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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 559 records · Page 31

All sources NASA NTRS DOE OSTI

NASA NTRS1989

Evaluation of transport conditions during physical vapor transport growth of opto-electronic crystals

Transport conditions were evaluated during the vapor phase growth of mercurous chloride crystals in a closed tube. Experimentally observed growth rates were much smaller than those calculated by the Hertz-Knudsen (H-K) equation. The Arrhenius behavior of growth rate with the temperature was used to derive the sticking coefficient. A one-dimensional diffusion model was used to calculate the total mass flux and was compared with the condensing flux. It was predicted that growth occurred in the convecto-diffusive range.

Singh, N. B.↗

NASA NTRS1992

Analysis of the ionosphere-plasmasphere transport of superthermal electrons. I - Transport in the plasmasphere

Analytical solutions are developed for the kinetic equation which describes the transport of superthermal electrons in the terrestrial plasmasphere, together with a relationship which makes it possible to calculate the transparency of the plasmasphere to these electrons. In addition, analytic expressions are presented for the heating rate of the thermal plasma due to the passage of these superthermal electrons through the plasmasphere.

Khazanov, George V.↗

NASA NTRS1922

The world's air transportation services : data as to passengers, mail, and goods carried by American and European transportation services

This report presents detailed descriptions, statistics, and graphs on European and American air transport. The European countries listed are Belgium, Czecho-Slovakia, Denmark, France, Germany, Great Britain, Holland, and Italy.

Source record↗

NASA NTRS1992

Advanced transportation system study: Manned launch vehicle concepts for two way transportation system payloads to LEO. Work breakdown structure and work breakdown structure dictionary

The report describes the work breakdown structure (WBS) and its associated WBS dictionary for task area 1 of contract NAS8-39207, advanced transportation system studies (ATSS). This WBS format is consistent with the preliminary design level of detail employed by both task area 1 and task area 4 in the ATSS study and is intended to provide an estimating structure for parametric cost estimates.

Duffy, James B.↗

NASA NTRS1996

Transportation Systems Analyses (TSA): Highly Reusable Space Transportation (HRST). A preliminary programmatic assessment

This report overviews the strategic implications of the Highly Reusable Space Transportation (HRST) program. The analysis postulates the anticipated HRST market (window is 2006-30, with a 2015 focus). Next the analysis speculates on market 'price of entry' for several potential markets. HRST is envisioned as a NASA overlay to either the STS modernization or the on-going RLV initiative. Three NASA options are reviewed. An example HRST program (MagLifter + RBCC RLV) is assessed in terms of financial/political issues. The merits of HRST-vs-RLV are briefly examined. Finally, a Small Launch Vehicle (SLV) HRST application is reviewed.

Duffey, Jack↗

NASA NTRS1961

Random Deviations from Cruise Altitudes of a Turbojet Transport at Altitudes of a Turbojet Transport at Altitudes between 20,000 and 41,000 Feet

An evaluation has been made of the random deviations from the cruise altitudes (called flight technical error) of a large turbojet transport on scheduled, passenger-carrying operations over the Eastern United States, the Atlantic Ocean, and Western Europe. Data were collected from l9O flights through an altitude range of 20,000 to 41,000 feet and for a time period from January to August 1959. The results of the investigation, based on an evaluation of the altitude recordings of an NASA VGH recorder, showed that for a high percentage of the total cruise time (99.0 percent) the airplane operated within 100 feet of its stabilized cruise altitude. On occasion, however, the excursions of the airplane from the cruise altitude reached large values (in excess of 1,000 feet in the worst case).

Gracey, William↗

NASA NTRS1998

Intestinal transport of gentamicin with a novel, glycosteroid drug transport agent

PURPOSE: The objective was to investigate the ability of a glycosteroid (TC002) to increase the oral bioavailability of gentamicin. METHODS: Admixtures of gentamicin and TC002 were administered to the rat ileum by injection and to dogs by ileal or jejunal externalized ports, or PO. Bioavailability of gentamicin was determined by HPLC. 3H-TC002 was injected via externalized cannulas into rat ileum or jejunum, or PO and its distribution and elimination was determined. The metabolism of TC002 in rats was evaluated by solid phase extraction and HPLC analysis of plasma, urine and feces following oral or intestinal administration. RESULTS: The bioavailability of gentamicin was substantially increased in the presence of TC002 in both rats and dogs. The level of absorption was dependent on the concentration of TC002 and site of administration. Greatest absorption occurred following ileal orjejunal administration. TC002 was significantly more efficacious than sodium taurocholate, but similar in cytotoxicity. TC002 remained primarily in the GI tract following oral or intestinal administration and cleared rapidly from the body. It was only partly metabolized in the GI tract, but was rapidly and completely converted to its metabolite in plasma and urine. CONCLUSIONS: TC002 shows promise as a new drug transport agent for promoting intestinal absorption of polar molecules such as gentamicin.

Non-NASA Center↗

DOE OSTI2013