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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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Vacuum UV emission features dissociative excitation by electron impact on molecular hydrogen and oxygen, measuring excitation cross sections from threshold to 350 eV
K-LL Auger spectra of nitrogen, oxygen, carbon monoxide, nitrogen oxide, water and carbon dioxide, using double focusing electrostatic electron spectrometer
Molecular oxygen dissociative excitation in vacuum UV by electron impact, discussing resonance triplet atomic emission cross section
Night airglow oxygen Herzberg I bands covariation with O I 5577 A line, evaluating NASA 1968 airborne auroral measurements
Saturating flash delayed luminescence from chloroplasts, considering relationship to oxygen evolution
Heat-transfer coefficients were obtained on a thrust chamber which simulated the geometry of the NERVA nuclear rocket. The tests were performed with and without peripheral film cooling over a chamber pressure range of 1.05 million to 5.84 million newtons per square meter (153 to 847 psia). With no film cooling, the overall axial variation in the value of the correlation coefficient C of the equation (Stanton)* (Prandtl)* to the 0.7ths power = C(Reynolds)* to the -0.2ths power, where * indicates the reference enthalpy condition, was reduced 66 percent when the local diameter in the Reynolds number was replaced by the axial distance from the injector face. The average peak values of C were reduced 25 percent with 2 and 3.75 percent cooling and 50 percent with 7.5 percent cooling.
Auxiliary power units operating on hydrogen and oxygen have the potential for significantly improved performance and payload for space shuttle vehicles. A recuperated open cycle hydrogen-oxygen turbine driven power system concept with pressure modulated reactant control is considered. The reference system, the control mode, component arrangement, performance potential, and the technology program for this system are discussed.
A quantitative analysis is made of a linear four-step model for photosynthetic molecular oxygen evolution in which each photochemical trapping center or an associated enzyme cycles through five oxidation states. Based on data obtained with isolated chloroplasts, a number of aspects were considered, including the two perturbations which damp the oscillation of the oxygen flash yield in a flash sequence. The kinetics and the mechanism of deactivation was another aspect investigated.
Clean Re surfaces were produced by the Ar(+) ion bombardment technique. Results reported previously by Farnsworth and Zehner (1969) for the adsorption of CO and molecular oxygen on the (0001) Re surface were confirmed. The exposure of a (0001) Re surface to CO at elevated crystal temperatures produced no additional structures. Neither increased surface defect densities nor excitation of the adsorbate enhanced the adsorption characteristics of CO or molecular oxygen on the surfaces studied.
By analyzing all existing frequency data of the oxygen molecule in microwave, submillimeter, and infrared spectroscopy, a new set of molecular parameters is obtained. The parameters are tabulated and compared with values obtained by other authors. Observed and calculated frequencies of oxygen lines are also given.
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Rate coefficient data for the recombination reaction H + 02 + Ar yields H02 + Ar have been determined from studies of lean hydrogen-oxygen mixtures behind incident shock waves over the temperature range of 948 to 1125 K. Hydroxyl radical concentration profiles were measured by ultraviolet absorption spectroscopy, and rate data were obtained through analysis of induction time and exponential growth parameter data. Analysis of the data yielded a rate coefficient which was generally lower than most of the more recent values obtained from shock tube studies. The effect of boundary layer formation on the conditions behind the shock was also examined and found to be negligible.
A dispersion-strengthened alloy, TD nickel chromium (TDNiCr) is being developed for use on the thermal protection system of the space shuttle at temperatures up to 1204 C(2200 F). Manufacturing processes were developed for the fabrication of sheet and foil to specifications. The addition of aluminum to the basic TDNiCr composition provides outstanding oxidation resistance up to 1260 C(2300 F); aluminum levels of 2 to 4% are considered optimum for space shuttle application.
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Configuration interaction (CI) variational trial functions (which assure formally correct dissociation) and the single-configuration self-consistent-field approximation are applied to the calculation of the excited electronic states of the negatively charged oxygen molecule. The energy curves and wave functions of these states are analyzed. All the excited states are found to have equilibrium-internuclear separations at least 1 a.u. larger than the ground state. The two lowest energy states are characterized, respectively, as shape and valence Feshbach resonances.
Auxiliary power units operating on hydrogen and oxygen have the potential for significantly improved performance and payload for the Space Shuttle vehicles. In order to identify the technologies required for these units and to identify promising system configurations, contracted studies provided component and system-configuration screening analysis and detailed analysis of two preliminary system layouts. From these studies, Lewis Research Center has selected for further investigation a recuperated open-cycle hydrogen-oxygen turbine-driven APU concept with pressure-modulated reactant control. This paper discusses the reference system, the control mode, component arrangement, performance potential, and the technology program for this system.