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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.

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At least 649 records · Page 36
All sourcesNASA NTRSDOE OSTI
NASA NTRS1977

Evaluation of analytical methodology for hydrocarbons in high pressure air and nitrogen systems

Samples of liquid oxygen, high pressure nitrogen, low pressure nitrogen, and missile grade air were studied to determine the hydrocarbon concentrations. Concentration of the samples was achieved by adsorption on a molecular sieve and activated charcoal. The trapped hydrocarbons were then desorbed and transferred to an analytical column in a gas chromatograph. The sensitivity of the method depends on the volume of gas passed through the adsorbent tubes. The value of the method was verified through recoverability and reproducibility studies. The use of this method enables LOX, GN2, and missile grade air systems to be routinely monitored to determine low level increases in specific hydrocarbon concentration that could lead to potentially hazardous conditions.

Source record↗
DOE OSTI2014

Morphological classification of bioaerosols from composting using scanning electron microscopy

Highlights: • Bioaerosols were captured using the filter method. • Bioaerosols were analysed using scanning electron microscope. • Bioaerosols were classified on the basis of morphology. • Single small cells were found more frequently than aggregates and larger cells. • Smaller cells may disperse further than heavier aggregate structures. - Abstract: This research classifies the physical morphology (form and structure) of bioaerosols emitted from open windrow composting. Aggregation state, shape and size of the particles captured are reported alongside the implications for bioaerosol dispersal after release. Bioaerosol sampling took place at a composting facility using personal air filter samplers. Samples were analysed using scanning electron microscopy. Particles were released mainly as small (<1 μm) single, spherical cells, followed by larger (>1 μm) single cells, with aggregates occurring in smaller proportions. Most aggregates consisted of clusters of 2–3 particles as opposed to chains, and were <10 μm in size. No cells were attached to soil debris or wood particles. These small single cells or small aggregates are more likely to disperse further downwind from source, and cell viability may be reduced due to increased exposure to environmental factors.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS2007

A Side by Side Comparison of Filter-Based PM(sub 2.5) Measurements at a Suburban Site: A Closure Study

Reliable determination of the effects of air quality on public health and the environment requires accurate measurement of PM(sub 2.5) mass and the individual chemical components of fine aerosols. This study seeks to evaluate PM(sub 2.5) measurements that are part of a newly established national network by comparing them with a more conventional sampling system. Experiments were carried out during 2002 at a suburban site in Maryland, United States, where two samplers from the U.S. Environmental Protection Agency (USEPA) Speciation Trends Network: Met One Speciation Air Sampling System STNS and Thermo Scientific Reference Ambient Air Sampler STNR, two Desert Research Institute Sequential Filter Samplers DRIF, and a continuous TEOM monitor (Thermo Scientific Tapered Element Oscillating Microbalance) were sampling air in parallel. These monitors differ not only in sampling configuration but also in protocol-specific sample analysis procedures. Measurements of PM(sub 2.5) mass and major contributing species were well correlated among the different methods with r-values > 0.8. Despite the good correlations, daily concentrations of PM(sub 2.5) mass and major contributing species were significantly different at the 95% confidence level from 5 to 100% of the time. Larger values of PM(sub 2.5) mass and individual species were generally reported from STNR and STNS. The January STNR average PM(sub 2.5) mass (8.8 (micro)g/per cubic meter) was 1.5 (micro)g/per cubic meter larger than the DRIF average mass. The July STNS average PM(sub 2.5) mass (27.8 (micro)g/per cubic meter) was 3.8 (micro)g/per cubic meter larger than the DRIF average mass. These differences can only be partially accounted for by known random errors. Variations in flow control, face velocity, and sampling artifacts likely influence the measurement of PM(sub 2.5) speciation and mass closure. Simple statistical tests indicate that the current uncertainty estimates used in the STN network may underestimate the actual uncertainty.

Haines, Jennifer C.↗
DOE OSTI2019

Effect of Sintering Atmosphere on the Synthesis Process, Electrical and Mechanical Properties of NiFe{sub 2}O{sub 4}/Nano-TiN Ceramics

NiFe{sub 2}O{sub 4}/nano-TiN ceramics were fabricated by a two-step cold-pressing sintering process. Effect of sintering atmosphere (air, nitrogen, argon) on the synthesis process of NiFe{sub 2}O{sub 4}/nano-TiN ceramics was investigated. The DSC-TG and XRD analysis results indicated that besides principal phases of NiO and NiFe{sub 2}O{sub 4}, new-phase Ni{sub 3}TiO{sub 5} formed in the sintered ceramics under the three sintering atmospheres, and metallic phase including iron and nickel appeared in the sintered samples with inert gas (nitrogen, argon) sintering condition. Microstructure analysis results showed that considerable quantity of micropores appeared in the ceramic samples sintered under inert gases (argon, nitrogen), but lower porosity (3.0, 3.6%) and higher densities (4.78 g/cm{sup 3}, 4.51 g/cm{sup 3}) can be obtained, comparing to the both values (14.4%, 4.17 g/cm{sup 3}) for the ceramic samples sintered under air atmosphere. Besides, the average bending strength and elastic modulus of the samples sintered under argon is 113.75 MPa and 7.13GPa, which is higher than that of 75.12 MPa, 5.42GPa and 91.96 MPa, 6.26GPa for the samples synthesized under air and nitrogen, separately. When changing sintering atmosphere from air to inert gases (argon, nitrogen), the fracture model of the 4 wt.%nano-TiN/NiFe{sub 2}O{sub 4} ceramics synthesized at 1400 °C for 4 h transformed from intergranular fracture to intergranular-transgranular fracture.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Counterflow Virtual Impactor (CVI) Inlet Aboard Aircraft (INLETCVI-AIR) Instrument Handbook

The counterflow virtual impactor (CVI) inlet separates out and samples cloud elements via inertial impaction. Warm, dry, particle-free carrier gas of known composition is pumped to the tip of the inlet in the direction opposite of the flow of air. The flow lines of the incoming free stream air are split. Larger droplets and ice crystals suspended in the sample air have enough inertia to penetrate the counterflow and enter the sample flow, while smaller, unactivated particles follow the streamlines of the air flowing around the inlet’s tip (Noone et al. 1988). The instrument is capable of sampling cloud elements as a function of cut size by changing the velocity of counterflow at the probe tip. The CVI cut size is usually defined as a diameter of a smallest particle for which penetration rate is 50%. For the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) user facilityGulfstream-159 aircraft’s CVI inlet, that value is usually around 13 microns. The dry heated air, normally used as the carrier gas, also serves to evaporate water from the hydrometeor, leaving the residuals to be sampled by in-cabin aerosol instrumentation. The number concentration of the droplet residue in the CVI sample line is usually increased with respect to corresponding cloud element number concentration. The CVI performance as a concentrator is usually described via CVI enhancement factor, which is a conversion factor between ambient volumetric concentration (not adjusted to standard temperature and pressure) and volumetric concentration in the CVI sample line.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS1979

Effect of degree of fuel vaporization on emissions for a premixed-prevaporized combustor system

The impact of the degree of fuel vaporization upon emission from a flametube combustor was studied using an inlet air pressure of 3 x 10 to the 5th power pascals, inlet air temperatures of 600K and 700K, a reference velocity of 35 meters per second and equivalence ratios of .6 and .72 using Jet A fuel. Incoming air was preheated to temperatures from 600K to 700K by a nonvitiating preheater. Jet A fuel was injected into this airstream through two different fuel injectors manifolded together and mounted in series upstream of a watercooled preforated plate flameholder. The fuel-air mixture burned in a watercooled combustor section. Samples of the fuel-air mixture upstream of the flameholder were obtained for analysis to determine the local degree of fuel vaporization and the fuel-air ratio. Samples of the combustion products were analyzed to determine gaseous emissions. The effects of vaporization on carbon monoxide and nitric on carbon monoxide and nitric oxide emissions are presented.

Cooper, L. P.↗
DOE OSTI2012

The iSERIES™ radon progeny compensation algorithm and its application to air filters

Sandia has developed methods to perform a rapid count using Canberra’s iSERIES™ Alpha/Beta Counting System, the iSOLO™. The purpose of this report is to show that by using the iSERIES™ built-in radon progeny compensation algorithm, the radon progeny-free gross alpha air concentration can be determined for a sample taken using a high volume air sampler or a lapel device within a few hours post-sampling. Also, a special form of the Currie Minimum Detectable Activity estimation was derived for use with the radon progeny stripping algorithm after it was discovered that the expression used by the Canberra software did not take the counts due to radon progeny into consideration as part of the background. This rapid air sample analysis proves to be a vast improvement to the current method that has an average turn-around time between seven and ten days.

Fournier, Sean Donovan↗
NASA NTRS2016

Contaminant Permeation in the Ionomer-Membrane Water Processor (IWP) System

The Ionomer-membrane Water Processor (IWP) is a patented membrane-distillation based urine brine water recovery system. The unique properties of the IWP membrane pair limit contaminant permeation from the brine to the recovered water and purge gas. A paper study was conducted to predict volatile trace contaminant permeation in the IWP system. Testing of a large-scale IWP Engineering Development Unit (EDU) with urine brine pretreated with the International Space Station (ISS) pretreatment formulation was then conducted to collect air and water samples for quality analysis. Distillate water quality and purge air GC-MS results are presented and compared to predictions, along with implications for the IWP brine processing system.

Kelsey, Laura K.↗
DOE OSTI2022

Short communication: Mechanism and prevention of irreversible trapping of atmospheric He during mineral crushing

A pervasive challenge in noble gas geochemistry is to ensure that analytical techniques do not modify the composition of the noble gases in the samples. Noble gases are present in the atmosphere and are used in a number of manufacturing procedures and by laboratory equipment. Of particular concern is the introduction of atmospheric or laboratory noble gases to samples during preparation before samples are placed in a vacuum chamber for analysis. Recent work has shown the potential for contamination of crushed samples with air-derived He that is not released by placing the samples under vacuum at room temperature. Using pure He gas as a tracer, we show that the act of crushing samples to a fine powder itself can introduce He contamination but that this is easily avoided by crushing under liquid or in an inert atmosphere. Because the He is trapped during crushing, the same concern does not extend to samples that are naturally fine-grained when collected. We also show model results that demonstrate when this effect might significantly impact samples for (U–Th) / He geochronology or 3 He cosmogenic nuclide dating. The degree of He contamination from crushing samples to sizes smaller than the > 63 µm range typically used for geochronology is insignificant for samples with a date of at least 1 Ma and 1 ppm U, and the degree of He contamination from crushing samples to sizes smaller than the 100–500 µm range typically used for cosmogenic nuclide dating is also insignificant for samples with a date of at least 10 ka with typical 3 He production rates.

58 GEOSCIENCES↗
DOE OSTI2021

Magnetism in Mixed Valence, Defect, Cubic Perovskites: BaIn 1– x Fe x O 2.5+δ , x = 0.25, 0.50, and 0.75. Local and Average Structures

The series BaIn 1–x Fe x O 2.5+δ , x = 0.25, 0.50, and 0.75, has been prepared under air-fired and argon-fired conditions and studied using X-ray diffraction, d.c. and a.c. susceptibility, Mössbauer spectroscopy, neutron diffraction, X-ray near edge absorption spectroscopy (XANES), and X-ray pair distribution (PDF) methods. While Ba 2 In 2 O 5 (BaInO 2.5 ) crystallizes in an ordered brownmillerite structure, Ibm2, and Ba 2 Fe 2 O 5 (BaFeO 2.5 ) crystallizes in a complex monoclinic structure, P2 1 /c, showing seven Fe 3+ sites with tetrahedral, square planar, and octahedral environments, all phases studied here crystallize in the cubic perovskite structure, Pm$\bar{}3}$m, with long-range disorder on the small cation and oxygen sites. 57 Fe Mössbauer studies indicate a mixed valency, Fe 4+ /Fe 3+ , for both the air-fired and argon-fired samples. The increased Fe 3+ content for the argon-fired samples is reflected in increased cubic cell constants and in the increased Mössbauer fraction. It appears that the Pm$\bar{}3}$m phases are only metastable when fired in argon. From a slightly modified percolation theory for a primitive cubic lattice (taking into account the presence of random O atom vacancies), long-range spin order is permitted for the x = 0.50 and 0.75 phases. Instead, the d.c. susceptibility shows only zero-field-cooled (ZFC) and field-cooled (FC) divergences at ~6 K [5 K] for x = 0.50 and at ~22 K [21 K] for x = 0.75, with values for the argon-fired samples in [ ]. Neutron diffraction data for the air-fired samples confirm the absence of long-range magnetic order at any studied temperature. For the air-fired x = 0.50, a.c. susceptibility data show a frequency-dependent χ'(max) and spin glass behavior, while for x = 0.75, χ'(max) is invariant with frequency, ruling out either a spin glass or a superparamagnetic ground state. These behaviors are discussed in terms of competing Fe 3+ –Fe 3+ antiferromagnetic exchange and ferromagnetic Fe 3+ –Fe 4+ exchange. The PDF and 57 Fe Mössbauer data indicate a local structure at short interatomic distances, which deviates strongly from the average Pm$\bar{}3}$m model. Fe Mössbauer, PDF, and XANES data show a systematic dependence on x and indicate that the Fe 3+ sites are largely fourfold-coordinated and Fe 4+ sites are fivefold- or sixfold-coordinated.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1982

Properties of a constricted-tube air-flow levitator

The properties of a constricted-tube gas flow levitator first developed by Berge et al. (1981) have been investigated experimentally in order to predict its behavior in a gravity-free environment and at elevated temperatures. The levitator consists of a constricted (quartz) tube fed at one end by a source of heated air or gas. A spherical sample is positioned by the air stream on the downstream side of the constriction, where it can be melted and resolidified without touching the tube. It is shown experimentally that the kinematic viscosity is the important fluid parameter for operation in thermal equilibrium at high temperatures. If air is heated from room temperature to 1200 C, the kinematic viscosity increases by a factor of 14. To maintain a given value of the Reynolds number, the flow rate would have to be increased by the same factor for a specific geometry of tube and sample. Thus, to maintain stable equilibrium, the flow rate should be increased as the air or other gas is heated. The other stability problem discussed is associated with changes in the shape of a cylindrical sample as it melts.

Rush, J. E.↗
DOE OSTI2022

Citizen Green #1 Well: Quantitative XRD & Thin Section Data

This submission includes information on quantitative x-ray diffraction measurements and thin section photography conducted on sidewall cores from the Citizen Green #1 well drilled on King Island, CA (API 07720688) as part of the WESTCARB partnership basin characterization effort. Cores were acquired with a rotary sidewall tool at a range of depths; only deeper cores were sufficiently consolidated for analysis. SidewallCoreFormationDepthNotes.xls provides details on available samples. Helium porosimetry, air permeability, and brine permeability measurements were conducted on all competent samples (~15). Samples were largely in the Mokelumne, H&T shale, and Starkey formations. All measurements were conducted at Lawrence Berkeley National Laboratory.

Thin Section↗
DOE OSTI2023

Citizen Green #1 Well : Sidewall Core Permeability Studies

This submission includes information on porosity & permeability measurements conducted on sidewall cores from the Citizen Green #1 well drilled on King Island, CA (API 07720688) as part of the WESTCARB partnership basin characterization effort. Cores were acquired with a rotary sidewall tool at a range of depths; only deeper cores were sufficiently consolidated for analysis. SidewallCoreFormationDepthNotes.xls provides details on available samples. Helium porosimetry, air permeability, and brine permeability measurements were conducted on all competent samples (~15). Samples were largely in the Mokelumne, H&T shale, and Starkey formations. All measurements were conducted by Core Laboratories (Bakersfield) on behalf of Lawrence Berkeley National Laboratory (LBNL) with final reports provided in November of 2012. Further measurements were conducted on some sidewalls with data in other submissions.

pemeability↗
NASA NTRS1991

Investigation of the effect of thermal exposure on the mechanical properties of titanium/SiC composites

The objective was to evaluate the influence of thermal exposure, both isothermal and cyclic, on the reaction kinetics, mechanical properties and fracture behavior of Ti-1100 alloy/SiC fiber composites. Previously, it was determined that composites made with TiB2 coated SiC fiber (sigma) reacted at the same rate as SCS-6 fibers. As a result, the thinner surface coating on the Sigma fiber was completely consumed at shorter times than that on the SCS-6. Thermal cycling experiments were conducted on longitudinal and transverse Ti-1100/SCS-6 composites over a temperature range of 150 to 800 C for 500 cycles. The thermal exposures were carried out in air and argon. No appreciable tensile strength degradation was observed for samples cycled in argon, although a strength loss was noted for the samples cycled in air. Fracture surfaces characterization showed brittle matrix failure in regions near the surface and in regions where there was a path for O2 ingress.

Gundel, Douglas B.↗
NASA NTRS2005

Microbial Air and Surface Monitoring Results from International Space Station Samples

Over the course of long-duration spaceflight, spacecraft develop a microbial ecology that directly interacts with the crew of the vehicle. While most microorganisms are harmless or beneficial to the inhabitants of the vehicle, the presence of medically significant organisms appearing in this semi-closed environment could adversely affect crew health and performance. The risk of exposure of the crew to medically significant organisms during a mission is estimated using information gathered during nominal and contingency environmental monitoring. Analysis of the air and surface microbiota in the habitable compartments of the International Space Station (ISS) over the last four years indicate a high presence of Staphylococcus species reflecting the human inhabitants of the vehicle. Generally, air and surface microbial concentrations are below system design specifications, suggesting a lower risk of contact infection or biodegradation. An evaluation of sample frequency indicates a decrease in the identification of new species, suggesting a lower potential for unknown microorganisms to be identified. However, the opportunistic pathogen, Staphylococcus aureus, has been identified in 3 of the last 5 air samples and 5 of the last 9 surface samples. In addition, 47% of the coagulase negative Staphylococcus species that were isolated from the crew, ISS, and its hardware were found to be methicillin resistance. In combination, these observations suggest the potential of methicillin resistant infectious agents over time.

Ott, C. Mark↗
DOE OSTI2014

Iodine solubility in a low-activity waste borosilicate glass at 1000°C

The purpose of this study was to determine the solubility of iodine in a low-activity waste borosilicate glass when heated inside an evacuated and sealed fused quartz ampoule. The iodine was added to glass frit as KI in quantities of 100–24000 ppm iodine (by mass), each mixture was added to an ampoule, the ampoules were heated at 1000 °C for 2h, and then air quenched. In samples with ≥12000 ppm iodine, low viscosity salt phases were observed on the surface of the melts during cooling that solidified into a white coating upon cooling. These salts were identified as mixtures of KI, NaI, and Na 2 SO 4 with X-ray diffraction (XRD). The iodine concentrations in glass specimens were analyzed with inductively-coupled plasma mass spectrometry and the overall iodine solubility was determined to be 10000 ppm by mass. Several crystalline inclusions of iodine sodalite, Na 8 (AlSiO 4 ) 6 I 2 , were observed in the 24000 ppm specimen as determined by micro-XRD and wavelength dispersive spectroscopy.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRSDate not supplied

Field Geologic Mapping of Sample Sites From the Ground and the Air With Perseverance Rover and Ingenuity Helicopter

One of the primary mission goals for Perseverance is to determine the geologic context of sample sites. Rover-based (in situ) or field geologic context mapping (GXM) based on Perseverance rover and Ingenuity helicopter observations provides a nearly continuous record of geologic context and exposed surface structure over a 120 m-wide corridor along the traverse of Perseverance and the flight path of Ingenuity. Field geologic mapping along the traverse and flight path and outcrop-scale mapping at sample sites provides a spatial dimension to ground truth geologic, stratigraphic, and modern environmental context for samples at scales relevant to sample interpretation. Here we provide an abbreviated overview of field mapping as it relates to documenting the architecture of the Jezero fan and geologic context of several examples of sample locations.

Mars 2020↗
DOE OSTI2019

Hanford SMART System: Calculation of Radionuclide Emissions, Ambient Air Concentrations and Error Propagation (Final Report)

This document, authored by Radiological Assessment Corporation (RAC), details the calculations used to convert laboratory radiological analytical sample data and field measurement data for both ambient air samplers and stack air samples to concentration values with associated uncertainty. The RAC supported an effort by Mission Support Alliance (MSA) to replace the Automated Bar Coding of All Samples at Hanford (ABCASH) and Environmental Release Summary (ERS) database software with a commercial off-the-shelf (COTS) data management software system. The ABCASH and ERS databases were not compatible with the Hanford system standards Windows 10 Operating System deployed in calendar year 2018. The replacement software, Sample Management and Analytical Results Tracking (SMART), is used for environmental data collection, analyses, and regulatory reporting for the Hanford Environmental Surveillance and Effluent Monitoring programs.

54 ENVIRONMENTAL SCIENCES↗