SEARCH · Search NASA
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Sputtering technique forms transition-metal interstitial compounds into superconducting thin films having transition temperatures similar to those of the bulk materials. Since the magnetic-field and current-carrying properties of the films exceed those of the bulk materials, they may have applications other than in tunneling devices.
Thermodynamic behavior of interstitial elements in Mo, W, Nb, and Ta
Contribution of interstitial sinks to creep strength of niobium- and tantalum-based alloys determined by effect on activation energy for creep
Structural and mechanical effects of interstitial sinks in niobium and alloys of niobium and tantalum
Thermal insulating characteristics of low conductance interstitial materials under compressive loads, noting carbon paper and wire screens
Transition metal interstitial compounds thin film preparation and superconducting properties, emphasizing high critical temperature, rock salt structure and NbN base
Internal friction, Young modulus and resistivity measurements for stage I interstitials in electron irradiated tungsten
Thermal isolation characteristics of low conductance interstitial materials determined, using test apparatus of axially loaded radiation shielded cylindrical column in vacuum
Interstitial sinks effects on high temperature structural and creep behavior of niobium and niobium-zirconium alloy
Preparation and electrochemical testing methods for fuel cell catalysts using interstitial compounds
Interstitial Cl molecule formation in NaCl lattice, computing strain field and energetics by energy minimization technique based on point ion lattice model
Thermodynamic properties of interstitial solid solutions with fcc metals from atomically discrete model by computer simulation
Binary interstitial solid solutions thermodynamic properties calculation with Kirkwood expansion, allowing crystal first order partition function measurement without degeneracy error
Ternary solid solutions with substitutional and interstitial solute atoms, developing statistical mechanical interaction model
A previous calculation of the thermodynamic properties of interstitial solid solutions based on the technique of Kirkwood expansions has been extended to include the effects of second nearest neighbor solute atom mutual interactions. The error inherent in the first order (or quasi-chemical) counting of the degeneracy of the solution crystal is avoided. It is shown that, at high temperatures, even strong second nearest neighbor solute mutual interactions have a negligible effect on the entropy of the solution and a small, temperature-dependent effect on the solute partial enthalpy.
Fracture toughness and cyclic crack propagation data for Ti-5Al-2.5Sn extra-low interstitial (ELI) castings, 0.51 and 2.54 cm (0.20 and 1.00 in.) thick, at 394, 294, 77, and 20 K (250, 70, -320, and -423 F), are presented. Both surface flaw and compact tension geometries were tested. Comparison is made with other titanium alloys in both wrought and cast forms. Crack propagation resistance is comparable to wrought Ti-5Al-2.5Sn ELI, even with the extremely coarse as-cast grain size encountered.
Resolution of digital imagery increased by calculating estimated values of intensity at coordinate points between original intensity-data points. Calculator implements algorithm that generates such interstitial points using four-by-four array of convolute integer coefficients. Coefficients multiplied by intensities at 16 original image points nearest each interstice to obtain weighted average intensity at each interstice.
A microporous structure with layered interstitial surface treatments, and the method and apparatus for its preparation are disclosed. The structure is prepared by sequentially subjecting a uniformly surface treated structure to atomic oxygen treatment to remove an outer layer of surface treatment to a generally uniform depth, and then surface treating the so exposed layer with another surface treating agent. The atomic oxygen/surface treatment steps may optionally be repeated, each successive time to a lesser depth, to produce a microporous structure having multilayered surface treatments. The apparatus employs at least one side arm from a main oxygen-containing chamber. The side arm has characteristic relaxation times such that a uniform atomic oxygen dose rate is delivered to a specimen positioned transversely in the side arm spaced from the main gas chamber.