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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 577 records · Page 32
All sourcesNASA NTRSDOE OSTI
NASA NTRS1977

Study of coatings for improved fire and decay resistance of mine timbers

The purpose of this program was to find a fire- and rot-retardant polymer/fungicide reaction product for coating mine timbers. Fire-retardant polymers were screened as films and coatings on fir wood. Curable polyimide appeared to be flame retardant and evolved a minimum of fumes when exposed to a flame. Several organic and metal, low toxicity, fungicides were reacted with the polyimide in-situ on the wood. These coated samples were screened for fungus resistance. All formulations rated well - even the polyimide film without additives was fungicidal. The fir wood control itself resisted internal damage during the ten weeks of fungus exposure. A more severe test for fungus resistance will be required.

Baum, B.↗
NASA NTRS1977

Soil, water, and vegetation conditions in south Texas

The author has identified the following significant results. The best wavelengths in the 0.4 to 2.5 micron interval were determined for detecting lead toxicity and ozone damage, distinguishing succulent from woody species, and detecting silverleaf sunflower. A perpendicular vegetation index, a measure of the distance from the soil background line, in MSS 5 and MSS 7 data space, of pixels containing vegetation was developed and tested as an indicator of vegetation development and crop vigor. A table lookup procedure was devised that permits rapid identification of soil background and green biomass or phenological development in LANDSAT scenes without the need for training data.

Wiegand, C. L.↗
NASA NTRS1977

Response of Selected Microorganisms to Experimental Planetary Environments

Results of studies in anaerobic phosphorus metabolism are presented. Specific topics discussed include: (1) anaerobic utilization of PH3; (2) reduction of phosphate or phosphite; (3) isolation of organisms which utilize phosphite or phosphate anaerobically as a final hydrogen acceptor; and (4) the toxicity of PH3 to the organisms. Techniques of anaerobic microbiology associated with space hardware were also studied. These include: (1) the Brewer anaerobe jar/GasPak system; (2) a new procedure to grow aerobes and anaerobes simultaneously; (3) a culture medium to differentiate oblagate from facultative anaerobes; and (4) a procedure to quantitate O2 sensitivity of anaerobes.

Foster, T. L.↗
NASA NTRS1975

Environmental health trends

Trends in environmental health listed include: specific health concerns, sources of organic dusts causing pneumonitis, toxic substances lists, criteria documents, and regulatory developments.

Proctor, G.↗
NASA NTRS1975

Concepts in health evaluation of commercial and industrial chemicals

A method is described for determining no toxic effect exposure levels based on short-term testing of industrial and commercial chemicals. Procedures for monitoring all organs and body functions for the presence or absence of toxicological effects are demonstrated using various laboratory animals.

Mcnamara, B. P.↗
NASA NTRS1975

Environmental Health concerns in natural and man-made environments

Industrial hygene and environmental health aspects of ground operation at the Jet Propulsion Laboratory were investigated. Major areas of concern are: (1) toxic substances, (2) noise pollution, (3) electromagnetic radiation; and (4) biohazards and sanitation. Each of these categories are also studied in a closed environment, such as encountered aboard of a spacecraft.

Bergtholdt, C. P.↗
NASA NTRS1977

The Apollo-Soyuz Test Project: Medical report

The results of the clinical aspects as well as the preflight and postflight research studies that were performed on the astronauts are presented. Because of the compromised postflight crew health status, not all postflight research procedures could be accomplished. This compromise was the result of the anomalous entrance of toxic gas into the spacecraft cabin during the earth landing sequence. Despite the exposure, the medical data collected are of sufficient interest to warrant inclusion in this official ASTP Medical Report.

Nicogossian, A. E.↗
NASA NTRS1977

Some basic mathematical methods of diffusion theory

An introductory treatment of the fundamentals of diffusion theory is presented, starting with molecular diffusion and leading up to the statistical methods of turbulent diffusion. A multilayer diffusion model, designed to permit concentration and dosage calculations downwind of toxic clouds from rocket vehicles, is described. The concepts and equations of diffusion are developed on an elementary level, with emphasis on atmospheric applications.

Giere, A. C.↗
NASA NTRS1977

Toxicological aspects of the Skylab program

A current state-of-the-art trace gas removal technology is demonstrated that provides for carbon monoxide removal through an outgassing screening program for nonmetallic materials of the Skylab cabin interior. Material selection included both outgassing data and LD sub 50 information, as well as chemical analyses on pyrolysis products to prevent toxic inhalation exposures of spacecrews.

Rippstein, W. J., Jr.↗
NASA NTRS1976

Apparent lethal concentrations of pyrolysis products of some polymeric materials

Thirty-nine samples of polymeric materials were evaluated to determine the apparent lethal concentrations of their pyrolysis products. The materials were compared on the basis of the apparent lethal concentration for 50 percent of the test animals. Relative toxicity rankings based o apparent lethal concentration values can differ significantly depending on whether they are based on weight of sample charged or weight of sample pyrolyzed. The ranking of polyphenylene sulfide is particularly sensitive to this difference.

Hilado, C. J.↗
NASA NTRS1977

Extension of pulmonary O2 tolerance in man at 2 ATA by intermittent O2 exposure

To study extension of O2 tolerance by interruption of hyperoxic exposure, five healthy volunteers were exposed to oxygen at 2 ATA on an intermittent schedule of 20 min breathing O2, alternating with 5 min on a normoxic N2-O2 mixture. The cycle was repeated until symptoms or signs of O2 toxicity caused cessation of the experiment. Tracheal irritation and burning on inspiration occurred after 6-9 'oxygen hours' of exposure and progressed to severe tracheobronchial burning sensation, chest pain, and dyspnea after 11-15 h of O2. With intermittent O2 administration, nearly a doubling of the average duration of actual oxygen breathing was required to induce marked vital capacity change (more than 10%) as compared to the previous studies of continuous O2 exposure.

Hendricks, P. L.↗
NASA NTRS1976

A composite system approach to aircraft cabin fire safety

The thermochemical and flammability characteristics of two polymeric composites currently in use and seven others being considered for use as aircraft interior panels are described. The properties studied included: (1) limiting oxygen index of the composite constituents; (2) fire containment capability of the composite; (3) smoke evolution from the composite; (4) thermogravimetric analysis; (5) composition of the volatile products of thermal degradation; and (6) relative toxicity of the volatile products of pyrolysis. The performance of high-temperature laminating resins such as bismaleimides is compared with the performance of phenolics and epoxies. The relationship of increased fire safety with the use of polymers with high anaerobic char yield is shown. Processing parameters of one of the bismaleimide composites is detailed.

Kourtides, D. A.↗
NASA NTRS1977

Assessment of relative flammability and thermochemical properties of some thermoplastic materials

Thermomechanical properties, flammability, oxygen index, relative toxicity of pyrolysis effluents, and char yields were studied for 12 advanced polymers which are candidates for use in aircraft interiors as decorative films, compression- and injection-molded parts and thermoplastic parts. Polymers sampled included polyphenylene sulfide, 9,9 bis (4-hydroxyphenol) fluorene polycarbonate-poly (dimethylsiloxane), polyether sulfone, polyvinyl fluoride and polyvinylidene fluoride. Availability of these samples, whether in commercial form or in test quantities, is specified. An estimate of relative fire resistance for the materials was obtained; the five polymers listed above were found to be the most fire resistant of the 12 sampled.

Kourtides, D. A.↗
NASA NTRS1977

Aircraft interior sandwich panel development

Three resin systems (bismaleimide, polyimide and modified phenolic) and several decorative films for use in aircraft interior panelling were subjected to flammability, smoke and gas emission, and toxicity testing. Cost, weight and appearance were also taken into account in assessing the feasibility of the materials for applications in passenger seating areas as well as in unoccupied compartments (galleys, lavatories, closets). Heat release studies and burn-through tests provided an additional measure of the fire safety characteristics of the panelling. A modified phenolic resin system and Tedlar-polycarbonate decorative film were selected as the most promising candidates for replacing conventional epoxy resin-impregnated fiberglass materials.

Anderson, R. A.↗
NASA NTRS1977

Bisphenol A polycarbonate as a reference material

Test methods require reference materials to standardize and maintain quality control. Various materials have been evaluated as possible reference materials, including a sample of bisphenol A polycarbonate without additives. Screening tests for relative toxicity under various experimental conditions were performed using male mice exposed to pyrolysis effluents over a 200-800 C temperature range. It was found that the bisphenol A polycarbonate served as a suitable reference material as it is available in large quantities, and does not significantly change with time.

Hilado, C. J.↗
NASA NTRS1978

Cryostat safety tent

Transparent vinyl tent is designed for easy assembly with minimum use of handtools. Tent prevents toxic or explosive vapors from entering building. Frame posts are mounted on casters to allow easy mobility.

Millman, J. L.↗
NASA NTRS1979

Heat resistant nontoxic laminate

Light-weight low-cost laminate used to replace epoxy compound panels is suitable for auto, railcar, and aircraft structural parts. Physical and thermal tests show panels made from formulation have better insulative properties, and burn cleaner with less toxic gas generation than panels made with conventional materials.

Kourtides, D. A.↗
NASA NTRS1977

Study to develop improved fire resistant aircraft passenger seat materials, phase 1

The procurement and testing of a wide range of candidate materials is reported. Improved fire resistant nonmetallic materials were subjected to tests to evaluate their thermal characteristics, such as burn, smoke generation, heat release rate and toxicity. In addition, candidate materials were evaluated for mechanical, physical and aesthetic properties. Other properties considered included safety, comfort, durability and maintainability. The fiscal year 1977 and the projected 1980 cost data were obtained for aircraft seat materials.

Trabold, E. L.↗