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Results for “X-Ray Spectroscopy”

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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NASA NTRS1971

Stress corrosion in titanium alloys and other metallic materials

Multiple physical and chemical techniques including mass spectroscopy, atomic absorption spectroscopy, gas chromatography, electron microscopy, optical microscopy, electronic spectroscopy for chemical analysis (ESCA), infrared spectroscopy, nuclear magnetic resonance (NMR), X-ray analysis, conductivity, and isotopic labeling were used in investigating the atomic interactions between organic environments and titanium and titanium oxide surfaces. Key anhydrous environments studied included alcohols, which contain hydrogen; carbon tetrachloride, which does not contain hydrogen; and mixtures of alcohols and halocarbons. Effects of dissolved salts in alcohols were also studied. This program emphasized experiments designed to delineate the conditions necessary rather than sufficient for initiation processes and for propagation processes in Ti SCC.

Harkins, C. G.↗
NASA NTRS1974

Solar flares

A review of the knowledge about solar flares which has been obtained through observations from the earth and from space by various methods. High-resolution cinematography is best carried out at H-alpha wavelengths to reveal the structure, time history, and location of flares. The classification flares in H alpha according to either physical or morphological criteria is discussed. The study of flare morphology, which shows where, when, and how flares occur, is important for evaluating theories of flares. Consideration is given to studies of flares by optical spectroscopy, radio emissions, and at X-ray and XUV wavelengths. Research has shown where and possibly why flares occur, but the physics of the instability involved, of the particle acceleration, and of the heating are still not understood.

Zirin, H.↗
NASA NTRS1971

Space astronomy and upper atmospheric sounding

The discoveries and activities of the Space Science Program are reported. Results of studies are presented for the following areas: gamma and x-ray astronomy, optical geophysics and solar wind, infrared astronomy, radio astronomy, and rocket spectroscopy. Lists of publications, talks, and conferences are included.

Friedman, H.↗
NASA NTRS1974

Astronomy satellites in the U.S. program

The Orbiting Astronomical Observatory (OAO) series demonstrated that necessary thermal control systems and high pointing stability are feasible on astronomical satellites. A geosynchronous International Ultraviolet Explorer (IUE) is being planned by the US, UK, and ESRO for stellar spectroscopy. High Energy Astronomy Observatories, HEAO-A B, and C, will concentrate on stellar X-ray objects, cosmic ray physics, and gamma ray astronomy. A Shuttle-compatible Solar Maximum Mission (SMM) is planned for studying solar flares and flare related phenomena during the next solar maximum. Now in the instrumentation definition stage is the Large Space Telescope (LST), to provide higher resolution and sensitivity, larger wavelength range (from ultraviolet to far infrared), and higher time resolution than ground-based telescopes.

Aucremanne, M. J.↗
NASA NTRS1974

Solid state polymerization and crystallography of polyimide precursors

Although the production of crystallinity in a polymeric system has historically led to commerically useful properties, the polyimides, prized for their high temperature characteristics, as customarily synthesized by melt or solution casting, are amorphous. It is shown that polymide containing residual crystallinity can be synthesized by isothermal annealing of crystals of the salt of the diisopropyl ester of pyromellitic acid and phenylene diamine. The reaction is topochemical in that the geometry of the polymer product is dependent upon that of the crystalline precursor. Infrared spectroscopy reveals the presence of imide absorption in the polymer, while powder diffractometry suggests residual crystallinity. Single crystal X-ray analysis of the monomer yields a structure of chains of alternating acid and base suggesting that the monomer is amenable to polymerization with a minimum of geometrical disruption.

Wakelyn, N. T.↗
NASA NTRS1966

Pi-mesic X-rays

Pion-meson X-ray spectra of calcium, titanium, and aluminum energy shifts

TITANIUM↗