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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 937 records · Page 52
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

Ecology and thermal inactivation of microbes in and on interplanetary space vehicle components

The heat resistance of Bacillus subtilis var. niger was measured from 85 to 125 C using moisture levels of % RH or = 0.001 to 100. Curves are presented which characterize thermal destruction using thermal death times defined as F values at a given combination of three moisture and temperature conditions. The times required at 100 C for reductions of 99.99% of the initial population were estimated for the three moisture conditions. The linear model (from which estimates of D are obtained) was satisfactory for estimating thermal death times (% RH or = 0.07) in the plate count range. Estimates based on observed thermal death times and D values for % RH = 100 diverged so that D values generally gave a more conservative estimate over the temperature range 90 to 125 C. Estimates of Z sub F and Z sub L ranged from 32.1 to 58.3 C for % RH of or = 0.07 and 100. A Z sub D = 30.0 was obtained for data observed at % RH or = 0.07.

Reyes, A. L.↗
NASA NTRS1974

Small scale photo probability sampling and vegetation classification in southeast Arizona as an ecological base for resource inventory

The author has identified the following significant results. The broad scale vegetation classification was developed for a 3,200 sq mile area in southeastern Arizona. The 31 vegetation types were derived from association tables which contained information taken at about 500 ground sites. The classification provided an information base that was suitable for use with small scale photography. A procedure was developed and tested for objectively comparing photo images. The procedure consisted of two parts, image groupability testing and image complexity testing. The Apollo and ERTS photos were compared for relative suitability as first stage stratification bases in two stage proportional probability sampling. High altitude photography was used in common at the second stage.

Johnson, J. R.↗
NASA NTRS1976

Particles, environments and possible ecologies in the Jovian atmosphere

The eddy diffusion coefficient is estimated as a function of altitude, separately for the Jovian troposphere and mesosphere. Complex organic molecules produced by the Ly alpha photolysis of methane may possibly be the absorbers in the lower mesosphere which account for the low reflectivity of Jupiter in the near ultraviolet. The optical frequency chromophores are localized at or just below the Jovian tropopause. Candidate chromophore molecules must satisfy the condition that they are produced sufficiently rapidly that convective pyrolysis maintains the observed chromophore optical depth. The condition is satisfied if complex organic chromophores are produced with high quantum yield by NH3 photolysis at less than 2,300 A. Jovian photoautotrophs in the upper troposphere satisfy this condition well, even with fast circulation, assuming only biochemical properties of comparable terrestrial organisms. An organism in the form of a thin, gas filled balloon can grow fast enough to replicate if (1) it can survive at the low mesospheric temperatures, or if (2) photosynthesis occurs in the troposphere.

Sagan, C.↗
NASA NTRS1975

CARETS: A prototype regional environmental information system. Volume 9: Shore zone land use and land cover; Central Atlantic Regional Ecological Test Site

Anderson's 1972 United States Geological Survey classification in modified form was applied to the barrier-island coastline within the CARETS region. High-altitude, color-infrared photography of December, 1972, and January, 1973, served as the primary data base in this study. The CARETS shore zone studied was divided into six distinct geographical regions; area percentages for each class in the modified Anderson classification are presented. Similarities and differences between regions are discussed within the framework of man's modification of these landscapes. The results of this study are presented as a series of 19 maps of land-use categories. Recommendations are made for a remote-sensing system for monitoring the CARETS shore zone within the context of the dynamics of the landscapes studied.

Coastal ecosystems↗
NASA NTRS1976

Monitoring the extent and occurence of fire in the different veld types of South Africa with particular reference to it's ecological role

The author has identified the following significant results. Imagery showed the highest amount of burned area to be in the western, southern, and eastern Transvaal and in one scene of the Transkei coast region. The percentage of burned area per image in all instances exceeded 1.4% reaching a maximum of 8.24% equivalent to 121,758 ha out of 1,476,540 ha of one image in the eastern Transvaal lowveld. There was a consistent increase in the amount of burnt area on images from July through to the end of October. From October onwards, there was a decrease in burned area so that during December there was none or very little burning evident. Four scenes comprising nine images showed burning according to the twelve veld types. Considerable variation was evident in the burning between different veld types: between 10 and 19% of the mixed, sourish-mixed, and sour bushveld types was burnt, but in other veld types the percentage of burnt area was less than 1%.

Edwards, D.↗
NASA NTRS1977

Investigation of the effects of construction and stage filling of reservoirs on the environment and ecology: Preproject baseline

The author has identified the following significant results: (1) LANDSAT imagery can be used effectively as a baseline for detection of environmental change, resulting from construction of a major inland reservoir. (2) Forest cover can be observed adequately on two-band composite enlargements at a scale of 1:130,000. (3) Forest cover delineated on LANDSAT enlargements compares accurately with ground truth at a scale of 1:250,000. (4) A dual image mapping technique superimposing winter, summer, and spring scenes using the zoom transfer scope facilitates the determination. (5) The same technique can be used to detect changes in the project area, resulting from construction activities. (6) High altitude aircraft imagery can also be used to interpret changes in land use and forest type. (7) Construction operations can be more clearly detailed on the air photos than on LANDSAT imagery.

Riggins, R. E.↗
NASA NTRS1977

Monitoring the extent and occurrence of fire in the different veld types of South Africa with particular reference to its ecological role and role in range management

The author has identified the following significant results. Veld burning was recorded from LANDSAT imagery covering approximately 75 million ha or 62% of the surface of the eastern part of South Africa. All basic data on the location, areas, and numbers of burns for 10 biomes, composed of 67 veld types, are available on 1:250,000 and 1:500,000 map overlays, and are summarized on small scale maps showing fire distribution and amount burned in classes per 15 minute square of latitude and longitude. Veld burning is not randomly distributed, but is almost continuous over a broad belt, widest in the north and narrowing southeastwards, and then southwestwards between the eastern escarpment and the area. It is shown that over almost the whole sea, the overall pattern of veld burning is clearly marked out as early as July in midwinter, subsequent development being merely an intensification of the pattern.

Edwards, D.↗
NASA NTRS1977

Investigation of environmental change pattern in Japan. Investigation of the ecological environment index from observation of the regional vegetation cover and their growing condition

The author has identified the following significant results. Practical use of recognition results of LANDSAT data as the base map of the field survey or the retouching work of vegetation and land use has the effective benefit to cut down the cost, labor, and time lower than 10% of a conventional method. Correct and detailed vegetation maps were prepared using combined interpretation of repetition of data of different seasons at warm and temperate forested areas.

Maruyasu, T.↗