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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 307 records · Page 17
All sourcesNASA NTRSDOE OSTI
NASA NTRS2024

NESC Ceramic Oxygen Generator (COG) Technology Development

The NASA Engineering and Safety Center (NESC) sponsored a project to accelerate the pace of technology development of a ceramic oxygen generator (COG), for NASA and COVID related medical use. NASA applications for this technology include spacesuit oxygen tank recharge, medical applications include providing medical oxygen in remote and low resource settings. During this project, five full-scale (i.e., 30 wafer) cell stacks were built and tested in prototype systems capable of producing pressurized oxygen. System testing measured oxygen product purity, delivery pressure, production rate, and energy use. This report describes ion transport membrane mechanisms, cell stack configuration, and test results.

Oxygen↗
NASA NTRS1993

Oxygen Tracer Diffusion in LA(z-x) SR(X) CUO(4-y) Single Crystals

The tracer diffusion of O-18 in La(2-x)Sr(x)CuO(4-y) single crystals (x = 0 to 0.12) has been measured from 400 to 700 C in 1 atm of oxygen using SIMS analysis. Evidence for diffusion by a vacancy mechanism was found at low strontium contents. Oxygen diffusivities for x greater than or = 0.07 were depressed by several orders of magnitude below the diffusivity for undoped La2CuO(4+/-y). The observed effects of strontium doping on oxygen diffusivity are discussed in terms of defect chemical models. The decreasing oxygen diffusivity with increasing strontium was attributed to the ordering of oxygen vacancies at large defect concentrations. A diffusion anisotropy D(sub ab)/D(sub c) of nearly 600 was also found at 500 C.

OXYGEN DIFFUSIVITY↗
NASA NTRS1994

Intelsat solar array coupon atomic oxygen flight experiment

A Hughes communications satellite (INTELSAT series) belonging to the INTELSAT Organization was marooned in low-Earth orbit (LEO) on March 14, 1990, following failure of the Titan launch vehicle third stage to separate properly. The satellite, INTELSAT 6, was designed for service in geosynchronous orbit and contains several materials that are potentially susceptible to attack by atomic oxygen. Analysis showed that direct exposure of the silver interconnects in the satellite photovoltaic array to atomic oxygen in LEO was the key materials issue. Available data on atomic oxygen degradation of silver are limited and show high variance, so solar array configurations of the INTELSAT 6 type and individual interconnects were tested in ground-based facilities and during STS-41 (Space Shuttle Discovery, October 1990) as part of the ISAC flight experiment. Several materials for which little or no flight data exist were also tested for atomic oxygen reactivity. Dry lubricants, elastomers, and polymeric and inorganic materials were exposed to an oxygen atom fluence of 1.1 x 10(exp 20) atoms cm(exp 2). Many of the samples were selected to support Space Station Freedom design and decision making. This paper provides an overview of the ISAC flight experiment and a brief summary of results. In addition to new data on materials not before flown, ISAC provided data supporting the decision to rescue INTELSAT 6, which was successfully undertaken in May 1992.

TRT-GENERAL REVIEW↗
NASA NTRS2013

Photoionization Modeling of Oxygen K Absorption in the Interstellar Medium:

We present detailed analyses of oxygen K absorption in the interstellar medium (ISM) using four high-resolution Chandra spectra toward the X-ray low-mass binary XTE J1817-330. The 11-25 Angstrom broadband is described with a simple absorption model that takes into account the pile-up effect and results in an estimate of the hydrogen column density. The oxygen K-edge region (21-25 Angstroms) is fitted with the physical warmabs model, which is based on a photoionization model grid generated with the xstar code with the most up-to-date atomic database. This approach allows a benchmark of the atomic data which involves wavelength shifts of both the K lines and photoionization cross sections in order to fit the observed spectra accurately. As a result we obtain a column density of N(sub H) = 1.38 +/- 0.01 × 10(exp 21) cm(exp −2); an ionization parameter of log xi = −2.70 +/- 0.023; an oxygen abundance of A(sub O) = 0.689 (+0.015/−0.010); and ionization fractions of O(sub I)/O = 0.911, O(sub II)/O = 0.077, and O(sub III)/O = 0.012 that are in good agreement with results from previous studies. Since the oxygen abundance in warmabs is given relative to the solar standard of Grevesse & Sauval, a rescaling with the revision by Asplund et al. yields A(sub O) = 0.952(+0.020/−0.013), a value close to solar that reinforces the new standard.We identify several atomic absorption lines-K(alpha), K(beta), and K(gamma) in O(sub I) and O(sub II) and K(alpha) in O(sub III), O(sub VI), and O(sub VII)-the last two probably residing in the neighborhood of the source rather than in the ISM. This is the first firm detection of oxygen K resonances with principal quantum numbers n greater than 2 associated with ISM cold absorption.

oxygen↗
NASA NTRS2016

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

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.

Oxygen recovery↗
NASA NTRS2016

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

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.

ECLSS↗
NASA NTRS2016

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

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.

Oxygen Recovery↗
NASA NTRSDate not supplied

Atomic Oxygen Environment and Effects Overview

Atomic oxygen is the most predominant constituent in the low Earth orbital environment between the altitudes of 180 and 650 km. It is also a major constituent of the Mars orbital environment. It is very chemically reactive and can oxidize many spacecraft surfaces to form volatile reaction products. The importance of understanding atomic oxygen reactions with materials has led to both flight experiments in low Earth orbit and ground-based testing in vacuum chambers containing atomic oxygen to study its’ effect on materials. Testing has been performed in order to determine the extent of the atomic oxygen reaction and assess material and component durability. In addition, the effectiveness of mitigation techniques such as application of a protective coating, adding fillers, or using shielding and getter materials has also been studied both in flight and ground-based experiments. This presentation will focus on defining atomic oxygen environments, discussing its effect on spacecraft materials, and describing some of the testing and mitigation techniques that have been investigated.

Atomic Oxygen, Low Earth Orbit, Low Mars Orbit, ox↗
NASA NTRS2024

Grossite-Bearing Refractory Inclusions from Reduced CV Chondrites: Mineralogical and Oxygen Isotopic Constraints on the Parent Body Alteration History

We report the results of coordinated mineralogical, microstructural, and oxygen isotopic analyses of grossite-bearing refractory inclusions from reduced CV (Vigarano type) chondrites to obtain a more complete picture of secondary parent body alteration processes and conditions. Grossite (CaAl 4 O 7 ) occurs in cores of nodules in fine-grained Ca,Al-rich inclusions (CAIs) that likely represent aggregates of nebular condensates. In many occurrences, grossite has been partially replaced by hercynite [(Fe,Mg,Zn)Al 2 O 4 ], which displays complex microstructures and compositions, and magnetite nanoparticles. The alteration of grossite was a crystallographically-controlled, fluid-driven process that occurred via partial dissolution of grossite and subsequent precipitation of hercynite and magnetite during short-lived and low-temperature metasomatic alteration on the CV chondrite parent body. The constituent phases of grossite-bearing CAIs show heterogeneous oxygen isotopic compositions, with grossite and perovskite displaying systematically 16O-depleted compositions (Δ 17 O = −12‰ to −1‰) relative to uniformly 16 O-rich hibonite and spinel (Δ 17 O = −25‰ to −21‰). Melilite is variably 16 O-depleted (Δ 17 O = −25‰ to −2‰). The observed oxygen isotopic distribution is interpreted as a result of mineralogically controlled oxygen isotopic exchange with an 16 O-poor fluid on the CV chondrite parent body. Collectively, the presence of limited fluids played an important role in preferential alteration of grossite to hercynite and magnetite and various degrees of 16O depletion in grossite, perovskite, and melilite during thermal metamorphism. We conclude that, among refractory phases in the inclusions, grossite was the most susceptible to metasomatic reactions with Fe-rich fluids and the second most susceptible, after perovskite, to oxygen isotopic exchange with an 16 O-poor fluid during the thermal history of the CV chondrite parent asteroid.

Calcium-aluminum-rich inclusions↗
NASA NTRS1971

Research on rechargeable oxygen electrodes

Studies were carried out on a number of factors which may influence the behavior of the platinum electrocatalyst of oxygen electrodes for use in rechargeable metal-oxygen batteries or hydrogen-oxygen fuel cells. The effects of pretreatments for various potentials and added ionic species, which could be present in such systems, were studied with reguard to: (1) the state of surface oxidation, (2) platinum dissolution, (3) the kinetics of oxygen evolution and reduction (including the role of hydrogen peroxide), and (4) changes in porous electrode structure. These studies were carried out on smooth platinum, platinized platinum, and Teflon-bonded platinum black electrodes in carefully purified electrolyte solutions. The main factors which appear to affect rechargeable oxygen electrode performance and life are: (1) the buildup of a refractory anodic layer on extended cycling, and (2) the dissolution of platinum.

Giner, J.↗
NASA NTRS1972

Thin film oxygen partial pressure sensor

The development is described of a laboratory model oxygen partial pressure sensor using a sputtered zinc oxide thin film. The film is operated at about 400 C through the use of a miniature silicon bar. Because of the unique resistance versus temperature relation of the silicon bar, control of the operational temperature is achieved by controlling the resistance. A circuit for accomplishing this is described. The response of sputtered zinc oxide films of various thicknesses to oxygen, nitrogen, argon, carbon dioxide, and water vapor caused a change in the film resistance. Over a large range, film conductance varied approximately as the square root of the oxygen partial pressure. The presence of water vapor in the gas stream caused a shift in the film conductance at a given oxygen partial pressure. A theoretical model is presented to explain the characteristic features of the zinc oxide response to oxygen.

Wortman, J. J.↗
NASA NTRS1971

Effect of circadian rhythm on CNS oxygen toxicity.

The circadian rhythm in susceptibility to oxygen toxicity seizures was investigated by using six groups of 20 male Sprague-Dawley rats (101-196 gm.). The animals were given standard chow, exposed to standard diurnal conditions of light (0700-1900 hr) and dark (1900-0700 hr), and fasted for 15-16 hr prior to exposure to hyperbaric oxygen. The animals were placed in a previously oxygen flushed chamber and raised to 60 psi (gauge) oxygen at a rate of 3 psi/min. Time of exposure started with attainment of 60 psi. End point was first convulsion. The animals' weights were equally distributed within the groups, and the groups were defined by hour of exposure. Time of exposure in minutes prior to seizure was significantly longer in those exposed at 0700-0800 hr and 1000-1100 hr than in four other groups. There was no relationship between animals' weights and time of exposure to seizures. All R values were negative, and the highest R value was -035. These data suggest a definite circadian rhythm in susceptibility to oxygen toxicity seizures.

Hof, D. G.↗
NASA NTRS1972

Catalysts for initiating the hydrogen-oxygen reaction at 78 K.

Catalysts for initiating reaction of hydrogen with oxygen in gas mixtures at temperatures down to 78 K (-195 C) were sought. A rising-temperature reactor was used for detecting onset of reaction. The platinum metals, especially iridium, platinum, and ruthenium, were the most active. With high concentrations of iridium on an alumina support, reaction initiation was observed at -195 C for a helium stream containing 3% hydrogen and 1% oxygen. Best results were obtained when the catalyst had been preheated in hydrogen and cooled in a hydrogen environment before being contacted with oxygen-containing gas. The initiation is interpreted to be the result of transient phenomena which occur when a hydrogen-oxygen mixture contacts an active catalyst. Chemisorption of oxygen and formation of some water, along with water adsorption on the support, serve to raise the temperature to a point where true catalysis can proceed.

Jennings, T. J.↗
NASA NTRS1972

ASRDI oxygen technology survey. Volume 3: Heat transfer and fluid dynamics. Abstracts of selected technical reports and publications

Selected information is presented from an assemblage of reports and publications on heat transfer and fluid dynamics with direct applicability to oxygen systems. For each document cited, an abstract has been prepared together with key words and a listing of most important references found in the document. Additionally, an author index, a subject index, and a key word index have been provided to simplify the retrieval of specific information from this work. In each subject area - e.g., boiling heat transfer - the individual citations are listed alphabetically by first author, with review papers dually noted under the appropriate subject category and under review papers. Of the documents reviewed and evaluated for inclusion in this publication, coverage of existing information directly concerned with oxygen was given primary emphasis. However, work not specifically oxygen-designated but considered applicable to oxygen by the reviewer e.g., a two-phase friction factor correlation derived from nitrogen experiments is occasionally given where no actual oxygen data exist, as an aid to the reader. Approximately 130 abstracts are listed.

Schmidt, A. F.↗
NASA NTRS1973

High pressure oxygen utilization by NASA.

The conditions of use of oxygen by NASA are severe, since moving liquid oxygen at the rates required by large rocket engines calls for high pressures and high flow velocities. NASA also has requirements for gaseous oxygen systems that operate at pressures above the range of industrial practice. Some of the facts pointing up the need for improved criteria for oxygen handling, and work within NASA aimed at developing them are reviewed. Research on oxygen compatibility at high pressure is described. It is shown that the degradation of mechanical properties, the susceptibility to ignition by various stimuli, and the resistance to burning must be quantitatively defined.

Belles, F. E.↗
NASA NTRS1973

Loss of atomic oxygen in mass spectrometer ion sources.

A gas beam consisting of a mixture of atomic and molecular oxygen has been directed at the ion source of a mass spectrometer like those used in sounding rockets for determining the neutral composition of the lower thermosphere. The loss of atomic oxygen on mass spectrometer surfaces was evaluated by flagging the beam in several ways and comparing the experimental results with predicted values. The results obtained suggest that in rocket flights using similar instruments the atomic oxygen densities computed assuming no-loss conditions may be low by a factor of 2.5. Studies made using a beam containing tracer O-18 indicate that carbon dioxide observed when atomic oxygen enters the source is formed in a reaction involving atomic oxygen from the beam and carbon monoxide from the surfaces bombarded.

Lake, L. R.↗
NASA NTRS1973

Narcosis studies and oxygen poisoning of mice

The research for a mechanism by which narcotic gases alter metabolism is reported. Possible sites of action by narcotic and anesthetic gases in isolated electron transport particles were explored. Using the relative activities of the NADH-oxygen, NADH-ferricyanide, succinate-cytochrome C and succinate-NAD oxidoreductase systems as parameters, the relative potency of volatile anesthetics were tested. Testing the relative ability of human subjects to contract and repay an oxygen debt while in the narcotic versus alert state, it was found that narcosis induced by 33% nitrous oxide increased the size of the oxygen debt contracted and the amount of oxygen required to repay it during recovery. Mice acclimatized to sea level (760 mm Hg), 5000 feet (632 mm Hg) or 15,000 feet 437 mm Hg) for from one to eight weeks were found to be more susceptible to convulsion and death as a function of altitude acclimatization when tested in hyperoxic environments. There were no reasonable explanations for the connection between hypoxia and oxygen poisoning but several practical implications for persons living at altitude are discussed.

Source record↗
NASA NTRS1973

Blood flow and oxygen uptake during exercise

A model is developed for predicting oxygen uptake, muscle blood flow, and blood chemistry changes under exercise conditions. In this model, the working muscle mass system is analyzed. The conservation of matter principle is applied to the oxygen in a unit mass of working muscle under transient exercise conditions. This principle is used to relate the inflow of oxygen carried with the blood to the outflow carried with blood, the rate of change of oxygen stored in the muscle myoglobin, and the uptake by the muscle. Standard blood chemistry relations are incorporated to evaluate venous levels of oxygen, pH, and carbon dioxide.

Mitchell, J. W.↗