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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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

Low energy ionizing collisions between N2 and CO beam molecules and CO, N2, NO, CH4, and CO2 target molecules

Absolute total negative charge production cross sections for N2 + CO, CO + N2, CO + CO, N2 + NO, N2 + CH4, and N2 + CO2 collisions are reported, and a simple model of collisions is discussed. The cross sections were measured to within about 1 eV of their thresholds. Specific reaction channels were investigated by referring to mass spectrometric identification of the product ions scattered in the forward direction, and these product ion identifications were used to explain characteristic structures in the total charge production cross sections in the near-threshold regions. The extent of the importance of dissociative ionization and 'simple' ionization in the studied collisions at low energy is considered, and charge transfer cross sections for (CO)+ + CO, CO(+) + CH4, and N2(+) + CH4 are presented.

Utterback, N. G.↗
NASA NTRS1984

The metal-carbonyl bond in Ni(CO)4 and Fe(CO)5 - A clear-cut analysis

A detailed analysis of the metal-carbonyl bonding in Ni(CO)4 and Fe(CO)5, based on the newly developed contained space orbital variation (CSOV) method, is carried out to investigate various contributing factors to the interaction. Three aspects about the metal-CO interaction are presented: (1) the frozen orbital repulsion between the metal 4s and the CO is large; (2) the metal to CO pi donation is energetically much more important than the CO to the metal sigma donation; and (3) the metal 4s and 4p orbitals make a very small contribution (smaller than 0.4 eV) to the interaction energy; the largest portion of this contribution arises from the CO to metal sigma donation.

Bauschlicher, C. W., Jr.↗
NASA NTRS1975

Vibrational energy exchange in CO-CO collisions at low temperature

The V-V exchange rates for CO in the ground electronic state have been measured at a temperature of 75 K. The rates determined were for the processes CO(nu = n) + CO(nu = 0) yields CO(nu = n - 1) + CO(nu = 1) - increment E, with n lying in the closed interval from 2 to 8. The values obtained are close to published 100 K data, thus indicating an insensitivity to temperature. It appears that multirotational quantum jumps may be important in explaining the measured rates.

Gower, M. C.↗
NASA NTRS1980

Hot corrosion of Co-Cr, Co-Cr-Al, and Ni-Cr alloys in the temperature range of 700-750 deg C

The effect of SO3 pressure in the gas phase on the Na2SO4 induced hot corrosion of Co-Cr, Ni-Cr, and Co-Cr-Al alloys was studied in the temperature range 700 to 750 C. The degradation of the Co-Cr and Ni-Cr alloys was found to be associated with the formation of liquid mixed sulfates (CoSO4-Na2SO4 or NiSO4-Na2SO4) which provided a selective dissolution of the Co or Ni and a subsequent sulfidation oxidation mode of attack which prevented the maintenance of a protective Cr2O3 film. A clear mechanism was not developed for the degradation of Co-Cr-Al alloys. A pitting corrosion morphology was induced by a number of different mechanisms.

Chiang, K. T.↗
NASA NTRS1985

CO adsorption on (111) and (100) surfaces of the Pt sub 3 Ti alloy. Evidence for parallel binding and strong activation of CO

The CO adsorption on a 40 atom cluster model of the (111) surface and a 36 atom cluster model of the (100) surface of the Pt3Ti alloy was studied. Parallel binding to high coordinate sites associated with Ti and low CO bond scission barriers are predicted for both surfaces. The binding of CO to Pt sites occurs in an upright orientation. These orientations are a consequence of the nature of the CO pi donation interactions with the surface. On the Ti sites the orbitals donate to the nearly empty Ti 3d band and the antibonding counterpart orbitals are empty. On the Pt sites, however, they are in the filled Pt 5d region of the alloy band, which causes CO to bond in a vertical orientation by 5 delta donation from the carbon end.

Mehandru, S. P.↗
NASA NTRS1985

Diurnal CO variations in the Venus mesosphere from CO microwave spectra

Microwave spectra of CO in the Venus mesosphere were measured and analyzed in order to provide mixing profiles. The results indicate that there is a significant dependence of the observed spectra on the phase of Venus. This dependence is tied to a diurnal variation in the vertical profile of CO mixing ratios with the local solar zenith angle. Spectra of the nightside hemisphere are characterized by very little absorption in the wings of the spectra, yet very deep absorption in the line center. Dayside spectra exhibit considerably greater absorption in the line wings and less absorption in the line center. Solutions for the CO mixing profile derived from spectra show that the nightside atmosphere contains two to four times the CO abundance above about 95 km relative to the dayside atmosphere above 95 km. Conversely, the dayside atmosphere between 80 and 90 km shows two to four times the CO abundance for the same altitude region in the nightside atmosphere.

Clancy, R. T.↗
NASA NTRS1988

Studies of CW lasing action in CO2-CO, N2O-CO, CO2-H2O, and N2O-H2O mixtures pumped by blackbody radiation

A proof of principle experiment to evaluate the efficacy of CO and H2O in increasing the power output for N2O and CO2 lasing mixtures has been conducted and theoretically analyzed for a blackbody radiation-pumped laser. The results for N2O-CO, CO2-CO, N2O-H2O and CO2-H2O mixtures are presented. Additions of CO to the N2O lasant increased power up to 28 percent for N2O laser mixtures, whereas additions of CO to the CO2 lasant, and the addition of H2O to both the CO2 and N2O lasants, resulted in decreased output power.

Abel, Robert W.↗
NASA NTRS2026

In-suit CO 2 Washout Test System (ICWTS) for CO 2 Washout Verification in Spacesuits

Since the time of Mercury, Gemini, and Apollo, NASA has been performing CO 2 washout verification of spacesuits with Human in the Loop (HITL) test methods. Classically, the only instrumentation both with the accuracy and response time necessary was that of external mass spectrometers or medical gas analyzers fed by a long capillary line from the oro-nasal region within the suit. The helmet CO 2 washout configuration including the challenges posed by variation of a suited human subject frequently created difficulty in capturing adequate breath by breath data. For example, a nasal cannula could be worn with reasonable comfort however it posed the following challenges: (1) impeded the test subject’s ability to do a proper Valsalva maneuver; (2) frequently provided a corrupted waveform with relative movement; (3) precluded the ability to evaluate the Flow Weighted Average (FWA) at subject interface. A mouthpiece could be used in lieu of a cannula but posed challenges as well: (1) created potential disturbances of the flow field; (2) precluded the test subject from speaking during usage; and (3) presented comfort issues limiting the duration of test points. These challenges made it impractical to use a mouthpiece for anything other than short lab ambient environment tests. Technology development and NASA investment have afforded new capabilities to address some of these measurements providing improved data collection and are implemented in the In-suit CO 2 Washout Test System (ICWTS) which provides suit inlet/outlet pressure, temperature, relative humidity, partial pressure of oxygen, partial pressure of CO 2 , and flow measurement coupled with the acquisition of the inspired PPCO 2 including the ability for FWA measurement. This test system, coupled with use of the In-suit Respiration Mannequin Assembly (IRMA) and Computational Fluid Dynamics (CFD) combine to provide a full picture of the in-suit oro-nasal flow field and effectiveness of CO 2 washout in a spacesuit design.

Colin Campbell↗
NASA NTRS1980

Electron-temperature dependence of dissociative recombination of electrons with CO(+)-(CO)n-series ions

A microwave afterglow mass spectrometer apparatus is used to determine the dependence on electron temperature T sub e of the recombination coefficients alpha sub n of the dimer and trimer ions of the series CO+.(CO) sub n. It is found that alpha sub 1 = (1.3 + or - 0.3)x 0.000001 (T sub e(K)/300) to the -0.34; and alpha sub 2 = (1.9 + or - 0.4)x 0.000001 (T sub e(K)/300) to the -0.33 cu cm/sec. These dependences on T sub e are quite different from those obtained previously for polar-cluster ions of the hydronium and ammonium series but are similar to that for simple diatomic ions.

Whitaker, M.↗