Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Air Sampling”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 397 records · Page 22
All sourcesNASA NTRSDOE OSTI
NASA NTRS2005

A Portable Electronic Nose for Toxic Vapor Detection, Identification, and Quantification

The Space Program and military use large quantities of hydrazine and monomethyl hydrazine as rocket propellant, which are very toxic and suspected human carcinogens. Current off-the-shelf portable instruments require 10 to 20 minutes of exposure to detect these compounds at the minimum required concentrations and are prone to false positives, making them unacceptable for many operations. In addition, post-mission analyses of grab bag air samples from the Shuttle have confirmed the occasional presence of on-board volatile organic contaminants, which also need to be monitored to ensure crew safety. A new prototype instrument based on electronic nose (e-nose) technology has demonstrated the ability to qualify (identify) and quantify many of these vapors at their minimum required concentrations, and may easily be adapted to detect many other toxic vapors. To do this, it was necessary to develop algorithms to classify unknown vapors, recognize when a vapor is not any of the vapors of interest, and estimate the concentrations of the contaminants. This paper describes the design of the portable e-nose instrument, test equipment setup, test protocols, pattern recognition algorithms, concentration estimation methods, and laboratory test results.

Linnell, B. R.↗
NASA NTRS2014

Performance Evaluation of the Operational Air Quality Monitor for Water Testing Aboard the International Space Station

Real-time environmental monitoring on ISS is necessary to provide data in a timely fashion and to help ensure astronaut health. Current real-time water TOC monitoring provides high-quality trending information, but compound-specific data is needed. The combination of ETV with the AQM showed that compounds of interest could be liberated from water and analyzed in the same manner as air sampling. Calibration of the AQM using water samples allowed for the quantitative analysis of ISS archival samples. Some calibration issues remain, but the excellent accuracy of DMSD indicates that ETV holds promise for as a sample introduction method for water analysis in spaceflight.

Wallace, William T.↗
NASA NTRS2015

Double-Pulsed 2-Micrometer Lidar Validation for Atmospheric CO2 Measurements

A double-pulsed, 2-micron Integrated Path Differential Absorption (IPDA) lidar instrument for atmospheric carbon dioxide (CO2) measurements is successfully developed at NASA Langley Research Center (LaRC). Based on direct detection technique, the instrument can be operated on ground or onboard a small aircraft. Key features of this compact, rugged and reliable IPDA lidar includes high transmitted laser energy, wavelength tuning, switching and locking, and sensitive detection. As a proof of concept, the IPDA ground and airborne CO2 measurement and validation will be presented. IPDA lidar CO2 measurements ground validation were conducted at NASA LaRC using hard targets and a calibrated in-situ sensor. Airborne validation, conducted onboard the NASA B-200 aircraft, included CO2 plum detection from power stations incinerators, comparison to in-flight CO2 in-situ sensor and comparison to air sampling at different altitude conducted by NOAA at the same site. Airborne measurements, spanning for 20 hours, were obtained from different target conditions. Ground targets included soil, vegetation, sand, snow and ocean. In addition, cloud slicing was examined over the ocean. These flight validations were conducted at different altitudes, up to 7 km, with different wavelength controlled weighing functions. CO2 measurement results agree with modeling conducted through the different sensors, as will be discussed.

Singh, Upendra N.↗
NASA NTRS2018

Representativeness of CO and O3 Along ATom Transects Derived from GEOS-5 and GMI-CTM Simulations

One major goal for the NASA Atmospheric Tomography Mission (ATom) is producing an observation-based chemical climatology to represent the atmospheric heterogeneity. In this study, we use CO and O3 observations and global atmospheric model simulations to examine the spatial representativeness of the ATom-1 and -2 transects within a 4D framework provided by the NASA GEOS-5 and GMI-CTM models. Based on the probability density functions, we find that the variability of CO and O3 along the flight tracks is well hindcast by the model when sampled per ATom flights. The CO variations along the ATom-transect are likely representative of the typical CO variations over the whole Pacific basin during both the ATom-1 and -2 periods, the northern Atlantic during the ATom-1 period, and the tropical Atlantic in the ATom-2 period. Over southern Atlantic, CO along the ATom-1 transects is likely less well mixed than that of the broader region, but is still representative of the median CO concentration. CO along the ATom-2 transect is likely higher than the median CO concentration over this region. For O3, the agreements between PDFs of O3 sampled along the ATom transects and over the broader regions are fair to good over all six regions (Scores > 0.65) with notable discrepancies over some regions. For example, in ATom-1 over the northern Pacific and Atlantic, the transect samples air masses with higher O3 levels. During ATom-2, the transect over-represents the occurrence of O3 plumes over tropical Pacific. Over the southern Pacific and Atlantic for both ATom-1 and -2, the transects have a less uniform distribution compared to the surrounding basins, but still represent the median O3 abundance. Overall, we conclude in most cases that ATom measurements represent the statistical variations of these two species over the ocean basins at the time of measurement. Higher-order statistics, including covariance of species, has not been tested in this study.

ozone↗
NASA NTRS2019

Total Temperature Measurements in Icing Cloud Flows Using a Rearward Facing Probe

This paper reports on temperature and humidity measurements from a series of ice-crystal icing tunnel experiments conducted in June 2018 at the Propulsion Systems Laboratory at the NASA Glenn Research Center. The tests were fundamental in nature and were aimed at investigating the icing processes on a two-dimensional NACA0012 airfoil subjected to artificially generated icing clouds. Prior to the tests on the airfoil, a suite of instruments, including total temperature and humidity probes, were used to characterize the thermodynamic flow and icing cloud conditions of the facility. Two different total temperature probes were used in these tests which included a custom designed rearward facing probe and a commercial self-heating total temperature probe. The rearward facing probe, the main total temperature probe, was designed to reduce and mitigate the contaminating effects of icing and ingestion of ice crystals and water droplets at the probe's inlet. The probe also serves as an air-sample inlet for a light absorption based humidity measurement. The paper includes a section which discusses total temperature and humidity measurement considerations, and another section which provides an analysis of the main probe's performance characteristics. A computational fluid dynamic model of the flow around the probe was also conducted to gain insight into the trajectory of the flow entering the probe inlet. The experiments included a series of tests in which the relative humidity of the facility flow was swept through with increasingly larger values. The data showed that the rearward facing probe can reasonably capture the flow's total temperature and humidity under mild to moderate icing conditions but produces anomalous results under more intense icing conditions. The experimental data was also compared to an in-house developed thermodynamic model which takes into account the interaction of the main flow with the icing cloud. Comparison to the thermodynamic model showed that the rearward facing probe measured the predicted trends.

Agui, Juan H.↗
NASA NTRS2021

C-5 Electrical Substation (SWMU 066) Performance Monitoring Report

The C-5 Electrical Substation (C5ES) is a National Aeronautics and Space Administration (NASA) operated electrical power substation located at the John F. Kennedy Space Center (KSC), Florida. This facility has been designated Solid Waste Management Unit (SWMU) 066 under KSC’s Resource Conservation and Recovery Act (RCRA) Corrective Action program. This Performance Monitoring Report (PMR) presents the Interim Measure (IM) activities, including baseline sampling, air sparge system construction and operation, and performance monitoring, that were completed to remediate chlorinated volatile organic compounds (CVOC) in groundwater exceeding the Florida Department of Environmental Protection (FDEP) natural attenuation default concentrations (NADC).

Andrew Scott Starr↗
NASA NTRSDate not supplied

Detecting Volcanic Co2 Emissions Hidden in Tropical Volcanic Forests Using Fixed-Wing sUAS

CO2 emissions are among the earliest indicators of subsurface state change and reactivation of volcanic systems and these deep signals reflect in faint diffuse emissions variations on volcanic flanks. Monitoring vast areas of rainforests covering tropical volcanoes is challenging, and space-borne sensors like OCO-2 are not sensitive enough. Fortunately, trees exposed to mild enhancements of CO2 may experience fertilization and build excess CO2 into excess biomass (Cawse-Nicholson, et al. 2018, Biogeosciences). They also process excess CO2 through photosynthesis, measurable by fluorescence (Bogue et al., 2019, Biogeosciences). Furthermore, spaceborne remote sensing instruments have demonstrated increasing NDVI months to years before eruptions, unexplained by other factors (e.g., Houlie et al. 2006, EPSL; Seiler et al. 2017, PLoS One). By providing a means to map large areas of above-canopy CO2 variations over tropical rainforest on the flanks of actively degassing volcanoes, we enable to interpret the signals plants provide in response to excess CO2 with airborne and spaceborne hyperspectral remote sensing methods, including a possible future Surface Biology and Geology (SBG) NASA satellite mission.As a critical step to mature and test this concept, we deployed small unmanned aerial systems (sUAS) using a fixed-wing sUAS designed for autonomous operations and long endurance in extreme environments, without causing significant disturbance of the sampled air. We integrated an in-situ sensor to record the CO2 enhancement field above the forest canopy. Test flight results on the flanks of Turrialba volcano in Costa Rica above forest canopies covering known moderate gas seeps demonstrate the sUAS-borne detection and mapping capabilities of above-canopy elevated CO2 gradients. The strong detection capabilities and high detector signal stability resulted from key system design elements including RF shielding, mechanical stabilization, and calibration procedures. This highly robust system is readily applied for diffuse volcanic CO2 emission studies on active volcanoes covered by dense vegetation.

Volcanic↗
DOE OSTI2014

First Look at Smoke Emissions from Prescribed Burns in Long-unburned Longleaf Pine Forests

While fire has long played a role in the longleaf pine ecosystem, there are still some stands in the southeastern United States where fire has not been reintroduced and fuels have accumulated for 50 years or more. As part of a larger study examining fuel loading and smoke emissions on Department of Defense installations in the southeastern U.S., fuels and trace emissions were measured during three prescribed burns at Ft. Jackson Army Base near Columbia, South Carolina in November 2011. These pine-forest understory fires provided valuable emissions data for fires that burned in stands that had little or no exposure to fire for decades. Smoke emissions were measured on the ground and from an aircraft by scientists from a large team of atmospheric researchers. (Akagi et al., 2013) To characterize initial emissions in the lofted plume and in point sources of residual smoldering combustion, trace-gas species were measured using an airborne FTIR and a ground-based FTIR, respectively. Whole-air sampling canisters were also collected from both ground- and airborne-based platforms. A total of 97 trace gases were quantified in this work, largely via infrared spectroscopy. Selected emissions data were compared with similar data collected from prescribed burns sampled in coastal North Carolina in 2010 in younger fuels beds of loblolly/longleaf stands near Camp Lejeune (Burling et al., 2011). The emission factors measured in this work differ by ~13-195% to EF measured from the managed stands at Camp Lejeune for organic and N-containing species, suggesting that fire emissions in similar ecosystems can exhibit large variability. Part of the differences, however, may be ascribed to burn conditions as well since the NC burns were during the wet season whereas the SC stands were burned after an extended drought. We also report the first detailed FTIR emissions data for a suite of monoterpenes. Figure 1 displays the emission factors (g/kg fuel) for several monoterpenes and isoprene as measured by the ground-based FTIR system. Due to their unsaturated structure, terpenes are highly reactive compounds emitted from plants thought to contribute to secondary organic aerosol formation (SOA) (Saathoff et al., 2009; Hennigan et al., 2011) and the formation of small oxygenated volatile organic compounds (OVOCs) (Jacob et al., 2002) in fire plumes. The known chemistry and measured abundance of monoterpenes suggests that these species impacted secondary plume processes including ozone, OVOC, and SOA formation in sampled plumes within the first few hours after emission.

biomass burning↗
DOE OSTI2013

Genotypic and phenotypic characterization of aerosolized bacteria collected from African dust events

Twenty-one bacteria were isolated and characterized from air samples collected in Africa and the Caribbean by the United States Geological Survey (USGS). Isolates were selected based on preliminary characterization as possible pathogens. Identification of the bacterial isolates was 25 achieved using 16S rRNA gene sequence analysis, fatty acid methyl esters (FAMEs) profiling, the BIOLOG Microlog® System (carbon substrate assay), and repetitive extragenic palindromic (REP)-PCR analysis. The majority of isolates (18/21) were identified as species of the genus Bacillus. Three isolates were classified within the Bacillus cereus senso lato group, which includes Bacillus anthracis, Bacillus thuringiensis, and Bacillus cereus strains. One isolate was identified as a Staphylococcus sp., 30 most closely related to species (i.e Staphylococcus kloosii, Staphylococcus warneri) that are commonly associated with human or animal skin, but can also act as opportunistic pathogen. Another isolate was tentatively identified as Tsukamurella inchonensis, a known respiratory pathogen, and was resistant to the ten antibiotics tested including vancomycin.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

Production of Xenon-135 from isotopically enriched Xenon-134 and Xenon-136 Targets

Atmospheric radioxenon analyses conducted under the Comprehensive Test Ban Treaty Organization (CTBTO) necessitates the collection and analysis of air samples to quantify 135Xe, an indicator for nuclear explosions and reactor operations. Analytical instrument calibration for these analyses requires high quality, monoisotopic reference standards that are typically short lived, and therefore must be produced and shipped promptly to monitoring stations worldwide. This work describes the preparation of 135Xe by neutron capture (n, ?) on monoisotopic 134Xe, neutron irradiation (n,2n) on monoisotopic 136Xe, and high energy photon irradiation (?, n) on monoisotopic 136Xe. The targets are prepared by electromagnetic isotope separation of natural xenon. Results from each process are compared for 135Xe yield and purity.

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2013

Containment at the Source during Waste Volume Reduction of Large Radioactive Components Using Oxylance High-Temperature Cutting Equipment - 13595

As a waste-volume reduction and management technique, highly contaminated Control Element Drive Mechanism (CEDM) housings were severed from the Reactor Pressure Vessel Head (RPVH) inside the San Onofre Unit 2 primary containment utilizing Oxylance high-temperature cutting equipment and techniques. Presented are relevant data concerning: - Radiological profiles of the RPVH and individual CEDMs; - Design overviews of the engineering controls and the specialized confinement housings; - Utilization of specialized shielding; - Observations of apparent metallurgical-contamination coalescence phenomena at high temperatures resulting in positive control over loose-surface contamination conditions; - General results of radiological and industrial hygiene air sampling and monitoring; - Collective dose and personnel contamination event statistics; - Lessons learned. (author)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Can a radiological event impact a criticality safety program: Lessons learned at WIPP - 14350

Any accident at a nuclear facility impacts all departments involved in the operation of the facility. The radiological release that occurred on February 14, 2014 has halted all waste disposal operations at the Waste Isolation Pilot Plant (WIPP) and has resulted in detailed reviews of all safety management programs. This paper describes the initial reactions to the event, criticality issues with recovery operations, corrective actions for the criticality safety program from independent reviews, and the importance of configuration management to criticality safety. The nature, location, and timing of the event resulted in significant delays in determining the cause of the event. During this time multiple theories on the initiator of the event were postulated including and inadvertent criticality event. However, the timing of the event, average fissile gram equivalent (FGE) loading of waste containers compared to analyzed FGE loads, and isotopic analysis of fixed air samples taken during the event proved it was not an inadvertent criticality event. Recovery activities such as replacing contaminated high efficiency particulate (HEPA), filters and disposing of site generated waste have also been reviewed to prevent criticality safety issues. Post event corrective actions in all departments have impacted how future operations at WIPP will be conducted, including corrective actions for the criticality safety program. The event has also proven the importance of configuration management and the effect a change can have on a process. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS2010

Soyuz 22 Return Samples: Assessment of Air Quality Aboard the International Space Station

Three mini-grab sample containers (m-GSCs) were returned aboard Soyuz 22 because of concerns that new air pollutants were present in the air and these were getting into the water recovery system. The Total Organic Carbon Analyzer had been giving increasing readings of total organic carbon (TOC) in the potable water, and it was postulated that an increased load into the system was responsible. The toxicological assessment of 3 m-GSCs from the ISS is shown in Table 1. The recoveries of the 3 standards (as listed above) from the GSCs averaged 103, 95 and 76%, respectively. Recovery from formaldehyde control badges were 90 and 91%.

Jams, John T.↗
NASA NTRS2011

Soyuz 23 Return Samples: Assessment of Air Quality Aboard the International Space Station

Six mini-grab sample containers (m-GSCs) were returned aboard Soyuz 23 because of concerns that new air pollutants had been present in the air and these were getting into the water recovery system. The Total Organic Carbon Analyzer had been giving increasing readings of total organic carbon (TOC) in the potable water, and it was postulated that an increased load into the system was responsible. The TOC began to decline in late October, 2010. The toxicological assessment of 6 m-GSCs from the ISS is shown in Table 1. The recoveries of 13C-acetone, fluorobenzene, and chlorobenzene from the GSCs averaged 73, 82, and 59%, respectively. We are working to understand the sub-optimal recovery of chlorobenzene.

James, John T.↗
NASA NTRS1993

CITE 3 meteorological highlights

Meteorological highlights from the third NASA Global Tropospheric Experiment Chemical Instrumentation Test and Evaluation (GTE/CITE 3) are presented. During August and September 1989, research flights were conducted from Wallops Island, Virginia, and Natal, Brazil, and included airborne sampling of air masses over adjacent regions of the Atlantic Ocean. Isentropic backward trajectory calculations, wind vector/streamline fields, rawinsonde data, and GOES and METEOSAT satellite imagery are utilized to examine the meteorological conditions for each flight and to determine the transport paths of the sampled air masses. Some aspects of the chemical signatures of the sampled air are also discussed. During the series of flights based at Wallops Island, Virginia, the flow into the experiment area was governed primarily by the position of the North Atlantic subtropical anticyclone. The large-scale tropospheric circulation switched from primarily a marine flow during flights 1-4, to a predominantly offshore mid-latitude continental flow during flights 5-10. During these later flights, the regional influences of large eastern U.S. cities along with vertical mixing by typical summertime convective activity strongly influenced the chemical characteristics of the sampled air. During the series of flights based at Natal, Brazil, the dominant synoptic feature was the South Atlantic subtropical anticyclone which generally transported air across the tropical Atlantic toward eastern Brazil. Pronounced subsidence and a well-defined trade wind inversion often characterized the lower and middle troposphere over the Natal region. Some high-altitude recirculation of air from South America was observed, as was cross-equatorial transport which had come from northern Africa. Biomass burning plumes were observed on segments of all of the flights, the source region being the central and southern savannah regions of Africa.

Shipham, Mark C.↗
DOE OSTI2018

Crystal Structure and Coordination of B-Cations in the Ruddlesden–Popper Phases Sr3−xPrx(Fe1.25Ni0.75)O7−δ (0 ≤ x ≤ 0.4)

Compounds Sr3−xPrxFe1.25Ni0.75O7−δ with 0 ≤ x ≤ 0.4 and Ruddlesden–Popper n = 2 type structures were synthesized and investigated by X-ray and neutron powder diffraction, thermogravimetry, and Mössbauer spectroscopy. Both samples, prepared at 1300 °C under N2(g) flow and samples subsequently air-annealed at 900 °C, were studied. The structures contained oxygen vacancies in the perovskite layers, and the Fe/Ni cations had an average coordination number less than six. The oxygen content was considerably higher for air-annealed samples than for samples prepared under N2, 7 − δ = ~6.6 and ~5.6 per formula unit, respectively. Mössbauer data collected at 7 K, below magnetic ordering temperatures, were consistent with X-ray powder diffraction (XRD) and neutron powder diffraction (NPD) results. The electrical conductivity was considerably higher for the air-annealed samples and was for x = 0.1~30 S·cm−1 at 500 °C. The thermal expansion coefficients were measured in air between room temperature and 900 °C and was found to be 20–24 ppm·K−1 overall.

36 MATERIALS SCIENCE↗
NASA NTRS2011

Soyuz 24 Return Samples: Assessment of Air Quality Aboard the International Space Station

Fifteen mini-grab sample containers (m-GSCs) were returned aboard Soyuz. This is the first time all samples were acquired with the mini-grab samplers. The toxicological assessment of 15 m-GSCs from the ISS is shown. The recoveries of the 3 internal standards, C(13)-acetone, fluorobenzene, and chlorobenzene, from the GSCs averaged 75, 97 and 79%, respectively. Formaldehyde badges were not returned on Soyuz 24

James, John T.↗