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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 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

New experimental contributions to understanding the effect of ultrasonic irradiation on tomatoes

Irradiation of Aurora 100 tomatoes by a hydrodynamic ultrasonic generator with a frequency of 25 kHz per sec intensifies seed germination and the growth of the plants, causing precosity and increasing the output by 15.63 to 37.65%. The most effective radiation time (between 20 and 40 min) intensifies the phenophases. It causes some increase in output and changes in the chemical compositions of the fruits.

Elena, A.↗
NASA NTRS1974

Studies on propagation of microbes in the airborne state

An investigation was conducted to demonstrate whether airborne microbes could propagate. The procedure consisted of: (1) looking for dilution of a labelled base in DNA; (2) looking for labelling of DNA by mixing aerosols of the label and the cells; (3) examining changes in cell size; (4) testing the possibility of spore germination; and (5) seeking evidence of an increase in cell number. Results indicate that growth and propagation can occur under special conditions, principally at temperatures of approximately 30 C (87 F) and water activity equivalents of 0.95 to 0.98.

Dimmick, R. L.↗
NASA NTRS1975

Ecology and Thermal Inactivation of Microbes in and on Interplanetary Space Vehicle Components

Spores of Bacillus subtilis var. niger were heat treated in aqueous suspension at 90 C, and observed for morphological changes and loss of viability. The 5 logs reduction that occurred in broth at 90 min required 210 min in buffered water. Five characteristic changes observed after spores were exposed 120 min at 90 C in buffered water were: (1) 90% loss of spore viability, (2) 5% stainability, (3) 76% increase in spore size (as observed by scanning electron microscopy), (4) 21% of spore areas remaining refractile, and (5) an increase of 77% in packed cell volume (PCV). Stainability and PCV changes were recognized only after secondary exposure in broth. Extended heat exposure (3 h at 90 C) resulted in 99% loss of spore viability and 99% loss of stainability. After 4 hours of heat exposure, 90% of the cells disintegrated. These results suggest that early germinal changes occurr concurrently with the early changes in the heat susceptibility of dormant spores.

Reyes, A. L.↗
NASA NTRS1981

Microorganisms and biomolecules in space hard environment

Microorganisms and biomolecules exposed to space vacuum and to different intensities of selected wavelengths of solar ultraviolet radiation is studied. The influence of these factors, applied singly or simultaneously, on the integrity of microbial systems and biomolecules is measured. Specifically, this experiment will study in Bacillus subtilis spores (1) disturbances in subsequent germination, outgrowth, and colony formation; (2) photochemical reactions of the DNA and protein in vivo and in vitro and their role in biological injury; and (3) the efficiency of repair processes in these events.

Horneck, G.↗
NASA NTRS1981

Environmental factors during seed development and their influence on pre-harvest sprouting in wheat

The problem of pre-harvest sprouting of wheat is surveyed and a literature review of the effects of environmental conditions on pre-harvest sprouting is presenting. Physiological, biochemical, and morphological changes occurring within the wheat seed during germination, harvest, and storage are discussed. The effects of moisture, humidity, and temperature, particularly on seed dormancy, are considered. Procedures used in Europe for predicting the potential for sprouting are evaluated.

Ciha, A. J.↗
NASA NTRS1981

Exploring the moon

The genesis of lunar exploration programs is described. The idea that the dead moon could give important clues about the origin of the solar system germinated into plans for a soft landing on the moon and then into the Apollo program. The exchanges between NASA scientists and other astronomers that led to these plans are recounted.

Jastrow, R.↗
NASA NTRS1984

Effects of simulated weightlessness on mammalian development. Part 1: Development of clinostat for mammalian tissue culture and use in studies on meiotic maturation of mouse oocytes

The effects of weightlessness on three aspects of mammalian reproduction: oocyte development, fertilization, and early embryogenesis was studied. Zero-gravity conditions within the laboratory by construction of a clinostat designed to support in vitro tissue culture were simulated and the effects of simulated weightlessness on meiotic maturation in mammalian oocytes using mouse as the model system were studied. The timing and frequency of germinal vesicule breakdown and polar body extrusion, and the structural and numerical properties of meiotic chromosomes at Metaphase and Metaphase of meiosis are assessed.

Wolegemuth, D. J.↗
NASA NTRS1984

Space environment effects (M0006)

The effects of long term exposure to the near Earth space environment on advanced electrooptical and radiation sensor components were examined. The effect of long duration spaceflight on the germination rate of selected terrestrial plant seeds is observed in exobiological experiments.

Angelo, J. A., Jr.↗
NASA NTRS1984

Results of the Purdue University GAS-1 payload

The Purdue University GAS-1 payload was flown on STS-7. Results of the three experiments included in the payload are summarized. The experiments conducted were: (1) the detection of nuclear particles in near-Earth space environment, (2) an investigation of the effect of microgravity on the germination of sunflower seeds, and (3) an examination of the motion of mercury under low gravity conditions. Results of the payload experiments are discussed from an engineering design standpoint. Data were obtained from one of the experiments, but electrical and mechanical malfunctions prevented the operation of the other two. The thermal control design maintained the desired temperatures and the structure successfully supported all components. The microprocessor collected and stored temperature readings and other data during the flight. A series of recommendations based on these results are included herein.

Perez, R.↗
NASA NTRS1984

El Paso/Yslete schools Get-Away Special Space Shuttle student projects

Student projects for the Get Away Special (GAS) space shuttle program were summarized. Experimental topics included: seed germination, shrimp growth, liquid lasers, planaria regeneration, fluid dynamics (wicking), soil molds, antibiotics, crystallization, the symbiosis of yeast and fungi, and the performance of electronic chips. A brief experimental design is included for each project.

Azar, S. S.↗
NASA NTRS1984

An investigation of the phototropic effect on seedling orientation in a microgravity environment: A student involvement project

A microgravity growth chamber was designed to investigate the phototropic response of radish seedlings. Enclosed in a one fourth inch thick, hexagonal, fiberglass-foam spacepak nineteen inches across corners, the experiment consists of a growth chamber and germination tray, a water reservoir and solenoid valve, a fluorescent light for photo simulation, a Minolta X700 camera with programmable back, a 50 mm macro lens and flash, a battery pack, and a computer controller. Two temperature sensors and one light sensor located in the walls of the growth chamber provide temperature and illumination data. A computer provides 8 K command and 34 K data storage capability. The experiment was not activated during the STS flight because a malfunctioning latching relay stuck and reduced the battery power level.

Barainca, J. W.↗
NASA NTRS1984

Project Explorer: Get Away Special #007

Tentatively scheduled to fly on STS-17 (41G), this get away special aims to demonstrate amateur radio transmissions to global ground stations in the English language. Experiments No. 1, 2, and 3 use the micro-gravity of space flight to study the solidification of lead-antimony and aluminum-copper alloys, the germination of radish seeds, and the growth of potassium-tetracyanoplatinate hydrate crystals in an aqueous solution. Flight results are to be compared with Earth-based data. Experiment No. 4 (the Marshall Amateur Radio Club Experiment - MARCE) features radio transmissions and also provides timing for the start of all other experiments. A microprocessor obtains real-time data from all experiments as well as temperature and pressure measurements within the GAS canister. These data are to be transmitted on previously announced amateur radio frequencies after they are converted into the English language by a digitalker for general reception. The support structure for the G #007 experiments consists of two primary plates and four bumper assemblies.

Henderson, A. J., Jr.↗
NASA NTRS1984

Project Explorer

PROJECT EXPLORER is a program that will fly student-developed experiments onboard the Space Shuttle in NASA's Get-Away Special (GAS) containers. The program is co-sponsored by the Alabama Space and Rocket Center, the Alabama-Mississippi Section of the American Institute of Aeronautics and Astronautics, Alabama A&M University and requires extensive support by the University of Alabama in Huntsville. A unique feature of this project will demonstrate transmissions to ground stations on amateur radio frequencies in English language. Experiments Nos. 1, 2, and 3 use the microgravity of space flight to study the solidification of lead-antimony and aluminum-copper alloys, the growth of potassium-tetracyanoplatinate hydrate crystals in an aqueous solution, and the germination of radish seeds. Flight results will be compared with Earth-based data. Experiment No. 4 features radio transmission and will also provide timing for the start of all other experiments. A microprocessor will obtain real-time data from all experiments as well as temperature and pressure measurements taken inside the canister. These data will be transmitted on previously announced amateur radio frequencies after they have been converted into the English language by a digitalker for general reception.

Dannenberg, K. K.↗
NASA NTRS1985

Energy-modelled climb and climb-dash - The Kaiser technique

F. Kaiser's germinal 1944 report on his 'resultant-height' concept, now known as energy modelling, is reviewed. The data base for the Me. 262 jet fighter is recreated via spline-lattice representation of specific excess power. Minimum-time and 'distance'-climb trajectories are generated in an attempt to check Kaiser's results. Agreement is good for the minimum-time calculations but only qualitative agreement is obtained for the mysterious 'distance climbs' whose documentation is fragmentary. The character of optimal climb-dash trajectories in energy approximation is examined and illustrated.

Merritt, S. R.↗
NASA NTRS1984

Effects of clinostat rotation on mouse meiotic maturation in vitro

The effects of microgravity on meiosis, fertilization, and early embryonic development in mammals are being examined by using a clinostat to reorient the cells with respect to the gravity vector. A clinostat capable of supporting mammalian cells in tissue culture has been developed. Initial studies have focused on examining the effects of clinostat rotation on meiotic maturation in mouse oocytes. Oocytes recovered from ovarian follicles were subjected to clinostat rotation on a horizontal or vertical axis or to static conditions for a 16 hr period. No gross morphological changes and no effects on germinal vesicle breakdown were observed under any rotation conditions (1/4, 1, 10, 30, 100 RPM). Success of meiotic progression to Metaphase II was comparable among experimental and control groups except at 100 RPM, where a slight inhibition was observed.

Wolgemuth, D. J.↗
NASA NTRS1986

Modification of cytogenetic and physiological effects of space flight factors by biologically active compounds

Physiological and cytogenetic changes in the Welsh onion plants induced by a short (82 days) and long term (522 days) space flight are expressed in decrease of seed germination, inhibition of stem growth, depression of cell division in root meristem, and increase in the number of structural chromosome rearrangements. The treatment of such plants with solutions of a-tocopherol, auxin, and kinetin decreased the level of chromosome aberrations to the control one and normalized cell divisions and growth partly or completely.

Aliyev, A. A.↗
NASA NTRS1991

Capillary-Effect Root-Environment System

Capillary-effect root-environment system (CERES) is experimental apparatus for growing plants in nutrient solutions. Solution circulated at slight tension in cavity filled with plastic screen and covered by porous plastic membrane. By adsorptive attraction, root draws solution through membrane. Conceived for use in microgravity of space, also finds terrestrial application in germinating seedlings, because it protects them from extremes of temperature, moisture, and soil pH and from overexposure to fertilizers and herbicides.

Wright, Bruce D.↗