Ethiopian rift and plateaus - Some volcanic petrochemical differences
Volcanic petrochemical differences of Ethiopian rift and plateaus
Mohr, P. A.↗
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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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Relative elevation differences revealed by near infrared CO2 bands on Mars
Relative elevation differences on Mars surface revealed by near IR carbon dioxide bands spectroscopic observations
Woszczyk, A.↗
Spectroscopic determination of surface pressure and elevation differences on Mars
Mars surface pressure and elevation differences determined by spectroscopic observation of carbon dioxide band
Cruikshank, D. P.↗
Sex differences in body weight regulation in rats following lateral hypothalamic lesions
Sex differences in rat body weight regulation due to lateral hypothalamic lesions
Cox, V. C.↗
Difference analogues of quasi-linear elliptic Dirichlet problems with mixed derivatives
Difference analogs of Dirichlet problem for second order quasi-linear elliptic operators with mixed derivatives, using discretization method
Stepleman, R. S.↗
Sleep of unrestrained chimpanzee - Differences between first and last rapid eye movement periods
First and last rapid eye movement /REM/ sleep differences in unrestrained chimpanzee
Adey, W. R.↗
The computation of supersonic flow fields about wing-body combinations by 'shock-capturing' finite difference techniques
Supersonic flow field computation for wing-body combinations by shock-capturing finite difference techniques, discussing improvement based on Runge-Kutta method
Kutler, P.↗
Core binding energy difference between bridging and nonbridging oxygen atoms in a silicate chain
Core binding energy difference between bridging and nonbridging oxygen atoms in silicate chain of pyroxenes, using X ray photoelectron spectra
Adler, I.↗
Oxidation of TD nickel at 1050 C and 1200 C as compared with three grades of nickel of different purity
The isothermal oxidation of three nickels of different purity, Ni-200, Ni-270, and JM-Ni, was compared with that of TD-Ni in air at 1050 and 1200 C. The samples were oxidized as ground, as polished, or as annealed and polished. Weight change, metal loss, scale thickness, oxide morphology, and scale texture were determined. In degree of oxidation, TD-Ni was nearly the same as the higher purity materials, Ni-270 and JM-Ni; and less pure Ni-200 oxidized more than the others. However, in microstructure and scale texture the TD-Ni more closely resembled Ni-200. Grinding only charged the texture of the oxides of Ni_200 and TD-Ni.
Lowell, C. E.↗
An Implicit Finite Difference Solution to the Viscous Radiating Shock Layer with Strong Blowing
An implicit finite difference scheme is developed for the fully coupled solution of the viscous radiating stagnation line equations, including strong blowing. Solutions are presented for both air injection and carbon phenolic ablation products injection into air at conditions near the peak radiative heating point in an earth entry trajectory from interplanetary return missions. A detailed radiative transport code that accounts for the important radiative exchange processes for gaseous mixtures in local thermodynamic and chemical equilibrium is utilized.
Garrett, L. B.↗
Finite difference solution to the three-dimensional, incompressible thermal energy boundary-layer equation
An implicit numerical method has been adopted for the solution to the three-dimensional, energy boundary-layer equation. The energy equation is written in terms of a dimensionless temperature function, the relative stagnation-enthalpy difference, and transformed by the introduction of a Blasius-type transformation of coordinates as well as dimensionless stream functions. The method is applied to the problem consisting of an infinite cylinder joined with its axis perpendicular to a thin, flat, heated plate. A Prandtl number equal to one is simply considered.
Fillo, J. A.↗
Investigation of mass transfer between two parallel walls at different temperatures by a moment method
One-dimensional flow between two fixed parallel walls composed of the same substance but at different temperatures and spaced a distance 1 apart is considered. The hot plate is the evaporating surface (source) and the cold plate is the condensing surface (sink). The vapor between the two plates is assumed to be a monatomic gas consisting of Maxwell molecules. Lee's moment method is used to obtain a set of six nonlinear equations. Both the nonlinear equations and a linearized approximation to them are solved.
Sloat, T. N.↗
Wind tunnel measurements of surface pressure fluctuations at Mach numbers of 1.6, 2.0, and 2.5 using 12 different transducers
The turbulent boundary layer on the wall of a 9 by 7 foot wind tunnel was measured with 12 different transducers at Mach numbers of 1.6, 2.0, and 2.5. The results indicated that the wall surface-pressure-fluctuation field was more homogeneous at a Mach number of 2.5 than at Mach numbers of 1.6 or 2.0. A comparison of power-spectral-density data at Mach 2.5 with a summary of similar data (Mach 0.1 to 3.45) showed good agreement. The measurement uncertainty was greatest when frequencies were low and the surface-pressure-fluctuation field was homogeneous. The uncertainty at higher frequencies increased as the surface-pressure-fluctuation field became more inhomogeneous. Since transducer mounting effects and system noise levels were determined not to have contributed appreciably to measurement uncertainties, the result was attributed to an interaction between the surface-pressure-fluctuation field and the transducers. Corcos' correction for size effects improved the comparison between transducers at the high frequencies, but did not eliminate an apparent size effect at the lower frequencies.
Lewis, T. L.↗
Computation of space shuttle flow fields using noncentered finite-difference schemes.
Second- and third-order, noncentered finite-difference schemes are described for the numerical solution of the hyperbolic equations of fluid dynamics. The advantages of noncentered methods over the more conventional centered schemes are: simpler programming logic, nonhomogeneous terms are easily included, and generalization to multidimensional problems is direct. Second- and third-order methods are compared with regard to dissipative and dispersive errors and shock-capturing ability. These schemes are then used in a shock-capturing technique to determine the inviscid, supersonic flow field surrounding space shuttle vehicles (SSV). Resulting flow fields about typical pointed and blunted, delta-winged SSVs at angle of attack are presented and compared with experiment.
Kutler, P.↗
Differences in apparent straightness of dot and line stimuli.
An investigation has been made of anisotropic responses to contoured and noncontoured stimuli to obtain an insight into the way these stimuli are processed. For this purpose, eight subjects judged the alignment of minimally contoured (3 dot) and contoured (line) stimuli. Stimuli, presented to each eye separately, vertically subtended either 8 or 32 deg visual angle and were located 10 deg left, center, or 10 deg right in the visual field. Location-dependent deviations from physical straightness were larger for dot stimuli than for lines. The results were the same for the two eyes. In a second experiment, subjects judged the alignment of stimuli composed of different densities of dots. Apparent straightness for these stimuli was the same as for lines. The results are discussed in terms of alternative mechanisms for analysis of contoured and minimally contoured stimuli.
Parlee, M. B.↗
Eigenvalues of singular differential operators by finite difference methods. I.
Approximation of the eigenvalues of certain self-adjoint operators defined by a formal differential operator in a Hilbert space. In general, two problems are studied. The first is the problem of defining a suitable Hilbert space operator that has eigenvalues. The second problem concerns the finite difference operators to be used.
Baxley, J. V.↗
A finite-difference method for transonic airfoil design.
This paper describes an inverse method for designing transonic airfoil sections or for modifying existing profiles. Mixed finite-difference procedures are applied to the equations of transonic small disturbance theory to determine the airfoil shape corresponding to a given surface pressure distribution. The equations are solved for the velocity components in the physical domain and flows with embedded shock waves can be calculated. To facilitate airfoil design, the method allows alternating between inverse and direct calculations to obtain a profile shape that satisfies given geometric constraints. Examples are shown of the application of the technique to improve the performance of several lifting airfoil sections. The extension of the method to three dimensions for designing supercritical wings is also indicated.
Steger, J. L.↗
A simple performance calculation method for LH2/LOX engines with different power cycles
A simple method for the calculation of the specific impulse of an engine with a gas generator cycle is presented. The solution is obtained by a power balance between turbine and pump. Approximate equations for the performance of the combustion products of LH2/LOX are derived. Performance results are compared with solutions of different engine types.
Schmucker, R. H.↗