astrophysics Data System (ADS)

Jacob, Jamey; Mitchell, Taylor; Honeycutt, Wes; Materer, Nicholas; Ley, Tyler; Clark, Peter

2016-11-01

A hybrid ground-airborne sensing network for real-time plume monitoring of CO2 and CH4 for carbon sequestration is investigated. Conventional soil gas monitoring has difficulty in distinguishing gas flux signals from leakage with those associated with meteorologically driven changes. A low-cost, lightweight sensor system has been developed and implemented onboard a small unmanned aircraft and is combined with a large-scale ground network that measures gas concentration. These are combined with other atmospheric diagnostics, including thermodynamic data and velocity from ultrasonic anemometers and multi-hole probes. To characterize the system behavior and verify its effectiveness, field tests have been conducted with simulated discharges of CO2 and CH4 from compressed gas tanks to mimic leaks and generate gaseous plumes, as well as field tests over the Farnsworth CO2-EOR site in the Anadarko Basin. Since the sensor response time is a function of vehicle airspeed, dynamic calibration models are required to determine accurate location of gas concentration in space and time. Comparisons are made between the two tests and results compared with historical models combining both flight and atmospheric dynamics. Supported by Department of Energy Award DE-FE0012173.

Personal Cabin Pressure Monitor and Warning System

NASA Technical Reports Server (NTRS)

Zysko, Jan A. (Inventor)

2002-01-01

A cabin pressure altitude monitor and warning system provides a warning when a detected cabin pressure altitude has reached a predetermined level. The system is preferably embodied in a portable, pager-sized device that can be carried or worn by an individual. A microprocessor calculates the pressure altitude from signals generated by a calibrated pressure transducer and a temperature sensor that compensates for temperature variations in the signals generated by the pressure transducer. The microprocessor is programmed to generate a warning or alarm if a cabin pressure altitude exceeding a predetermined threshold is detected. Preferably, the microprocessor generates two different types of warning or alarm outputs, a first early warning or alert when a first pressure altitude is exceeded. and a second more serious alarm condition when either a second. higher pressure altitude is exceeded, or when the first pressure altitude has been exceeded for a predetermined period of time. Multiple types of alarm condition indicators are preferably provided, including visual, audible and tactile. The system is also preferably designed to detect gas concentrations and other ambient conditions, and thus incorporates other sensors, such as oxygen, relative humidity, carbon dioxide, carbon monoxide and ammonia sensors, to provide a more complete characterization and monitoring of the local environment.

Comparative study on CO2 and CO sensing performance of LaOCl-coated ZnO nanowires.

PubMed

Van Hieu, Nguyen; Khoang, Nguyen Duc; Trung, Do Dang; Toan, Le Duc; Van Duy, Nguyen; Hoa, Nguyen Duc

2013-01-15

Carbon dioxide (CO(2)) and carbon monoxide (CO) emissions from industries and combustion fuels such as coal, oil, hydrocarbon, and natural gases are increasing, thus causing environmental pollution and climate change. The selective detection of CO(2) and CO gases is important for environmental monitoring and industrial safety applications. In this work, LaOCl-coated ZnO nanowires (NWs) sensors are fabricated and characterized for the detection of CO(2) (250-4000 ppm) and CO (10-200 ppm) gases at different operating temperatures. The effects of the LaCl(3) coating concentration and calcination temperature of the sensors are studied. They are found to have a strong influence on the sensing performance to CO(2) gas, but a relatively slight influence on that to CO. The LaOCl coating enhances the response and shortens the response and recovery times to CO(2) compared with those to CO. The enhanced response of the LaOCl-coated ZnO NW sensors is attributed to the extension of the electron depletion layer due to the formation of p-LaOCl/n-ZnO junctions on the surfaces of the ZnO NWs. Copyright © 2012 Elsevier B.V. All rights reserved.

Personal Cabin Pressure Monitor and Warning System

NASA Astrophysics Data System (ADS)

Zysko, Jan A.

2002-09-01

A cabin pressure altitude monitor and warning system provides a warning when a detected cabin pressure altitude has reached a predetermined level. The system is preferably embodied in a portable, pager-sized device that can be carried or worn by an individual. A microprocessor calculates the pressure altitude from signals generated by a calibrated pressure transducer and a temperature sensor that compensates for temperature variations in the signals generated by the pressure transducer. The microprocessor is programmed to generate a warning or alarm if a cabin pressure altitude exceeding a predetermined threshold is detected. Preferably, the microprocessor generates two different types of warning or alarm outputs, a first early warning or alert when a first pressure altitude is exceeded. and a second more serious alarm condition when either a second. higher pressure altitude is exceeded, or when the first pressure altitude has been exceeded for a predetermined period of time. Multiple types of alarm condition indicators are preferably provided, including visual, audible and tactile. The system is also preferably designed to detect gas concentrations and other ambient conditions, and thus incorporates other sensors, such as oxygen, relative humidity, carbon dioxide, carbon monoxide and ammonia sensors, to provide a more complete characterization and monitoring of the local environment.

An oil-based model of inhalation anesthetic uptake and elimination.

PubMed

Loughlin, P J; Bowes, W A; Westenskow, D R

1989-08-01

An oil-based model was developed as a physical simulation of inhalation anesthetic uptake and elimination. It provides an alternative to animal models in testing the performance of anesthesia equipment. A 7.5-1 water-filled manometer simulates pulmonary mechanics. Nitrogen and carbon dioxide flowing into the manometer simulate oxygen consumption and carbon dioxide production. Oil-filled chambers (180 ml and 900 ml) simulate the uptake and washout of halothane by the vessel-rich and muscle tissue groups. A 17.2-1 air-filled chamber simulates uptake by the lung group. Gas circulates through the chambers (3.7, 13.8, and 25 l/min) to simulate the transport of anesthetic to the tissues by the circulatory system. Results show that during induction and washout, the rate of rise in endtidal halothane fraction simulated by the model parallels that measured in patients. The model's end-tidal fraction changes correctly with changes in cardiac output and alveolar ventilation. The model has been used to test anesthetic controllers and to evaluate gas sensors, and should be useful in teaching principles underlying volatile anesthetic uptake.

Thickness Map of Buried Carbon-Dioxide Deposit

NASA Image and Video Library

2011-04-21

NASA Mars Reconnaissance Orbiter color-codes thickness estimates in a newly found, buried deposit of frozen carbon dioxide, dry ice, near the south pole of Mars contains ~30 times more carbon dioxide than previously estimated to be frozen near the pole.

Organic syntheses employing supercritical carbon dioxide as a reaction solvent

NASA Technical Reports Server (NTRS)

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

1991-01-01

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

Organic syntheses employing supercritical carbon dioxide as a reaction solvent

NASA Technical Reports Server (NTRS)

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

1993-01-01

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

A low-cost sensor for high density urban CO2 monitoring

NASA Astrophysics Data System (ADS)

Zeng, N.; Martin, C.

2015-12-01

The high spatial-termporal variability of greenhouse gases and other pollution sources in an urban environment can not be easily resolved with current high-accuracy but expensive instruments. We have tested a small, low-cost NDIR CO2 sensor designed for potential use. It has a manufacturer's specified accuracy of +- 30 parts per million (ppm). However, initial results running parallel with a research-grade greenhouse gas analyzer have shown that the absolute accuracy of the sensor is within +-5ppm, suggesting their utility for sensing ambient air variations in carbon dioxide. Through a multivariate analysis, we have determined a correction procedure that when accounting for environmental temperature, humidity, air pressure, and the device's span and offset, we can further increase the accuracy of the collected data. We will show results from rooftop measurements over a period of one year and CO2 tracking data in the Washington-Baltimore Metropolitan area.

Selective Formation of Trimethylene Carbonate (TMC): Atmospheric Pressure Carbon Dioxide Utilization

PubMed Central

Buckley, Benjamin R; Patel, Anish P; Wijayantha, K G Upul

2015-01-01

Carbon dioxide utilisation (CDU) is currently gaining increased interest due to the abundance of CO2 and its possible application as a C1 building block. We herein report the first example of atmospheric pressure carbon dioxide incorporation into oxetane to selectively form trimethylene carbonate (TMC), which is a significant challenge as TMC is thermodynamically less favoured than its corresponding co-polymer. PMID:26213485

Selective Formation of Trimethylene Carbonate (TMC): Atmospheric Pressure Carbon Dioxide Utilization.

PubMed

Buckley, Benjamin R; Patel, Anish P; Wijayantha, K G Upul

2015-01-01

Carbon dioxide utilisation (CDU) is currently gaining increased interest due to the abundance of CO 2 and its possible application as a C 1 building block. We herein report the first example of atmospheric pressure carbon dioxide incorporation into oxetane to selectively form trimethylene carbonate (TMC), which is a significant challenge as TMC is thermodynamically less favoured than its corresponding co-polymer.

The causal nexus between carbon dioxide emissions and agricultural ecosystem-an econometric approach.

PubMed

Asumadu-Sarkodie, Samuel; Owusu, Phebe Asantewaa

2017-01-01

Achieving a long-term food security and preventing hunger include a better nutrition through sustainable systems of production, distribution, and consumption. Nonetheless, the quest for an alternative to increasing global food supply to meet the growing demand has led to the use of poor agricultural practices that promote climate change. Given the contribution of the agricultural ecosystem towards greenhouse gas (GHG) emissions, this study investigated the causal nexus between carbon dioxide emissions and agricultural ecosystem by employing a data spanning from 1961 to 2012. Evidence from long-run elasticity shows that a 1 % increase in the area of rice paddy harvested will increase carbon dioxide emissions by 1.49 %, a 1 % increase in biomass-burned crop residues will increase carbon dioxide emissions by 1.00 %, a 1 % increase in cereal production will increase carbon dioxide emissions by 1.38 %, and a 1 % increase in agricultural machinery will decrease carbon dioxide emissions by 0.09 % in the long run. There was a bidirectional causality between carbon dioxide emissions, cereal production, and biomass-burned crop residues. The Granger causality shows that the agricultural ecosystem in Ghana is sensitive to climate change vulnerability.

Methods and systems for producing syngas

DOEpatents

Hawkes, Grant L; O& #x27; Brien, James E; Stoots, Carl M; Herring, J. Stephen; McKellar, Michael G; Wood, Richard A; Carrington, Robert A; Boardman, Richard D

2013-02-05

Methods and systems are provided for producing syngas utilizing heat from thermochemical conversion of a carbonaceous fuel to support decomposition of at least one of water and carbon dioxide using one or more solid-oxide electrolysis cells. Simultaneous decomposition of carbon dioxide and water or steam by one or more solid-oxide electrolysis cells may be employed to produce hydrogen and carbon monoxide. A portion of oxygen produced from at least one of water and carbon dioxide using one or more solid-oxide electrolysis cells is fed at a controlled flow rate in a gasifier or combustor to oxidize the carbonaceous fuel to control the carbon dioxide to carbon monoxide ratio produced.

Ocean Fertilization for Sequestration of Carbon Dioxide from the Atmosphere

NASA Astrophysics Data System (ADS)

Boyd, Philip W.

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

Open-cycle magnetohydrodynamic power plant with CO.sub.2 recycling

DOEpatents

Berry, Gregory F.

1991-01-01

A method of converting the chemical energy of fossil fuel to electrical and mechanical energy with a MHD generator. The fossil fuel is mixed with preheated oxygen and carbon dioxide and a conducting seed of potassium carbonate to form a combustive and electrically conductive mixture which is burned in a combustion chamber. The burned combustion mixture is passed through a MHD generator to generate electrical energy. The burned combustion mixture is passed through a diffuser to restore the mixture approximately to atmospheric pressure, leaving a spent combustion mixture which is used to heat oxygen from an air separation plant and recycled carbon dioxide for combustion in a high temperature oxygen preheater and for heating water/steam for producing superheated steam. Relatively pure carbon dioxide is separated from the spent combustion mixture for further purification or for exhaust, while the remainder of the carbon dioxide is recycled from the spent combustion mixture to a carbon dioxide purification plant for removal of water and any nitrous oxides present, leaving a greater than 98% pure carbon dioxide. A portion of the greater then 98% pure carbon dioxide stream is recovered and the remainder is recycled to combine with the oxygen for preheating and combination with the fossil fuel to form a combustion mixture.

Method of determining pH by the alkaline absorption of carbon dioxide

DOEpatents

Hobbs, David T.

1992-01-01

A method for measuring the concentration of hydroxides in alkaline solutions in a remote location using the tendency of hydroxides to absorb carbon dioxide. The method includes the passing of carbon dioxide over the surface of an alkaline solution in a remote tank before and after measurements of the carbon dioxide solution. A comparison of the measurements yields the absorption fraction from which the hydroxide concentration can be calculated using a correlation of hydroxide or pH to absorption fraction.

Supercritical carbon dioxide: a solvent like no other

PubMed Central

Peach, Jocelyn

2014-01-01

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

Numerical simulation of injection process of warm carbon dioxide into layer saturated with methane and its hydrate

NASA Astrophysics Data System (ADS)

Khasanov, M. K.; Stolpovsky, M. V.; Gimaltdinov, I. K.

2018-05-01

In this article, in a flat-one-dimensional approximation, a mathematical model is presented for injecting warm carbon dioxide into a methane hydrate formation of finite length. It is established that the model of formation of hydrate of carbon dioxide in the absence of an area saturated with methane and water, under certain parameters, leads to thermodynamic contradiction. The mathematical model of carbon dioxide injection with formation of the region saturated with methane and water is constructed.

Reduction of Carbon Dioxide by a Molybdenum-Containing Formate Dehydrogenase: A Kinetic and Mechanistic Study.

PubMed

Maia, Luisa B; Fonseca, Luis; Moura, Isabel; Moura, José J G

2016-07-20

Carbon dioxide accumulation is a major concern for the ecosystems, but its abundance and low cost make it an interesting source for the production of chemical feedstocks and fuels. However, the thermodynamic and kinetic stability of the carbon dioxide molecule makes its activation a challenging task. Studying the chemistry used by nature to functionalize carbon dioxide should be helpful for the development of new efficient (bio)catalysts for atmospheric carbon dioxide utilization. In this work, the ability of Desulfovibrio desulfuricans formate dehydrogenase (Dd FDH) to reduce carbon dioxide was kinetically and mechanistically characterized. The Dd FDH is suggested to be purified in an inactive form that has to be activated through a reduction-dependent mechanism. A kinetic model of a hysteretic enzyme is proposed to interpret and predict the progress curves of the Dd FDH-catalyzed reactions (initial lag phase and subsequent faster phase). Once activated, Dd FDH is able to efficiently catalyze, not only the formate oxidation (kcat of 543 s(-1), Km of 57.1 μM), but also the carbon dioxide reduction (kcat of 46.6 s(-1), Km of 15.7 μM), in an overall reaction that is thermodynamically and kinetically reversible. Noteworthy, both Dd FDH-catalyzed formate oxidation and carbon dioxide reduction are completely inactivated by cyanide. Current FDH reaction mechanistic proposals are discussed and a different mechanism is here suggested: formate oxidation and carbon dioxide reduction are proposed to proceed through hydride transfer and the sulfo group of the oxidized and reduced molybdenum center, Mo(6+)═S and Mo(4+)-SH, are suggested to be the direct hydride acceptor and donor, respectively.

Green hydrophilic interaction chromatography using ethanol-water-carbon dioxide mixtures.

PubMed

Pereira, Alberto dos Santos; Girón, Ana Jiménez; Admasu, Engdawork; Sandra, Pat

2010-03-01

In hydrophilic interaction chromatography (HILIC), best results are obtained with high concentrations of acetonitrile. In the framework of green chromatography, different concentrations of carbon dioxide were added to the mobile phases acetonitrile-water and ethanol-water and the impact on retention and separation in HILIC using bare silica as stationary phase was explored. The features of HILIC using enhanced-fluidity mobile phases are illustrated with the analysis of the nucleobases and a mixture containing the nucleobases and cortisol, flurbiprofen, theophylline and caffeine. For both organic constituents, the elution window is widened in function of the carbon dioxide concentration and selectivity changes. At high concentrations of carbon dioxide in ethanol, separations were similar to those obtained with acetonitrile without carbon dioxide addition.

Membrane loop process for separating carbon dioxide for use in gaseous form from flue gas

DOEpatents

Wijmans, Johannes G; Baker, Richard W; Merkel, Timothy C

2014-10-07

The invention is a process involving membrane-based gas separation for separating and recovering carbon dioxide emissions from combustion processes in partially concentrated form, and then transporting the carbon dioxide and using or storing it in a confined manner without concentrating it to high purity. The process of the invention involves building up the concentration of carbon dioxide in a gas flow loop between the combustion step and a membrane separation step. A portion of the carbon dioxide-enriched gas can then be withdrawn from this loop and transported, without the need to liquefy the gas or otherwise create a high-purity stream, to a destination where it is used or confined, preferably in an environmentally benign manner.

Carbon capture by sorption-enhanced water-gas shift reaction process using hydrotalcite-based material

DOE Office of Scientific and Technical Information (OSTI.GOV)

van Selow, E.R.; Cobden, P.D.; Verbraeken, P.A.

2009-05-15

A novel route for precombustion decarbonization is the sorption-enhanced water-gas shift (SEWGS) process. In this process carbon dioxide is removed from a synthesis gas at elevated temperature by adsorption. Simultaneously, carbon monoxide is converted to carbon dioxide by the water-gas shift reaction. The periodic adsorption and desorption of carbon dioxide is induced by a pressure swing cycle, and the cyclic capacity can be amplified by purging with steam. From previous studies is it known that for SEWGS applications, hydrotalcite-based materials are particularly attractive as sorbent, and commercial high-temperature shift catalysts can be used for the conversion of carbon monoxide. Tabletsmore » of a potassium promoted hydrotalcite-based material are characterized in both breakthrough and cyclic experiments in a 2 m tall fixed-bed reactor. When exposed to a mixture of carbon dioxide, steam, and nitrogen at 400{sup o}C, the material shows a breakthrough capacity of 1.4 mmol/g. In subsequent experiments the material was mixed with tablets of promoted iron-chromium shift catalyst and exposed to a mixture of carbon dioxide, carbon monoxide, steam, hydrogen, and nitrogen. It is demonstrated that carbon monoxide conversion can be enhanced to 100% in the presence of a carbon dioxide sorbent. At breakthrough, carbon monoxide and carbon dioxide simultaneously appear at the end of the bed. During more than 300 cycles of adsorption/reaction and desorption, the capture rate, and carbon monoxide conversion are confirmed to be stable. Two different cycle types are investigated: one cycle with a CO{sub 2} rinse step and one cycle with a steam rinse step. The performance of both SEWGS cycles are discussed.« less